LeoZotos/sciq_topic · Datasets at Hugging Face

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What causes the particles of medium to move parallel to the direction of the wave?	a gorge	disturbance theory	fluid waves	longitudinal waves	Longitudinal waves cause the particles of medium to move parallel to the direction of the wave.	physics
Which state of matter lacks a fixed volume, fixed shape, and consists of charged particles?	latin units	hydrogen giants	sedentary	ions	Plasma is a state of matter that lacks a fixed volume and a fixed shape and consists of charged particles called ions. Because it consists of charged particles, plasma can conduct electricity and respond to a magnetic field.	physics
What type of cell transmits electrical impulses in the nervous system?	epithelial	toxin cell	Large Cell	nerve cell	cell that transmits electrical impulses in the nervous system; commonly called nerve cell.	biology
What is the force pushing a rocket called?	ponds	electron microscope	terrible interference	thrust	Most halogens have a variety of important uses. A few are described in the Table below .	physics
In headwater streams, what plant process is mostly attributed to algae that are growing on rocks?	graduation	12-18 breaths	baby	photosynthesis	Abiotic features of rivers and streams vary along the length of the river or stream. Streams begin at a point of origin referred to as source water. The source water is usually cold, low in nutrients, and clear. The channel (the width of the river or stream) is narrower here than at any other place along the length of the river or stream. Headwater streams are of necessity at a higher elevation than the mouth of the river and often originate in regions with steep grades leading to higher flow rates than lower elevation stretches of the river. Faster-moving water and the short distance from its origin results in minimal silt levels in headwater streams; therefore, the water is clear. Photosynthesis here is mostly attributed to algae that are growing on rocks; the swift current inhibits the growth of phytoplankton. Photosynthesis may be further reduced by tree cover reaching over the narrow stream. This shading also keeps temperatures lower. An additional input of energy can come from leaves or other organic material that falls into a river or stream from the trees and other plants that border the water. When the leaves decompose, the organic material and nutrients in the leaves are returned to the water. The leaves also support a food chain of invertebrates that eat them and are in turn eaten by predatory invertebrates and fish. Plants and animals have adapted to this fast-moving water. For instance, leeches (phylum Annelida) have elongated bodies and suckers on both ends. These suckers attach to the substrate, keeping the leech anchored in place. In temperate regions, freshwater trout species (phylum Chordata) may be an important predator in these fast-moving and colder river and streams.	biology
What is the term that refers to stored chemical energy in organic matter or wastes?	pigments	codeine	sodium and solvent	biomass energy	The stored chemical energy in organic matter or wastes is called biomass energy. The organic matter may be trees or other plants, or it may be wastes from homes and industries. When biomass is burned, it produces thermal energy that can be used for heating homes, cooking, or generating electricity. Biomass—especially wood—is an important energy source in the poorer nations where most people can’t afford fossil fuels. However, burning biomass releases air pollution and contributes to global climate change. Biomass can be used to make ethanol, a fuel that is added to gasoline. Although ethanol releases less pollution than gasoline, large areas of land are needed to grow the plants needed to make it (see Figure below ). This reduces the amount of land available for food production.	chemistry
The process of photosynthesis ultimately gets powered by what kind of energy?	shallower	genetic drift	precipitates	light		biology
A binary molecular compound is a molecular compound that is composed of what?	four elements	two atoms	four atoms	two elements	A binary molecular compound is a molecular compound that is composed of two elements. In general, the elements that combine to form binary molecular compounds are both nonmetals. This contrasts with ionic compounds, which usually involve bonds between metal ions and nonmetal ions. Because ionic charges cannot be used to name these compounds or to write their formulas, a different naming system must be used for molecular compounds. Another difference between ionic and molecular compounds is that two nonmetal atoms will frequently combine with one another in a variety of ratios. For example, nitrogen and oxygen combine to make several binary compounds, including NO, NO 2 , and N 2 O. Obviously they can’t all be called nitrogen oxide! How would someone know which one you were talking about? Each of the three compounds has very different properties and reactivity. A system to distinguish between compounds such as these is necessary.	chemistry
Within the first 8 weeks of gestation, a developing embryo establishes the rudimentary structures of all of its organs and tissues from the ectoderm, mesoderm, and endoderm. this process is called what?	homeobox genes	ultraviolet rays	the chest cavity	organogenesis	Within the first 8 weeks of gestation, a developing embryo establishes the rudimentary structures of all of its organs and tissues from the ectoderm, mesoderm, and endoderm. This process is called organogenesis. Like the central nervous system, the heart also begins its development in the embryo as a tube-like structure, connected via capillaries to the chorionic villi. Cells of the primitive tube-shaped heart are capable of electrical conduction and contraction. The heart begins beating in the beginning of the fourth week, although it does not actually pump embryonic blood until a week later, when the oversized liver has begun producing red blood cells. (This is a temporary responsibility of the embryonic liver that the bone marrow will assume during fetal development. ) During weeks 4–5, the eye pits form, limb buds become apparent, and the rudiments of the pulmonary system are formed. During the sixth week, uncontrolled fetal limb movements begin to occur. The gastrointestinal system develops too rapidly for the embryonic abdomen to accommodate it, and the intestines temporarily loop into the umbilical cord. Paddle-shaped hands and feet develop fingers and toes by the process of apoptosis (programmed cell death), which causes the tissues between the fingers to disintegrate. By week 7, the facial structure is more complex and includes nostrils, outer ears, and lenses (Figure 28.15). By the eighth week, the head is nearly as large as the rest of the embryo’s body, and all major brain structures are in place. The external genitalia are apparent, but at this point, male and female embryos are indistinguishable. Bone begins to replace cartilage in the embryonic skeleton through the process of ossification. By the end of the embryonic period, the embryo is approximately 3 cm (1.2 in) from crown to rump and weighs approximately 8 g (0.25 oz).	biology
What goes through different larval stages?	intervertebral foramen	olivary tubules	mortality	crustaceans	Figure 28.41 All crustaceans go through different larval stages. Shown are (a) the nauplius larval stage of a tadpole shrimp, (b) the cypris larval stage of a barnacle, and (c) the zoea larval stage of a green crab. (credit a: modification of work by USGS; credit b: modification of work by Mª. Mingorance Rodríguez; credit c: modification of work by B. Kimmel based on original work by Ernst Haeckel).	biology
What is the major cause of chronic respiratory disease as well as cardiovascular disease and cancer?	mold	drinking	exercise	smoking	Smoking is the major cause of chronic respiratory disease as well as cardiovascular disease and cancer. Exposure to tobacco smoke by smoking or by breathing air that contains tobacco smoke is the leading cause of preventable death in the United States. Regular smokers die about 10 years earlier than nonsmokers do. The Centers for Disease Control and Prevention (CDC) describes tobacco use as "the single most important preventable risk to human health in developed countries and an important cause of [early] death worldwide. " Simply stated: Stopping smoking can prevent many respiratory diseases.	biology
Monotremes, marsupials, and placental mammals are subclasses of what?	reefs	digested	reptiles	mammals	Monotremes, marsupials, and placental mammals are subclasses of mammals. Almost all living mammals are placental mammals, which are divided into many orders.	biology
What type of mammal gives birth to young that need to develop further in the mother's pouch after birth?	Cleaning	humans	whales	marsupials	Marsupials give birth to a tiny, immature embryo. The embryo then continues to grow and develop in a pouch on the mother’s belly. This is less risky for the mother. However, the embryo is fragile, so it may be less likely to survive than the fetus of a placental mammal.	biology
What is the measure of how closely molecules are packed together?	the mass quadruples	healing magnet	convection insulators	density	Density is mass per unit volume. Density is a measure of how closely molecules are packed together. The closer together they are, the greater the density. Since air is a gas, the molecules can pack tightly or spread out.	physics
What is the leading cause of lung cancer?	hypha	feeding	cocoon stage	tobacco smoke	Tobacco smoke contains dozens of carcinogens, including nicotine and formaldehyde. Exposure to tobacco smoke is the leading cause of lung cancer.	biology
The golgi removes some sugar monomers and substitutes others, producing a large variety of what?	proteins	flow law	four atoms	carbohydrates		chemistry
Parenchymal, collenchymal, and sclerenchymal cells are associated with what types of living things?	fungi	primates	parasites	plants	Different types of plant cells include parenchymal, collenchymal, and sclerenchymal cells. The three types differ in structure and function.	biology
What is the name of the location in which a stream or river starts?	mouth	spring	shore	source	All streams and rivers have several features in common. These features are shown in ( Figure below ). The place where a stream or river starts is its source. The source might be a spring, where water flows out of the ground. Or the source might be water from melting snow on a mountain top. A single stream may have multiple sources. A stream or river probably ends when it flows into a body of water, such as a lake or an ocean. A stream ends at its mouth. As the water flows into the body of water, it slows down and drops the sediment it was carrying. The sediment may build up to form a delta.	geography
What disease occurs when cells in the breast grow out of control and form a tumor?	omniverous	adult breast growth	repolarization	breast cancer	Breast cancer is the most common type of cancer in females. It occurs when cells in the breast grow out of control and form a tumor. Breast cancer is rare in teens but becomes more common as females get older. Regular screening is recommended for most women starting around age 40. If found early, breast cancer usually can be cured with surgery.	biology
What process refers to the changes that occur in populations of living organisms over time?	variation	in the lymph	adaptation	evolution	The term evolution describes the changes that occur in populations of living organisms over time. Describing these changes does not address the origin of life. The two are commonly and mistakenly confused. Biological evolution likewise says nothing about cosmology, the Big Bang, or where the universe, galaxy, solar system, or Earth came from.	biology
Alkenes can react with what to form alcohols?	magnet	air	proteins	water	Alkenes can react with water to form alcohols.	chemistry
Wind blown sand contributes to what type of erosion?	immune system	modification	sedimentary	abrasion	Did you ever see workers sandblasting a building to clean it? Sand is blown onto the surface to scour away dirt and debris. Wind-blown sand has the same effect. It scours and polishes rocks and other surfaces. Wind-blown sand may carve rocks into interesting shapes. You can see an example in Figure below . This form of erosion is called abrasion. It occurs any time rough sediments are blown or dragged over surfaces. Can you think of other ways abrasion might occur?.	geography
Bases are ionic compounds consisting of hydroxide ions and a what?	sulfate	cinion	carbonate	cation	Bases are ionic compounds consisting of hydroxide ions and a cation. Naming and formula writing for bases follows the same guidelines as for other ionic compounds.	chemistry
What causes the menstrual cycle to be repeated?	ovaries	gravity	uteris	lack of fertilization	The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. It includes changes in the uterus as well as development of an egg and ovulation. If fertilization does not occur, menstruation occurs and the cycle repeats.	biology
What happens when turgid cells in a nonwoody tissue push against each other?	the tissues merge	wasp	the tissue melts	the tissue stiffens		biology
What is the waxy substance that epidermal cells secrete?	saliva	cellulose	bile	cuticle	Dermal tissue covers the outside of a plant in a single layer of cells called the epidermis. You can think of the epidermis as the plant’s skin. It mediates most of the interactions between a plant and its environment. Epidermal cells secrete a waxy substance called cuticle , which coats, waterproofs, and protects the above-ground parts of plants. Cuticle helps prevent water loss, abrasions, infections, and damage from toxins.	biology
What is the length of the route between two points?	velocity	pons	direction	distance	Distance is the length of the route between two points. The distance of a race, for example, is the length of the track between the starting and finishing lines. In a 100-meter sprint, that distance is 100 meters.	geography
According to the first law of thermodynamics, what can neither be created nor destroyed?	light	fuel	Leukemogenesis	energy	Chapter 46 1 Figure 46.8 According to the first law of thermodynamics, energy can neither be created nor destroyed. Eventually, all energy consumed by living systems is lost as heat or used for respiration, and the total energy output of the system must equal the energy that went into it. 3 Figure 46.17 C: Nitrification by bacteria converts nitrates (NO3−) to nitrites (NO2−). 4 D 6 B 8 A 10 D 12 D 14 B 16 A 18 A 20 C 21 Food webs show interacting groups of different species and their many interconnections with each other and the environment. Food chains are linear aspects of food webs that describe the succession of organisms consuming one another at defined trophic levels. Food webs are a more accurate representation of the structure and dynamics of an ecosystem. Food chains are easier to model and use for experimental studies. 23 Grazing food webs have a primary producer at their base, which is either a plant for terrestrial ecosystems or a phytoplankton for aquatic ecosystems. The producers pass their energy to the various trophic levels of consumers. At the base of detrital food webs are the decomposers, which pass this energy to a variety of other consumers. Detrital food webs are important for the health of many grazing food webs because they eliminate dead and decaying organic material, thus, clearing space for new organisms and removing potential causes of disease. By breaking down dead organic matter, decomposers also make mineral nutrients available to primary producers; this process is a vital link in nutrient cycling. 25 NPE measures the rate at which one trophic level can use and make biomass from what it attained in the previous level, taking into account respiration, defecation, and heat loss. Endotherms have high metabolism and generate a lot of body heat. Although this gives them advantages in their activity level in colder temperatures, these organisms are 10 times less efficient at harnessing the energy from the food they eat compared with cold-blooded animals, and thus have to eat more and more often. 27 Many factors can kill life in a lake or ocean, such as eutrophication by nutrient-rich surface runoff, oil spills, toxic waste spills, changes in climate, and the dumping of garbage into the ocean. Eutrophication is a result of nutrient-rich runoff from land using artificial fertilizers high in nitrogen and phosphorus. These nutrients cause the rapid and excessive growth of microorganisms, which deplete local dissolved oxygen and kill many fish and other aquatic organisms.	physics
What are the three primary pigment colors?	red, green, blue	red, white, blue	allele frequency	cyan, yellow, magenta	Pigments are substances that color materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. The primary pigment colors are cyan, yellow, and magenta. They can be combined to produce all other colors.	biology
How do organophostbate pesticides work?	inhibiting testosterone	inhibiting reticulum	inhibiting cryptosporidium	inhibiting acetylcholinesterase		biology
In the case of a light bulb, electricity is converted to light and what kind of energy?	chemical	rust	infrared waves	thermal	Most circuits have devices such as light bulbs that convert electric energy to other forms of energy. In the case of a light bulb, electricity is converted to light and thermal energy.	physics
Where in relation to the home, are levels of vocs found to be higher?	outdoors	niche	in Fields	indoors	The processes of evolution are fundamental to much of biology. Why do people have such a hard time understanding them?.	geography
Density and pressure of air decreases with what?	surface friction	temperature	30	altitude	Like density, the pressure of the air decreases with altitude. There is less air pressing down from above the higher up you go. Look at the bottle in Figure below . It was drained by a hiker at the top of a mountain. Then the hiker screwed the cap on the bottle and carried it down to sea level. At the lower altitude, air pressure crushed it. Can you explain why?.	physics
Energy is absorbed in the process of converting a liquid at its boiling point into a what?	neons	strongest surface area	plasma	gas	Energy is absorbed in the process of converting a liquid at its boiling point into a gas. As with the melting of a solid, the temperature of a boiling liquid remains constant and the input of energy goes into changing the state. The molar heat of vaporization of a substance is the heat absorbed by one mole of that substance as it is converted from a liquid to a gas. As a gas condenses to a liquid, heat is released. The molar heat of condensation of a substance is the heat released by one mole of that substance as it is converted from a gas to a liquid. Since vaporization and condensation of a given substance are the exact opposite processes, the numerical value of the molar heat of vaporization is the same as the numerical value of the molar heat of condensation, but opposite in sign. In other words, .	physics
Images in what type of mirror are reversed left and right but not reversed top and bottom?	convex	low and wide	virtual	plane mirror	Images in a plane mirror are reversed left and right but not reversed top and bottom.	physics
What do cells produce as they age?	oxidants	carcinogens	wrinkles	proto-oncogenes		biology
The body of the simplest sponges takes the shape of a cylinder with a large central cavity, called?	curve	land mass	belt	spongocoel	The body of the simplest sponges takes the shape of a cylinder with a large central cavity, the spongocoel. Water enters the spongocoel from numerous pores in the body wall. Water flows out through a large opening called the osculum (Figure 15.9). However, sponges exhibit a diversity of body forms, which vary in the size and branching of the spongocoel, the number of osculi, and where the cells that filter food from the water are located. Sponges consist of an outer layer of flattened cells and an inner layer of cells called choanocytes separated by a jellylike substance called mesohyl. The mesohyl contains embedded amoeboid cells that secrete tiny needles called spicules or protein fibers that help give the sponge its structural strength. The cell body of the choanocyte is embedded in mesohyl but protruding into the spongocoel is a mesh-like collar surrounding a single flagellum. The beating of flagella from all choanocytes moves water through the sponge. Food particles are trapped in mucus produced by the sieve-like collar of the choanocytes and are ingested by phagocytosis. This process is called intracellular digestion. Amoebocytes take up nutrients repackaged in food vacuoles of the choanocytes and deliver them to other cells within the sponge.	physics
Laid on dry land by reptiles, amniotic eggs have what that prevents them from drying out?	oil coating	tannin	double yolks	waterproof membranes	Loggerhead turtles spend most of their life in the ocean. Adult female loggerheads go ashore briefly to lay their eggs in the sand. Then they return to the water and leave the eggs to hatch on their own. Figure below shows baby loggerheads on a beach shortly after hatching. The baby turtles must make their way back to the water, hopefully without being snatched up by a predator. Loggerhead turtles are reptiles. Unlike amphibians, turtles and other reptiles can lay their eggs on dry land. That’s because they produce amniotic eggs. Amniotic eggs have waterproof membranes to prevent them from drying out.	biology
What three rs represent the steps that you personally can take to conserve our natural resources and minimize waste?	reduce, reuse, re-educate	rinse, reuse, recycle	remove, reduce, reuse	reduce, reuse, recycle	Reduce, reuse, and recycle. There are steps that you personally can take to conserve our natural resources and reduce waste. The waste that an individual creates is small in proportion to all the waste produced by society. Yet all small contributions, when added up, make a difference.	biology
What is the process that allows organisms with better traits to survive and produce?	comparative mutations	spontaneous mutation	Spermatogenesis	natural selection	Evolution occurs by natural selection, the process by which organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Evolution is due to differences in the survival and reproduction of individuals within a population.	biology
What is the term for a substance that increases the rate of a chemical reaction but is not changed or used up in the reaction?	a contribute	purification	repel	a catalyst	Some reactions need extra help to occur quickly. They need another substance, called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction but is not changed or used up in the reaction. The catalyst can go on to catalyze many more reactions.	chemistry
What type of compounds can form crystals?	molecular compounds	integral compounds	magnetic compounds	ionic compounds	Many compounds form molecules, but ionic compounds form crystals instead. A crystal consists of many alternating positive and negative ions bonded together in a matrix. Look at the crystal of sodium chloride (NaCl) in the Figure below . The sodium and chloride ions are attracted to each other because they are oppositely charged, so they form ionic bonds.	chemistry
In grazing, a predator partially eats but does not kill what?	vertical line system	time	pack	prey	In grazing , the predator eats part of the prey but does not usually kill it. You may have seen cows grazing on grass. The grass they eat grows back, so there is no real effect on the population. In the ocean, kelp (a type of seaweed) can regrow after being eaten by fish.	biology
Bone tissues include compact bone, spongy bone, bone marrow, and?	eutheria	slow aging	tourniquet	periosteum	Bone tissues include compact bone, spongy bone, bone marrow, and periosteum.	biology
What type of bacteria causes the disease called tuberculosis?	habitat chart	brain waves	blunt trauma	mycobacterium	Tuberculosis (TB) is a common and often deadly disease caused by a genus of bacterium called Mycobacterium . Tuberculosis most commonly attacks the lungs but can also affect other parts of the body. TB is a chronic disease, but most people who become infected do not develop the full disease. Symptoms include a cough, which usually contains mucus and coughing up blood.	biology
Studies have shown that not only does reproduction have a cost as far as how long male fruit flies live, but also fruit flies that have already mated several times have limited amounts of this?	chromosomes	dna	eggs	sperm	Energy Budgets, Reproductive Costs, and Sexual Selection in Drosophila Research into how animals allocate their energy resources for growth, maintenance, and reproduction has used a variety of experimental animal models. Some of this work has been done using the common fruit fly, Drosophila melanogaster. Studies have shown that not only does reproduction have a cost as far as how long male fruit flies live, but also fruit flies that have already mated several times have limited sperm remaining for reproduction. Fruit flies maximize their last chances at reproduction by selecting optimal mates. In a 1981 study, male fruit flies were placed in enclosures with either virgin or inseminated females. The males that mated with virgin females had shorter life spans than those in contact with the same number of inseminated females with which they were unable to mate. This effect occurred regardless of how large (indicative of their age) the males were. Thus, males that did not mate lived longer, allowing them more opportunities to find mates in the future. More recent studies, performed in 2006, show how males select the female with which they will mate and [3] how this is affected by previous matings (Figure 45.8). Males were allowed to select between smaller and larger females. Findings showed that larger females had greater fecundity, producing twice as many offspring per mating as the smaller females did. Males that had previously mated, and thus had lower supplies of sperm, were termed “resource-depleted,” while males that had not mated were termed “nonresource-depleted. ” The study showed that although non-resource-depleted males preferentially mated with larger females, this selection of partners was more pronounced in the resource-depleted males. Thus, males with depleted sperm supplies, which were limited in the number of times that they could mate before they replenished their sperm supply, selected larger, more fecund females, thus maximizing their chances for offspring. This study was one of the first to show that the physiological state of the male affected its mating behavior in a way that clearly maximizes its use of limited reproductive resources.	biology
What are the two most common causes of diseases?	atomical	dermal tissue	secondary consumers	bacteria and viruses	Today most people realize that microorganisms, such as bacteria or viruses, are the cause of disease. This concept is known as the germ theory of disease, one of the few scientific theories in the field of the life sciences. Although it seems obvious now, people did not always understand the cause of disease. How does a theory such as this become established?.	biology
Organic compounds are defined as covalently bonded compounds containing carbon, excluding carbonates and what else?	anticlines	a neutral one	molarity	oxides	At one time in history, it was thought that only living things were capable of synthesizing the carbon-containing compounds present in cells. For that reason, the term organic was applied to those compounds. Eventually it was proved that carbon-containing compounds could be synthesized from inorganic substances, but the term organic has remained. Currently, organic compounds are defined as covalently bonded compounds containing carbon, excluding carbonates and oxides. By this definition, compounds such as carbon dioxide (CO 2 ) and sodium carbonate (Na 2 CO 3 ) are considered to be inorganic. Organic chemistry is the study of all organic compounds.	chemistry
What drives the turbine in a thermonuclear reactor?	wind energy	magnets	heated oil	heated water or steam	Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. You can see how this might work in the Figure below . In the thermonuclear reactor, radiation from fusion is used to heat water and produce steam. The steam can then be used to turn a turbine and generate electricity.	physics
What is the term for physicians and scientists who research and develop vaccines and treat and study conditions ranging from allergies to aids?	virologists	gaseous chemicals	vaccinologists	immunologists	Immunologist The variations in peripheral proteins and carbohydrates that affect a cell’s recognition sites are of prime interest in immunology. These changes are taken into consideration in vaccine development. Many infectious diseases, such as smallpox, polio, diphtheria, and tetanus, were conquered by the use of vaccines. Immunologists are the physicians and scientists who research and develop vaccines, as well as treat and study allergies or other immune problems. Some immunologists study and treat autoimmune problems (diseases in which a person’s immune system attacks his or her own cells or tissues, such as lupus) and immunodeficiencies, whether acquired (such as acquired immunodeficiency syndrome, or AIDS) or hereditary (such as severe combined immunodeficiency, or SCID). Immunologists are called in to help treat organ transplantation patients, who must have their immune systems suppressed so that their bodies will not reject a transplanted organ. Some immunologists work to understand natural immunity and the effects of a person’s environment on it. Others work on questions about how the immune system affects diseases such as cancer. In the past, the importance of having a healthy immune system in preventing cancer was not at all understood. To work as an immunologist, a PhD or MD is required. In addition, immunologists undertake at least 2–3 years of training in an accredited program and must pass an examination given by the American Board of Allergy and Immunology. Immunologists must possess knowledge of the functions of the human body as they relate to issues beyond immunization, and knowledge of pharmacology and medical technology, such as medications, therapies, test materials, and surgical procedures.	biology
Where are temperatures the lowest?	below	over the oceans	at the equator	at the poles	At the poles, the Sun’s rays are least direct. Much of the area is covered with ice and snow, which reflect a lot of sunlight. Temperatures are lowest here.	geography
Protecting the surface of metal prevents what?	chronic exposure	extraction	instance point	corrosion	One way to prevent corrosion is to protect the surface of the metal. Covering the surface of the metal object with paint or oil will prevent corrosion by not allowing oxygen to contact it. Unfortunately, scratches in the paint or wearing off of the oil will allow the corrosion to begin. Corrosion-sensitive metals can also be coated with another metal that is resistant to corrosion. A “tin can” is actually made of iron coated with a thin layer of tin which protects the iron.	physics
What type of tissues are major barriers to the entry of pathogens into the body?	nasal	skin	vascular	mucosal	The Mucosal Immune Response Mucosal tissues are major barriers to the entry of pathogens into the body. The IgA (and sometimes IgM) antibodies in mucus and other secretions can bind to the pathogen, and in the cases of many viruses and bacteria, neutralize them. Neutralization is the process of coating a pathogen with antibodies, making it physically impossible for the pathogen to bind to receptors. Neutralization, which occurs in the blood, lymph, and other body fluids and secretions, protects the body constantly. Neutralizing antibodies are the basis for the disease protection offered by vaccines. Vaccinations for diseases that commonly enter the body via mucous membranes, such as influenza, are usually formulated to enhance IgA production. Immune responses in some mucosal tissues such as the Peyer’s patches (see Figure 21.11) in the small intestine take up particulate antigens by specialized cells known as microfold or M cells (Figure 21.27). These cells allow the body to sample potential pathogens from the intestinal lumen. Dendritic cells then take the antigen to the regional lymph nodes, where an immune response is mounted.	biology
Trash that gets into fresh and saltwater waterways is called what type of debris?	water	pollution	ocean	aquatic	Most protists consist of a single cell. Some are multicellular but they lack specialized cells.	geography
What is the term for genes that control the expression of other genes within specific regions of cells in the developing organism?	data genes	expression genes	dispersive	gap genes	Gap genes control the expression of other genes within specific regions of cells in the developing organism. This allows specific genes to be expressed in certain cells at the appropriate stage of development.	biology
In vertebrates, what tissue is a type of connective tissue that supports the entire body structure?	lingual tonsils	noninfectious disease	the environment	bone	Complex Tissue Structure As multicellular organisms, animals differ from plants and fungi because their cells don’t have cell walls, their cells may be embedded in an extracellular matrix (such as bone, skin, or connective tissue), and their cells have unique structures for intercellular communication (such as gap junctions). In addition, animals possess unique tissues, absent in fungi and plants, which allow coordination (nerve tissue) of motility (muscle tissue). Animals are also characterized by specialized connective tissues that provide structural support for cells and organs. This connective tissue constitutes the extracellular surroundings of cells and is made up of organic and inorganic materials. In vertebrates, bone tissue is a type of connective tissue that supports the entire body structure. The complex bodies and activities of vertebrates demand such supportive tissues. Epithelial tissues cover, line, protect, and secrete. Epithelial tissues include the epidermis of the integument, the lining of the digestive tract and trachea, and make up the ducts of the liver and glands of advanced animals. The animal kingdom is divided into Parazoa (sponges) and Eumetazoa (all other animals). As very simple animals, the organisms in group Parazoa (“beside animal”) do not contain true specialized tissues; although they do possess specialized cells that perform different functions, those cells are not organized into tissues. These organisms are considered animals since they lack the ability to make their own food. Animals with true tissues are in the group Eumetazoa (“true animals”). When we think of animals, we usually think of Eumetazoans, since most animals fall into this category. The different types of tissues in true animals are responsible for carrying out specific functions for the organism. This differentiation and specialization of tissues is part of what allows for such incredible animal diversity. For example, the evolution of nerve tissues and muscle tissues has resulted in animals’ unique ability to rapidly sense and respond to changes.	biology
Red blood cells don't have a nucleus. this allows them to do what?	heal faster	endosymbiosis	move faster	carry more oxygen	Red blood cells ( Figure below ) are made in the red marrow of long bones, rib bones, the skull, and vertebrae. Each red blood cell lives for only 120 days (about four months). After this time, they are destroyed in the liver and spleen. Mature red blood cells do not have a nucleus or other organelles. Lacking these components allows the cells to have more hemoglobin and carry more oxygen.	biology
The number of electron pairs that hold two atoms together is called?	dynamics	phenomena	filter	bond order	Summary Bond order is the number of electron pairs that hold two atoms together. Single bonds have a bond order of one, and multiple bonds with bond orders of two (a double bond) and three (a triple bond) are quite common. In closely related compounds with bonds between the same kinds of atoms, the bond with the highest bond order is both the shortest and the strongest. In bonds with the same bond order between different atoms, trends are observed that, with few exceptions, result in the strongest single bonds being formed between the smallest atoms. Tabulated values of average bond energies can be used to calculate the enthalpy change of many chemical reactions. If the bonds in the products are stronger than those in the reactants, the reaction is exothermic and vice versa. Saylor URL: http://www. saylor. org/books.	physics
What occurs when the immune system makes an inflammatory response to a harmless antigen?	myoglobin	antibodies	asthma attack	allergies	Allergies occur when the immune system makes an inflammatory response to a harmless antigen. An antigen that causes an allergy is called an allergen.	biology
What energy source, now making a comeback, has helped propel ships and pump water for many years?	solar energy	motile shell	fluorine	wind energy	The whirring blades of these wind turbines look stark against the darkening sky at sunset. The energy of the wind causes the blades to spin, and the energy of the spinning blades is used to generate electricity. People have been using wind for energy for centuries. Until about 200 years ago, for example, ships depended on wind to sail the oceans. And windmills have long been used to gather wind energy to pump water and do other useful work. Today, wind energy is making a comeback. Do you know why? What might be advantages of using the wind for energy? This chapter has the answers.	physics
What is it called when the nucleus of an atom splits into two smaller nuclei?	nuclear fusion	complex fission	flexible energy	nuclear fission	Nuclear fission is the splitting of the nucleus of an atom into two smaller nuclei. This releases a great deal of energy. Nuclear power plants use the energy from nuclear fission to generate electricity.	physics
The curie (ci) is one measure of the rate of what?	growth	spin	division	decay	The curie (Ci) is one measure of the rate of decay (named after Pierre and Marie Curie). One curie is equivalent to 3.7 × 10 10 disintegrations per second. Since this is obviously a large and unwieldy number, radiation is often expressed in millicuries or microcuries (still very large numbers). Another measure is the becquerel (Bq) , named after Henri Becquerel. The becquerel is defined as an activity of one disintegration/second. Both of these units are concerned with the disintegration rate of the radioactive isotope and give no indication of dosage to the target material.	physics
A unique type of organism is also known as what?	element	taxonomy	parasites	species	A species is a unique type of organism. Members of a species can interbreed and produce offspring that can breed (they are fertile). Organisms that are not in the same species cannot do this. Examples of species include humans, lions, and redwood trees. Can you name other examples?.	biology
Snakes use what anatomical structure to smell scents in the air?	zona pellucida	monocots	are not cells	forked tongue	Most reptiles have good eyesight and a keen sense of smell. Snakes smell scents in the air using their forked tongue (see Figure below ). This helps them locate prey. Some snakes have heat-sensing organs on their head that help them find endothermic prey, such as small mammals and birds. Staring into the Beautiful Cold-Blooded Eyes of Reptiles at http://www. environmentalgraffiti. com/news-reptile-eyes is a pictorial display of numerous reptile eyes.	biology
What chemical element helps forms strong bones and teeth in humans?	magnesium	iron	potassium	calcium	Minerals are chemical elements that are essential for body processes. They include calcium, which helps form strong bones and teeth, and potassium, which is needed for normal nerve and muscle function. Good sources of minerals include leafy, green vegetables, whole grains, milk, and meats.	chemistry
The limit to how much solute will dissolve in a given amount of solvent is called what?	strength	density	potency	solubility	Solubility There is usually a limit to how much solute will dissolve in a given amount of solvent. This limit is called the solubility of the solute. Some solutes have a very small solubility, while other solutes are soluble in all proportions. Table 9.2 "Solubilities of Various Solutes in Water at 25°C (Except as Noted)" lists the solubilities of various solutes in water. Solubilities vary with temperature, so Table 9.2 "Solubilities of Various Solutes in Water at 25°C (Except as Noted)" includes the temperature at which the solubility was determined. Table 9.2 Solubilities of Various Solutes in Water at 25°C (Except as Noted).	chemistry
What occurs when hot magma transforms rock that it contacts?	changing metamorphism	existence metamorphism	form metamorphism	contact metamorphism	Contact metamorphism occurs when hot magma transforms rock that it contacts.	physics
What term refers to entities, events or powers regarded as being beyond nature, and cannot be explained by scientific means?	natural	hypothetical	Distinct Chamber Therapy	supernatural	Science is based on the analysis of observations made either through our senses or by using special equipment. Science therefore cannot explain anything about the natural world that is beyond what is observable. The term supernatural refers to entities, events, or powers regarded as being beyond nature, in that such things cannot be explained by scientific means. They are not measurable or observable in the same way the natural world is, and are therefore considered to be outside the realm of scientific examination.	physics
What causes an elastic force in springs?	windchill	velocity	triangles	stretching or compressing	Springs like the ones in Figure below also have elastic force when they are stretched or compressed. And like stretchy materials, they return to their original shape when the stretching or compressing force is released. Because of these properties, springs are used in scales to measure weight. They also cushion the ride in a car and provide springy support beneath a mattress. Can you think of other uses of springs?.	physics
What effect is responsible for flight paths looking curved?	it vibrates	salt water	antioxidants	coriolis effect	Zappy's. Flight paths look curved due to the Coriolis effect . CC BY-NC 3.0.	physics
Wetlands are environments in which the soil is either permanently or periodically saturated with what?	spores	downwelling	oceanic pillar	water	Wetlands Wetlands are environments in which the soil is either permanently or periodically saturated with water. Wetlands are different from lakes and ponds because wetlands exhibit a near continuous cover of emergent vegetation. Emergent vegetation consists of wetland plants that are rooted in the soil but have portions of leaves, stems, and flowers extending above the water’s surface. There are several types of wetlands including marshes, swamps, bogs, mudflats, and salt marshes (Figure 20.33).	geography
When the ground absorbs the water and it settles below the surface it is called what?	precipitation	wastewater	glacier	groundwater		physics
Some metabolic pathways release what by breaking down complex molecules to simpler compounds?	water	renal artery	hydrogen	energy		biology
What is the smallest portion of a crystal lattice?	further apart	updraft	outer electrons	unit cell	A unit cell is the smallest portion of a crystal lattice that shows the three-dimensional pattern of the entire crystal. A crystal can be thought of as the same unit cell repeated over and over in three dimensions. The Figure below illustrates the relationship of a unit cell to the entire crystal lattice.	physics
What is one major cause of skin cancer?	infrared light	fight	aquatic green algae	ultraviolet light	The most important way to keep your skin healthy is to protect it from ultraviolet light. Over-exposure to ultraviolet light can cause skin cancer. Keeping the skin clean can help prevent acne.	biology
Which important decomposers are known to live just about anywhere on earth?	sporozoans	protazoas	viruses	archeans	Archaeans are now known to live just about everywhere on Earth. They are important decomposers. Many live in close relationships with other organisms. They are generally harmless and often beneficial.	biology
In the scientific method, what is the initial, unproven explanation for why something is occurring?	peaks	concepts	plasmid	hypothesis	The scientific method is not a step by step, linear process. It is a way of learning about the world through the application of knowledge. Scientists must be able to have an idea of what the answer to an investigation should be. In order for scientists to make educated guesses about the answers, they will base their guesses on previous knowledge, with the notion of extending that knowledge. Scientists will often make an observation and then form a hypothesis to explain why a phenomenon occurred. They use all of their knowledge and a bit of imagination in their journey of discovery.	physics
What is the name of an element with a different number of neutrons?	visible light	micro microscopes	reaction	isotope	All atoms of the same element have the same number of protons, but some may have different numbers of neutrons. For example, all carbon atoms have six protons, and most have six neutrons as well. But some carbon atoms have seven or eight neutrons instead of the usual six. Atoms of the same element that differ in their numbers of neutrons are called isotopes . Many isotopes occur naturally. Usually one or two isotopes of an element are the most stable and common. Different isotopes of an element generally have the same physical and chemical properties. That’s because they have the same numbers of protons and electrons. For a video explanation of isotopes, go to this URL:.	physics
Nitrogen and sulfur oxides form what type of rain?	heavy rain	common rain	toxic rain	acid rain	Both nitrogen and sulfur oxides are toxic to humans. These compounds can cause lung diseases or make them worse. Nitrogen and sulfur oxides form acid rain, which is described in the next concept.	chemistry
Polyester fabric's resistance to wrinkling comes from the cross-linking of what?	wool strands	thickness and gravity	velocity strands	polymer strands	PET is used in tires, photographic film, food packaging, and clothing. Polyester fabric is used in permanent-press clothing. Its resistance to wrinkling comes from the cross-linking of the polymer strands.	physics
What term refers to the sequence of community and ecosystem changes after a disturbance?	physiological succession	progressions	an omnivore	ecological succession		biology
What is the network of fibers that organizes structures and activities in the cell called?	DNA	enzymes	cytoplasm	cytoskeleton	6.6 The cytoskeleton is a network of fibers that organizes structures and activities in the cell.	biology
Decreasing the volume of a gas and keeping everything else the same will cause its pressure to change in what way?	existence and deduction	orbital state	estradiol	increase	When gas molecules bump into things, it creates pressure. Pressure is greater when gas molecules occupy a smaller space, because greater crowding results in more collisions. This explains why decreasing the volume of a gas increases its pressure.	physics
What evolutionary strategy enables substantial activity during sleep for some animals?	decay	pistills	cenozoic era	adaptation		biology
The cells of the blastocyst form an inner cell mass called the what?	xerophyte	blastocyst	chloroplast	embryoblast	The cells of the blastocyst form an inner cell mass and an outer cell layer, as shown in Figure below . The inner cell mass is called the embryoblast. These cells will soon develop into an embryo. The outer cell layer is called the trophoblast. These cells will develop into other structures needed to support and nourish the embryo.	biology
How do all musical instruments create sound?	conduction	primary pollutant	stimulation	vibration	All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air.	physics
What system disorders include kidney stones, kidney failure, and urinary tract infections?	renal system	nervous system	digestive system	urinary system	Disorders of the urinary system include kidney stones, kidney failure, and urinary tract infections.	biology
What type of respiration has the advantage of releasing more energy?	elastic	kinetic	adaptatioins	aerobic	A major advantage of aerobic respiration is the amount of energy it releases. Without oxygen, organisms can split glucose into just two molecules of pyruvate. This releases only enough energy to make two ATP molecules. With oxygen, organisms can break down glucose all the way to carbon dioxide. This releases enough energy to produce up to 38 ATP molecules. Thus, aerobic respiration releases much more energy than anaerobic respiration.	biology
Major climate types are based on what two things?	always	to horde the water	compressed layer	temperature & precipitation	Major climate types are based on temperature and precipitation. These two factors determine what types of plants can grow in an area. Animals and other living things depend on plants. So each climate is associated with certain types of living things. A major type of climate and its living things make up a biome . As you read about the major climate types below, find them on the map in Figure above .	geography
When amino acids bind together, they form a long chain called what, which is an essential component of protein?	Builds a crust	destroy the membrane	weak bonds	polypeptide	When amino acids bind together, they form a long chain called a polypeptide . A protein consists of one or more polypeptide chains. A protein may have up to four levels of structure. The lowest level, a protein’s primary structure, is its sequence of amino acids. Higher levels of protein structure are described in Figure below . The complex structures of different proteins give them unique properties, which they need to carry out their various jobs in living organisms. You can learn more about protein structure by watching the animation at the following link: http://www. stolaf. edu/people/giannini/flashanimat/proteins/protein%20structure. swf .	chemistry
What type of cells does meiosis produce?	mutated cells	younger adults	diploid daughter cells	haploid daughter cells	Meiosis is a special type of cell division. It produces haploid daughter cells. It occurs when an organism makes gametes. Meiosis is basically mitosis times two. The original diploid cell divides twice. The first time is called meiosis I. The second time is called meiosis II. However, the DNA replicates only once. It replicates before meiosis I but not before meiosis II. This results in four haploid daughter cells.	biology
Organisms that lack both a nucleus and membrane-bound organelles are known as what, in general?	treasure	photosynthetic	lions and elephants	prokaryotic	Two of the three domains—Bacteria and Archaea—are prokaryotic, meaning that they lack both a nucleus and true membrane-bound organelles. However, they are now considered, on the basis of membrane structure and rRNA, to be as different from each other as they are from the third domain, the Eukarya. Prokaryotes were the first inhabitants on Earth, perhaps appearing approximately 3.9 billion years ago. Today they are ubiquitous—inhabiting the harshest environments on the planet, from boiling hot springs to permanently frozen environments in Antarctica, as well as more benign environments such as compost heaps, soils, ocean waters, and the guts of animals (including humans). The Eukarya include the familiar kingdoms of animals, plants, and fungi. They also include a diverse group of kingdoms formerly grouped together as protists.	biology
What happens to most of the energy in a trophic level as it passes to the next higher level?	cerebellum	it increases	it is transferred	it is lost		physics
What is the name for a specific amount of solute that can dissolve in a given amount of solvent?	concentration	humidity	viscosity	solubility	Solubility is a specific amount of solute that can dissolve in a given amount of solvent.	chemistry
What is freshwater below the earth's surface called?	precipitation	geyser	sediment	groundwater	Freshwater below Earth’s surface is called groundwater . The water infiltrates, or seeps down into, the ground from the surface. How does this happen? And where does the water go?.	physics
What forms when crystals precipitate out from a liquid?	an alkali metal	naphthalene	plasma sedimentary rocks	chemical sedimentary rocks	Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum.	chemistry
What do people build to protect areas from floods?	sewers	reinforced walls	when they form	dams	People protect areas that might flood with dams. In dire situations, they use sandbags ( Figure below ). Dams are usually very effective, but high water levels sometimes cause a dam to break. In that case, flooding can be catastrophic. Flood waters can also overflow a dam. People may line a river bank with levees to protect against floods. These are high walls that keep the stream within its banks during floods. Flood protection in one location sometimes causes problems elsewhere. For example, a levee in one location may just force the high water upstream or downstream. This will lead to flooding in a different location. Sometimes water gets so high that the river must be allowed to flood.	geography
What system of the body is responsible for ultimately ridding it of waste and excess water?	respiratory system	circulatory system	digestive system	excretory system	Toxic waste must be disposed of properly or there can be serious consequences. Now, your waste should not be as colorful or toxic as shown here (if it is, get yourself to a doctor as soon as possible), but it still needs to be removed from you. And that is the role of the excretory system. The excretory system gets rid of waste and excess water.	biology
What's it called when there's a sudden flow of mud?	k2	carbohydrate is synthesized	percent density	mudflow	A mudflow is the sudden flow of mud down a slope because of gravity. Mudflows occur where the soil is mostly clay. Like landslides, mudflows usually occur when the soil is wet. Wet clay forms very slippery mud that slides easily. Mudflows follow river channels, washing out bridges, trees, and homes that are in their path.	geography
Which zone is located below 200 meters from the surface?	mesopelagic	snow storm	observable zone	aphotic zone	Below 200 meters is the aphotic zone. There are no primary producers here because there isn’t enough sunlight for photosynthesis. However, the water may be rich in nutrients because of dead organisms drifting down from above. Organisms that live here may include bacteria, sponges, sea anemones, worms, sea stars, and fish.	geography

What causes the particles of medium to move parallel to the direction of the wave?

a gorge

disturbance theory

fluid waves

longitudinal waves

Longitudinal waves cause the particles of medium to move parallel to the direction of the wave.

physics

Which state of matter lacks a fixed volume, fixed shape, and consists of charged particles?

latin units

hydrogen giants

sedentary

ions

Plasma is a state of matter that lacks a fixed volume and a fixed shape and consists of charged particles called ions. Because it consists of charged particles, plasma can conduct electricity and respond to a magnetic field.

physics

What type of cell transmits electrical impulses in the nervous system?

epithelial

toxin cell

Large Cell

nerve cell

cell that transmits electrical impulses in the nervous system; commonly called nerve cell.

biology

What is the force pushing a rocket called?

ponds

electron microscope

terrible interference

thrust

Most halogens have a variety of important uses. A few are described in the Table below .

physics

In headwater streams, what plant process is mostly attributed to algae that are growing on rocks?

graduation

12-18 breaths

baby

photosynthesis

Abiotic features of rivers and streams vary along the length of the river or stream. Streams begin at a point of origin referred to as source water. The source water is usually cold, low in nutrients, and clear. The channel (the width of the river or stream) is narrower here than at any other place along the length of the river or stream. Headwater streams are of necessity at a higher elevation than the mouth of the river and often originate in regions with steep grades leading to higher flow rates than lower elevation stretches of the river. Faster-moving water and the short distance from its origin results in minimal silt levels in headwater streams; therefore, the water is clear. Photosynthesis here is mostly attributed to algae that are growing on rocks; the swift current inhibits the growth of phytoplankton. Photosynthesis may be further reduced by tree cover reaching over the narrow stream. This shading also keeps temperatures lower. An additional input of energy can come from leaves or other organic material that falls into a river or stream from the trees and other plants that border the water. When the leaves decompose, the organic material and nutrients in the leaves are returned to the water. The leaves also support a food chain of invertebrates that eat them and are in turn eaten by predatory invertebrates and fish. Plants and animals have adapted to this fast-moving water. For instance, leeches (phylum Annelida) have elongated bodies and suckers on both ends. These suckers attach to the substrate, keeping the leech anchored in place. In temperate regions, freshwater trout species (phylum Chordata) may be an important predator in these fast-moving and colder river and streams.

biology

What is the term that refers to stored chemical energy in organic matter or wastes?

pigments

codeine

sodium and solvent

biomass energy

The stored chemical energy in organic matter or wastes is called biomass energy. The organic matter may be trees or other plants, or it may be wastes from homes and industries. When biomass is burned, it produces thermal energy that can be used for heating homes, cooking, or generating electricity. Biomass—especially wood—is an important energy source in the poorer nations where most people can’t afford fossil fuels. However, burning biomass releases air pollution and contributes to global climate change. Biomass can be used to make ethanol, a fuel that is added to gasoline. Although ethanol releases less pollution than gasoline, large areas of land are needed to grow the plants needed to make it (see Figure below ). This reduces the amount of land available for food production.

chemistry

The process of photosynthesis ultimately gets powered by what kind of energy?

shallower

genetic drift

precipitates

light

biology

A binary molecular compound is a molecular compound that is composed of what?

four elements

two atoms

four atoms

two elements

A binary molecular compound is a molecular compound that is composed of two elements. In general, the elements that combine to form binary molecular compounds are both nonmetals. This contrasts with ionic compounds, which usually involve bonds between metal ions and nonmetal ions. Because ionic charges cannot be used to name these compounds or to write their formulas, a different naming system must be used for molecular compounds. Another difference between ionic and molecular compounds is that two nonmetal atoms will frequently combine with one another in a variety of ratios. For example, nitrogen and oxygen combine to make several binary compounds, including NO, NO 2 , and N 2 O. Obviously they can’t all be called nitrogen oxide! How would someone know which one you were talking about? Each of the three compounds has very different properties and reactivity. A system to distinguish between compounds such as these is necessary.

chemistry

Within the first 8 weeks of gestation, a developing embryo establishes the rudimentary structures of all of its organs and tissues from the ectoderm, mesoderm, and endoderm. this process is called what?

homeobox genes

ultraviolet rays

the chest cavity

organogenesis

Within the first 8 weeks of gestation, a developing embryo establishes the rudimentary structures of all of its organs and tissues from the ectoderm, mesoderm, and endoderm. This process is called organogenesis. Like the central nervous system, the heart also begins its development in the embryo as a tube-like structure, connected via capillaries to the chorionic villi. Cells of the primitive tube-shaped heart are capable of electrical conduction and contraction. The heart begins beating in the beginning of the fourth week, although it does not actually pump embryonic blood until a week later, when the oversized liver has begun producing red blood cells. (This is a temporary responsibility of the embryonic liver that the bone marrow will assume during fetal development. ) During weeks 4–5, the eye pits form, limb buds become apparent, and the rudiments of the pulmonary system are formed. During the sixth week, uncontrolled fetal limb movements begin to occur. The gastrointestinal system develops too rapidly for the embryonic abdomen to accommodate it, and the intestines temporarily loop into the umbilical cord. Paddle-shaped hands and feet develop fingers and toes by the process of apoptosis (programmed cell death), which causes the tissues between the fingers to disintegrate. By week 7, the facial structure is more complex and includes nostrils, outer ears, and lenses (Figure 28.15). By the eighth week, the head is nearly as large as the rest of the embryo’s body, and all major brain structures are in place. The external genitalia are apparent, but at this point, male and female embryos are indistinguishable. Bone begins to replace cartilage in the embryonic skeleton through the process of ossification. By the end of the embryonic period, the embryo is approximately 3 cm (1.2 in) from crown to rump and weighs approximately 8 g (0.25 oz).

biology

What goes through different larval stages?

intervertebral foramen

olivary tubules

mortality

crustaceans

Figure 28.41 All crustaceans go through different larval stages. Shown are (a) the nauplius larval stage of a tadpole shrimp, (b) the cypris larval stage of a barnacle, and (c) the zoea larval stage of a green crab. (credit a: modification of work by USGS; credit b: modification of work by Mª. Mingorance Rodríguez; credit c: modification of work by B. Kimmel based on original work by Ernst Haeckel).

biology

What is the major cause of chronic respiratory disease as well as cardiovascular disease and cancer?

mold

drinking

exercise

smoking

Smoking is the major cause of chronic respiratory disease as well as cardiovascular disease and cancer. Exposure to tobacco smoke by smoking or by breathing air that contains tobacco smoke is the leading cause of preventable death in the United States. Regular smokers die about 10 years earlier than nonsmokers do. The Centers for Disease Control and Prevention (CDC) describes tobacco use as "the single most important preventable risk to human health in developed countries and an important cause of [early] death worldwide. " Simply stated: Stopping smoking can prevent many respiratory diseases.

biology

Monotremes, marsupials, and placental mammals are subclasses of what?

reefs

digested

reptiles

mammals

Monotremes, marsupials, and placental mammals are subclasses of mammals. Almost all living mammals are placental mammals, which are divided into many orders.

biology

What type of mammal gives birth to young that need to develop further in the mother's pouch after birth?

Cleaning

humans

whales

marsupials

Marsupials give birth to a tiny, immature embryo. The embryo then continues to grow and develop in a pouch on the mother’s belly. This is less risky for the mother. However, the embryo is fragile, so it may be less likely to survive than the fetus of a placental mammal.

biology

What is the measure of how closely molecules are packed together?

the mass quadruples

healing magnet

convection insulators

density

Density is mass per unit volume. Density is a measure of how closely molecules are packed together. The closer together they are, the greater the density. Since air is a gas, the molecules can pack tightly or spread out.

physics

What is the leading cause of lung cancer?

hypha

feeding

cocoon stage

tobacco smoke

Tobacco smoke contains dozens of carcinogens, including nicotine and formaldehyde. Exposure to tobacco smoke is the leading cause of lung cancer.

biology

The golgi removes some sugar monomers and substitutes others, producing a large variety of what?

proteins

flow law

four atoms

carbohydrates

chemistry

Parenchymal, collenchymal, and sclerenchymal cells are associated with what types of living things?

fungi

primates

parasites

plants

Different types of plant cells include parenchymal, collenchymal, and sclerenchymal cells. The three types differ in structure and function.

biology

What is the name of the location in which a stream or river starts?

mouth

spring

shore

source

All streams and rivers have several features in common. These features are shown in ( Figure below ). The place where a stream or river starts is its source. The source might be a spring, where water flows out of the ground. Or the source might be water from melting snow on a mountain top. A single stream may have multiple sources. A stream or river probably ends when it flows into a body of water, such as a lake or an ocean. A stream ends at its mouth. As the water flows into the body of water, it slows down and drops the sediment it was carrying. The sediment may build up to form a delta.

geography

What disease occurs when cells in the breast grow out of control and form a tumor?

omniverous

adult breast growth

repolarization

breast cancer

Breast cancer is the most common type of cancer in females. It occurs when cells in the breast grow out of control and form a tumor. Breast cancer is rare in teens but becomes more common as females get older. Regular screening is recommended for most women starting around age 40. If found early, breast cancer usually can be cured with surgery.

biology

What process refers to the changes that occur in populations of living organisms over time?

variation

in the lymph

adaptation

evolution

The term evolution describes the changes that occur in populations of living organisms over time. Describing these changes does not address the origin of life. The two are commonly and mistakenly confused. Biological evolution likewise says nothing about cosmology, the Big Bang, or where the universe, galaxy, solar system, or Earth came from.

biology

Alkenes can react with what to form alcohols?

magnet

air

proteins

water

Alkenes can react with water to form alcohols.

chemistry

Wind blown sand contributes to what type of erosion?

immune system

modification

sedimentary

abrasion

Did you ever see workers sandblasting a building to clean it? Sand is blown onto the surface to scour away dirt and debris. Wind-blown sand has the same effect. It scours and polishes rocks and other surfaces. Wind-blown sand may carve rocks into interesting shapes. You can see an example in Figure below . This form of erosion is called abrasion. It occurs any time rough sediments are blown or dragged over surfaces. Can you think of other ways abrasion might occur?.

geography

Bases are ionic compounds consisting of hydroxide ions and a what?

sulfate

cinion

carbonate

cation

Bases are ionic compounds consisting of hydroxide ions and a cation. Naming and formula writing for bases follows the same guidelines as for other ionic compounds.

chemistry

What causes the menstrual cycle to be repeated?

ovaries

gravity

uteris

lack of fertilization

The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. It includes changes in the uterus as well as development of an egg and ovulation. If fertilization does not occur, menstruation occurs and the cycle repeats.

biology

What happens when turgid cells in a nonwoody tissue push against each other?

the tissues merge

wasp

the tissue melts

the tissue stiffens

biology

What is the waxy substance that epidermal cells secrete?

saliva

cellulose

bile

cuticle

Dermal tissue covers the outside of a plant in a single layer of cells called the epidermis. You can think of the epidermis as the plant’s skin. It mediates most of the interactions between a plant and its environment. Epidermal cells secrete a waxy substance called cuticle , which coats, waterproofs, and protects the above-ground parts of plants. Cuticle helps prevent water loss, abrasions, infections, and damage from toxins.

biology

What is the length of the route between two points?

velocity

pons

direction

distance

Distance is the length of the route between two points. The distance of a race, for example, is the length of the track between the starting and finishing lines. In a 100-meter sprint, that distance is 100 meters.

geography

According to the first law of thermodynamics, what can neither be created nor destroyed?

light

fuel

Leukemogenesis

energy

Chapter 46 1 Figure 46.8 According to the first law of thermodynamics, energy can neither be created nor destroyed. Eventually, all energy consumed by living systems is lost as heat or used for respiration, and the total energy output of the system must equal the energy that went into it. 3 Figure 46.17 C: Nitrification by bacteria converts nitrates (NO3−) to nitrites (NO2−). 4 D 6 B 8 A 10 D 12 D 14 B 16 A 18 A 20 C 21 Food webs show interacting groups of different species and their many interconnections with each other and the environment. Food chains are linear aspects of food webs that describe the succession of organisms consuming one another at defined trophic levels. Food webs are a more accurate representation of the structure and dynamics of an ecosystem. Food chains are easier to model and use for experimental studies. 23 Grazing food webs have a primary producer at their base, which is either a plant for terrestrial ecosystems or a phytoplankton for aquatic ecosystems. The producers pass their energy to the various trophic levels of consumers. At the base of detrital food webs are the decomposers, which pass this energy to a variety of other consumers. Detrital food webs are important for the health of many grazing food webs because they eliminate dead and decaying organic material, thus, clearing space for new organisms and removing potential causes of disease. By breaking down dead organic matter, decomposers also make mineral nutrients available to primary producers; this process is a vital link in nutrient cycling. 25 NPE measures the rate at which one trophic level can use and make biomass from what it attained in the previous level, taking into account respiration, defecation, and heat loss. Endotherms have high metabolism and generate a lot of body heat. Although this gives them advantages in their activity level in colder temperatures, these organisms are 10 times less efficient at harnessing the energy from the food they eat compared with cold-blooded animals, and thus have to eat more and more often. 27 Many factors can kill life in a lake or ocean, such as eutrophication by nutrient-rich surface runoff, oil spills, toxic waste spills, changes in climate, and the dumping of garbage into the ocean. Eutrophication is a result of nutrient-rich runoff from land using artificial fertilizers high in nitrogen and phosphorus. These nutrients cause the rapid and excessive growth of microorganisms, which deplete local dissolved oxygen and kill many fish and other aquatic organisms.

physics

What are the three primary pigment colors?

red, green, blue

red, white, blue

allele frequency

cyan, yellow, magenta

Pigments are substances that color materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. The primary pigment colors are cyan, yellow, and magenta. They can be combined to produce all other colors.

biology

How do organophostbate pesticides work?

inhibiting testosterone

inhibiting reticulum

inhibiting cryptosporidium

inhibiting acetylcholinesterase

biology

In the case of a light bulb, electricity is converted to light and what kind of energy?

chemical

rust

infrared waves

thermal

Most circuits have devices such as light bulbs that convert electric energy to other forms of energy. In the case of a light bulb, electricity is converted to light and thermal energy.

physics

Where in relation to the home, are levels of vocs found to be higher?

outdoors

niche

in Fields

indoors

The processes of evolution are fundamental to much of biology. Why do people have such a hard time understanding them?.

geography

Density and pressure of air decreases with what?

surface friction

temperature

30

altitude

Like density, the pressure of the air decreases with altitude. There is less air pressing down from above the higher up you go. Look at the bottle in Figure below . It was drained by a hiker at the top of a mountain. Then the hiker screwed the cap on the bottle and carried it down to sea level. At the lower altitude, air pressure crushed it. Can you explain why?.

physics

Energy is absorbed in the process of converting a liquid at its boiling point into a what?

neons

strongest surface area

plasma

gas

Energy is absorbed in the process of converting a liquid at its boiling point into a gas. As with the melting of a solid, the temperature of a boiling liquid remains constant and the input of energy goes into changing the state. The molar heat of vaporization of a substance is the heat absorbed by one mole of that substance as it is converted from a liquid to a gas. As a gas condenses to a liquid, heat is released. The molar heat of condensation of a substance is the heat released by one mole of that substance as it is converted from a gas to a liquid. Since vaporization and condensation of a given substance are the exact opposite processes, the numerical value of the molar heat of vaporization is the same as the numerical value of the molar heat of condensation, but opposite in sign. In other words, .

physics

Images in what type of mirror are reversed left and right but not reversed top and bottom?

convex

low and wide

virtual

plane mirror

Images in a plane mirror are reversed left and right but not reversed top and bottom.

physics

What do cells produce as they age?

oxidants

carcinogens

wrinkles

proto-oncogenes

biology

The body of the simplest sponges takes the shape of a cylinder with a large central cavity, called?

curve

land mass

belt

spongocoel

The body of the simplest sponges takes the shape of a cylinder with a large central cavity, the spongocoel. Water enters the spongocoel from numerous pores in the body wall. Water flows out through a large opening called the osculum (Figure 15.9). However, sponges exhibit a diversity of body forms, which vary in the size and branching of the spongocoel, the number of osculi, and where the cells that filter food from the water are located. Sponges consist of an outer layer of flattened cells and an inner layer of cells called choanocytes separated by a jellylike substance called mesohyl. The mesohyl contains embedded amoeboid cells that secrete tiny needles called spicules or protein fibers that help give the sponge its structural strength. The cell body of the choanocyte is embedded in mesohyl but protruding into the spongocoel is a mesh-like collar surrounding a single flagellum. The beating of flagella from all choanocytes moves water through the sponge. Food particles are trapped in mucus produced by the sieve-like collar of the choanocytes and are ingested by phagocytosis. This process is called intracellular digestion. Amoebocytes take up nutrients repackaged in food vacuoles of the choanocytes and deliver them to other cells within the sponge.

physics

Laid on dry land by reptiles, amniotic eggs have what that prevents them from drying out?

oil coating

tannin

double yolks

waterproof membranes

Loggerhead turtles spend most of their life in the ocean. Adult female loggerheads go ashore briefly to lay their eggs in the sand. Then they return to the water and leave the eggs to hatch on their own. Figure below shows baby loggerheads on a beach shortly after hatching. The baby turtles must make their way back to the water, hopefully without being snatched up by a predator. Loggerhead turtles are reptiles. Unlike amphibians, turtles and other reptiles can lay their eggs on dry land. That’s because they produce amniotic eggs. Amniotic eggs have waterproof membranes to prevent them from drying out.

biology

What three rs represent the steps that you personally can take to conserve our natural resources and minimize waste?

reduce, reuse, re-educate

rinse, reuse, recycle

remove, reduce, reuse

reduce, reuse, recycle

Reduce, reuse, and recycle. There are steps that you personally can take to conserve our natural resources and reduce waste. The waste that an individual creates is small in proportion to all the waste produced by society. Yet all small contributions, when added up, make a difference.

biology

What is the process that allows organisms with better traits to survive and produce?

comparative mutations

spontaneous mutation

Spermatogenesis

natural selection

Evolution occurs by natural selection, the process by which organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Evolution is due to differences in the survival and reproduction of individuals within a population.

biology

What is the term for a substance that increases the rate of a chemical reaction but is not changed or used up in the reaction?

a contribute

purification

repel

a catalyst

Some reactions need extra help to occur quickly. They need another substance, called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction but is not changed or used up in the reaction. The catalyst can go on to catalyze many more reactions.

chemistry

What type of compounds can form crystals?

molecular compounds

integral compounds

magnetic compounds

ionic compounds

Many compounds form molecules, but ionic compounds form crystals instead. A crystal consists of many alternating positive and negative ions bonded together in a matrix. Look at the crystal of sodium chloride (NaCl) in the Figure below . The sodium and chloride ions are attracted to each other because they are oppositely charged, so they form ionic bonds.

chemistry

In grazing, a predator partially eats but does not kill what?

vertical line system

time

pack

prey

In grazing , the predator eats part of the prey but does not usually kill it. You may have seen cows grazing on grass. The grass they eat grows back, so there is no real effect on the population. In the ocean, kelp (a type of seaweed) can regrow after being eaten by fish.

biology

Bone tissues include compact bone, spongy bone, bone marrow, and?

eutheria

slow aging

tourniquet

periosteum

Bone tissues include compact bone, spongy bone, bone marrow, and periosteum.

biology

What type of bacteria causes the disease called tuberculosis?

habitat chart

brain waves

blunt trauma

mycobacterium

Tuberculosis (TB) is a common and often deadly disease caused by a genus of bacterium called Mycobacterium . Tuberculosis most commonly attacks the lungs but can also affect other parts of the body. TB is a chronic disease, but most people who become infected do not develop the full disease. Symptoms include a cough, which usually contains mucus and coughing up blood.

biology

Studies have shown that not only does reproduction have a cost as far as how long male fruit flies live, but also fruit flies that have already mated several times have limited amounts of this?

chromosomes

dna

eggs

sperm

Energy Budgets, Reproductive Costs, and Sexual Selection in Drosophila Research into how animals allocate their energy resources for growth, maintenance, and reproduction has used a variety of experimental animal models. Some of this work has been done using the common fruit fly, Drosophila melanogaster. Studies have shown that not only does reproduction have a cost as far as how long male fruit flies live, but also fruit flies that have already mated several times have limited sperm remaining for reproduction. Fruit flies maximize their last chances at reproduction by selecting optimal mates. In a 1981 study, male fruit flies were placed in enclosures with either virgin or inseminated females. The males that mated with virgin females had shorter life spans than those in contact with the same number of inseminated females with which they were unable to mate. This effect occurred regardless of how large (indicative of their age) the males were. Thus, males that did not mate lived longer, allowing them more opportunities to find mates in the future. More recent studies, performed in 2006, show how males select the female with which they will mate and [3] how this is affected by previous matings (Figure 45.8). Males were allowed to select between smaller and larger females. Findings showed that larger females had greater fecundity, producing twice as many offspring per mating as the smaller females did. Males that had previously mated, and thus had lower supplies of sperm, were termed “resource-depleted,” while males that had not mated were termed “nonresource-depleted. ” The study showed that although non-resource-depleted males preferentially mated with larger females, this selection of partners was more pronounced in the resource-depleted males. Thus, males with depleted sperm supplies, which were limited in the number of times that they could mate before they replenished their sperm supply, selected larger, more fecund females, thus maximizing their chances for offspring. This study was one of the first to show that the physiological state of the male affected its mating behavior in a way that clearly maximizes its use of limited reproductive resources.

biology

What are the two most common causes of diseases?

atomical

dermal tissue

secondary consumers

bacteria and viruses

Today most people realize that microorganisms, such as bacteria or viruses, are the cause of disease. This concept is known as the germ theory of disease, one of the few scientific theories in the field of the life sciences. Although it seems obvious now, people did not always understand the cause of disease. How does a theory such as this become established?.

biology

Organic compounds are defined as covalently bonded compounds containing carbon, excluding carbonates and what else?

anticlines

a neutral one

molarity

oxides

At one time in history, it was thought that only living things were capable of synthesizing the carbon-containing compounds present in cells. For that reason, the term organic was applied to those compounds. Eventually it was proved that carbon-containing compounds could be synthesized from inorganic substances, but the term organic has remained. Currently, organic compounds are defined as covalently bonded compounds containing carbon, excluding carbonates and oxides. By this definition, compounds such as carbon dioxide (CO 2 ) and sodium carbonate (Na 2 CO 3 ) are considered to be inorganic. Organic chemistry is the study of all organic compounds.

chemistry

What drives the turbine in a thermonuclear reactor?

wind energy

magnets

heated oil

heated water or steam

Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. You can see how this might work in the Figure below . In the thermonuclear reactor, radiation from fusion is used to heat water and produce steam. The steam can then be used to turn a turbine and generate electricity.

physics

What is the term for physicians and scientists who research and develop vaccines and treat and study conditions ranging from allergies to aids?

virologists

gaseous chemicals

vaccinologists

immunologists

Immunologist The variations in peripheral proteins and carbohydrates that affect a cell’s recognition sites are of prime interest in immunology. These changes are taken into consideration in vaccine development. Many infectious diseases, such as smallpox, polio, diphtheria, and tetanus, were conquered by the use of vaccines. Immunologists are the physicians and scientists who research and develop vaccines, as well as treat and study allergies or other immune problems. Some immunologists study and treat autoimmune problems (diseases in which a person’s immune system attacks his or her own cells or tissues, such as lupus) and immunodeficiencies, whether acquired (such as acquired immunodeficiency syndrome, or AIDS) or hereditary (such as severe combined immunodeficiency, or SCID). Immunologists are called in to help treat organ transplantation patients, who must have their immune systems suppressed so that their bodies will not reject a transplanted organ. Some immunologists work to understand natural immunity and the effects of a person’s environment on it. Others work on questions about how the immune system affects diseases such as cancer. In the past, the importance of having a healthy immune system in preventing cancer was not at all understood. To work as an immunologist, a PhD or MD is required. In addition, immunologists undertake at least 2–3 years of training in an accredited program and must pass an examination given by the American Board of Allergy and Immunology. Immunologists must possess knowledge of the functions of the human body as they relate to issues beyond immunization, and knowledge of pharmacology and medical technology, such as medications, therapies, test materials, and surgical procedures.

biology

Where are temperatures the lowest?

below

over the oceans

at the equator

at the poles

At the poles, the Sun’s rays are least direct. Much of the area is covered with ice and snow, which reflect a lot of sunlight. Temperatures are lowest here.

geography

Protecting the surface of metal prevents what?

chronic exposure

extraction

instance point

corrosion

One way to prevent corrosion is to protect the surface of the metal. Covering the surface of the metal object with paint or oil will prevent corrosion by not allowing oxygen to contact it. Unfortunately, scratches in the paint or wearing off of the oil will allow the corrosion to begin. Corrosion-sensitive metals can also be coated with another metal that is resistant to corrosion. A “tin can” is actually made of iron coated with a thin layer of tin which protects the iron.

physics

What type of tissues are major barriers to the entry of pathogens into the body?

nasal

skin

vascular

mucosal

The Mucosal Immune Response Mucosal tissues are major barriers to the entry of pathogens into the body. The IgA (and sometimes IgM) antibodies in mucus and other secretions can bind to the pathogen, and in the cases of many viruses and bacteria, neutralize them. Neutralization is the process of coating a pathogen with antibodies, making it physically impossible for the pathogen to bind to receptors. Neutralization, which occurs in the blood, lymph, and other body fluids and secretions, protects the body constantly. Neutralizing antibodies are the basis for the disease protection offered by vaccines. Vaccinations for diseases that commonly enter the body via mucous membranes, such as influenza, are usually formulated to enhance IgA production. Immune responses in some mucosal tissues such as the Peyer’s patches (see Figure 21.11) in the small intestine take up particulate antigens by specialized cells known as microfold or M cells (Figure 21.27). These cells allow the body to sample potential pathogens from the intestinal lumen. Dendritic cells then take the antigen to the regional lymph nodes, where an immune response is mounted.

biology

Trash that gets into fresh and saltwater waterways is called what type of debris?

water

pollution

ocean

aquatic

Most protists consist of a single cell. Some are multicellular but they lack specialized cells.

geography

What is the term for genes that control the expression of other genes within specific regions of cells in the developing organism?

data genes

expression genes

dispersive

gap genes

Gap genes control the expression of other genes within specific regions of cells in the developing organism. This allows specific genes to be expressed in certain cells at the appropriate stage of development.

biology

In vertebrates, what tissue is a type of connective tissue that supports the entire body structure?

lingual tonsils

noninfectious disease

the environment

bone

Complex Tissue Structure As multicellular organisms, animals differ from plants and fungi because their cells don’t have cell walls, their cells may be embedded in an extracellular matrix (such as bone, skin, or connective tissue), and their cells have unique structures for intercellular communication (such as gap junctions). In addition, animals possess unique tissues, absent in fungi and plants, which allow coordination (nerve tissue) of motility (muscle tissue). Animals are also characterized by specialized connective tissues that provide structural support for cells and organs. This connective tissue constitutes the extracellular surroundings of cells and is made up of organic and inorganic materials. In vertebrates, bone tissue is a type of connective tissue that supports the entire body structure. The complex bodies and activities of vertebrates demand such supportive tissues. Epithelial tissues cover, line, protect, and secrete. Epithelial tissues include the epidermis of the integument, the lining of the digestive tract and trachea, and make up the ducts of the liver and glands of advanced animals. The animal kingdom is divided into Parazoa (sponges) and Eumetazoa (all other animals). As very simple animals, the organisms in group Parazoa (“beside animal”) do not contain true specialized tissues; although they do possess specialized cells that perform different functions, those cells are not organized into tissues. These organisms are considered animals since they lack the ability to make their own food. Animals with true tissues are in the group Eumetazoa (“true animals”). When we think of animals, we usually think of Eumetazoans, since most animals fall into this category. The different types of tissues in true animals are responsible for carrying out specific functions for the organism. This differentiation and specialization of tissues is part of what allows for such incredible animal diversity. For example, the evolution of nerve tissues and muscle tissues has resulted in animals’ unique ability to rapidly sense and respond to changes.

biology

Red blood cells don't have a nucleus. this allows them to do what?

heal faster

endosymbiosis

move faster

carry more oxygen

Red blood cells ( Figure below ) are made in the red marrow of long bones, rib bones, the skull, and vertebrae. Each red blood cell lives for only 120 days (about four months). After this time, they are destroyed in the liver and spleen. Mature red blood cells do not have a nucleus or other organelles. Lacking these components allows the cells to have more hemoglobin and carry more oxygen.

biology

The number of electron pairs that hold two atoms together is called?

dynamics

phenomena

filter

bond order

Summary Bond order is the number of electron pairs that hold two atoms together. Single bonds have a bond order of one, and multiple bonds with bond orders of two (a double bond) and three (a triple bond) are quite common. In closely related compounds with bonds between the same kinds of atoms, the bond with the highest bond order is both the shortest and the strongest. In bonds with the same bond order between different atoms, trends are observed that, with few exceptions, result in the strongest single bonds being formed between the smallest atoms. Tabulated values of average bond energies can be used to calculate the enthalpy change of many chemical reactions. If the bonds in the products are stronger than those in the reactants, the reaction is exothermic and vice versa. Saylor URL: http://www. saylor. org/books.

physics

What occurs when the immune system makes an inflammatory response to a harmless antigen?

myoglobin

antibodies

asthma attack

allergies

Allergies occur when the immune system makes an inflammatory response to a harmless antigen. An antigen that causes an allergy is called an allergen.

biology

What energy source, now making a comeback, has helped propel ships and pump water for many years?

solar energy

motile shell

fluorine

wind energy

The whirring blades of these wind turbines look stark against the darkening sky at sunset. The energy of the wind causes the blades to spin, and the energy of the spinning blades is used to generate electricity. People have been using wind for energy for centuries. Until about 200 years ago, for example, ships depended on wind to sail the oceans. And windmills have long been used to gather wind energy to pump water and do other useful work. Today, wind energy is making a comeback. Do you know why? What might be advantages of using the wind for energy? This chapter has the answers.

physics

What is it called when the nucleus of an atom splits into two smaller nuclei?

nuclear fusion

complex fission

flexible energy

nuclear fission

Nuclear fission is the splitting of the nucleus of an atom into two smaller nuclei. This releases a great deal of energy. Nuclear power plants use the energy from nuclear fission to generate electricity.

physics

The curie (ci) is one measure of the rate of what?

growth

spin

division

decay

The curie (Ci) is one measure of the rate of decay (named after Pierre and Marie Curie). One curie is equivalent to 3.7 × 10 10 disintegrations per second. Since this is obviously a large and unwieldy number, radiation is often expressed in millicuries or microcuries (still very large numbers). Another measure is the becquerel (Bq) , named after Henri Becquerel. The becquerel is defined as an activity of one disintegration/second. Both of these units are concerned with the disintegration rate of the radioactive isotope and give no indication of dosage to the target material.

physics

A unique type of organism is also known as what?

element

taxonomy

parasites

species

A species is a unique type of organism. Members of a species can interbreed and produce offspring that can breed (they are fertile). Organisms that are not in the same species cannot do this. Examples of species include humans, lions, and redwood trees. Can you name other examples?.

biology

Snakes use what anatomical structure to smell scents in the air?

zona pellucida

monocots

are not cells

forked tongue

Most reptiles have good eyesight and a keen sense of smell. Snakes smell scents in the air using their forked tongue (see Figure below ). This helps them locate prey. Some snakes have heat-sensing organs on their head that help them find endothermic prey, such as small mammals and birds. Staring into the Beautiful Cold-Blooded Eyes of Reptiles at http://www. environmentalgraffiti. com/news-reptile-eyes is a pictorial display of numerous reptile eyes.

biology

What chemical element helps forms strong bones and teeth in humans?

magnesium

iron

potassium

calcium

Minerals are chemical elements that are essential for body processes. They include calcium, which helps form strong bones and teeth, and potassium, which is needed for normal nerve and muscle function. Good sources of minerals include leafy, green vegetables, whole grains, milk, and meats.

chemistry

The limit to how much solute will dissolve in a given amount of solvent is called what?

strength

density

potency

solubility

Solubility There is usually a limit to how much solute will dissolve in a given amount of solvent. This limit is called the solubility of the solute. Some solutes have a very small solubility, while other solutes are soluble in all proportions. Table 9.2 "Solubilities of Various Solutes in Water at 25°C (Except as Noted)" lists the solubilities of various solutes in water. Solubilities vary with temperature, so Table 9.2 "Solubilities of Various Solutes in Water at 25°C (Except as Noted)" includes the temperature at which the solubility was determined. Table 9.2 Solubilities of Various Solutes in Water at 25°C (Except as Noted).

chemistry

What occurs when hot magma transforms rock that it contacts?

changing metamorphism

existence metamorphism

form metamorphism

contact metamorphism

Contact metamorphism occurs when hot magma transforms rock that it contacts.

physics

What term refers to entities, events or powers regarded as being beyond nature, and cannot be explained by scientific means?

natural

hypothetical

Distinct Chamber Therapy

supernatural

Science is based on the analysis of observations made either through our senses or by using special equipment. Science therefore cannot explain anything about the natural world that is beyond what is observable. The term supernatural refers to entities, events, or powers regarded as being beyond nature, in that such things cannot be explained by scientific means. They are not measurable or observable in the same way the natural world is, and are therefore considered to be outside the realm of scientific examination.

physics

What causes an elastic force in springs?

windchill

velocity

triangles

stretching or compressing

Springs like the ones in Figure below also have elastic force when they are stretched or compressed. And like stretchy materials, they return to their original shape when the stretching or compressing force is released. Because of these properties, springs are used in scales to measure weight. They also cushion the ride in a car and provide springy support beneath a mattress. Can you think of other uses of springs?.

physics

What effect is responsible for flight paths looking curved?

it vibrates

salt water

antioxidants

coriolis effect

Zappy's. Flight paths look curved due to the Coriolis effect . CC BY-NC 3.0.

physics

Wetlands are environments in which the soil is either permanently or periodically saturated with what?

spores

downwelling

oceanic pillar

water

Wetlands Wetlands are environments in which the soil is either permanently or periodically saturated with water. Wetlands are different from lakes and ponds because wetlands exhibit a near continuous cover of emergent vegetation. Emergent vegetation consists of wetland plants that are rooted in the soil but have portions of leaves, stems, and flowers extending above the water’s surface. There are several types of wetlands including marshes, swamps, bogs, mudflats, and salt marshes (Figure 20.33).

geography

When the ground absorbs the water and it settles below the surface it is called what?

precipitation

wastewater

glacier

groundwater

physics

Some metabolic pathways release what by breaking down complex molecules to simpler compounds?

water

renal artery

hydrogen

energy

biology

What is the smallest portion of a crystal lattice?

further apart

updraft

outer electrons

unit cell

A unit cell is the smallest portion of a crystal lattice that shows the three-dimensional pattern of the entire crystal. A crystal can be thought of as the same unit cell repeated over and over in three dimensions. The Figure below illustrates the relationship of a unit cell to the entire crystal lattice.

physics

What is one major cause of skin cancer?

infrared light

fight

aquatic green algae

ultraviolet light

The most important way to keep your skin healthy is to protect it from ultraviolet light. Over-exposure to ultraviolet light can cause skin cancer. Keeping the skin clean can help prevent acne.

biology

Which important decomposers are known to live just about anywhere on earth?

sporozoans

protazoas

viruses

archeans

Archaeans are now known to live just about everywhere on Earth. They are important decomposers. Many live in close relationships with other organisms. They are generally harmless and often beneficial.

biology

In the scientific method, what is the initial, unproven explanation for why something is occurring?

peaks

concepts

plasmid

hypothesis

The scientific method is not a step by step, linear process. It is a way of learning about the world through the application of knowledge. Scientists must be able to have an idea of what the answer to an investigation should be. In order for scientists to make educated guesses about the answers, they will base their guesses on previous knowledge, with the notion of extending that knowledge. Scientists will often make an observation and then form a hypothesis to explain why a phenomenon occurred. They use all of their knowledge and a bit of imagination in their journey of discovery.

physics

What is the name of an element with a different number of neutrons?

visible light

micro microscopes

reaction

isotope

All atoms of the same element have the same number of protons, but some may have different numbers of neutrons. For example, all carbon atoms have six protons, and most have six neutrons as well. But some carbon atoms have seven or eight neutrons instead of the usual six. Atoms of the same element that differ in their numbers of neutrons are called isotopes . Many isotopes occur naturally. Usually one or two isotopes of an element are the most stable and common. Different isotopes of an element generally have the same physical and chemical properties. That’s because they have the same numbers of protons and electrons. For a video explanation of isotopes, go to this URL:.

physics

Nitrogen and sulfur oxides form what type of rain?

heavy rain

common rain

toxic rain

acid rain

Both nitrogen and sulfur oxides are toxic to humans. These compounds can cause lung diseases or make them worse. Nitrogen and sulfur oxides form acid rain, which is described in the next concept.

chemistry

Polyester fabric's resistance to wrinkling comes from the cross-linking of what?

wool strands

thickness and gravity

velocity strands

polymer strands

PET is used in tires, photographic film, food packaging, and clothing. Polyester fabric is used in permanent-press clothing. Its resistance to wrinkling comes from the cross-linking of the polymer strands.

physics

What term refers to the sequence of community and ecosystem changes after a disturbance?

physiological succession

progressions

an omnivore

ecological succession

biology

What is the network of fibers that organizes structures and activities in the cell called?

DNA

enzymes

cytoplasm

cytoskeleton

6.6 The cytoskeleton is a network of fibers that organizes structures and activities in the cell.

biology

Decreasing the volume of a gas and keeping everything else the same will cause its pressure to change in what way?

existence and deduction

orbital state

estradiol

increase

When gas molecules bump into things, it creates pressure. Pressure is greater when gas molecules occupy a smaller space, because greater crowding results in more collisions. This explains why decreasing the volume of a gas increases its pressure.

physics

What evolutionary strategy enables substantial activity during sleep for some animals?

decay

pistills

cenozoic era

adaptation

biology

The cells of the blastocyst form an inner cell mass called the what?

xerophyte

blastocyst

chloroplast

embryoblast

The cells of the blastocyst form an inner cell mass and an outer cell layer, as shown in Figure below . The inner cell mass is called the embryoblast. These cells will soon develop into an embryo. The outer cell layer is called the trophoblast. These cells will develop into other structures needed to support and nourish the embryo.

biology

How do all musical instruments create sound?

conduction

primary pollutant

stimulation

vibration

All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air.

physics

What system disorders include kidney stones, kidney failure, and urinary tract infections?

renal system

nervous system

digestive system

urinary system

Disorders of the urinary system include kidney stones, kidney failure, and urinary tract infections.

biology

What type of respiration has the advantage of releasing more energy?

elastic

kinetic

adaptatioins

aerobic

A major advantage of aerobic respiration is the amount of energy it releases. Without oxygen, organisms can split glucose into just two molecules of pyruvate. This releases only enough energy to make two ATP molecules. With oxygen, organisms can break down glucose all the way to carbon dioxide. This releases enough energy to produce up to 38 ATP molecules. Thus, aerobic respiration releases much more energy than anaerobic respiration.

biology

Major climate types are based on what two things?

always

to horde the water

compressed layer

temperature & precipitation

Major climate types are based on temperature and precipitation. These two factors determine what types of plants can grow in an area. Animals and other living things depend on plants. So each climate is associated with certain types of living things. A major type of climate and its living things make up a biome . As you read about the major climate types below, find them on the map in Figure above .

geography

When amino acids bind together, they form a long chain called what, which is an essential component of protein?

Builds a crust

destroy the membrane

weak bonds

polypeptide

When amino acids bind together, they form a long chain called a polypeptide . A protein consists of one or more polypeptide chains. A protein may have up to four levels of structure. The lowest level, a protein’s primary structure, is its sequence of amino acids. Higher levels of protein structure are described in Figure below . The complex structures of different proteins give them unique properties, which they need to carry out their various jobs in living organisms. You can learn more about protein structure by watching the animation at the following link: http://www. stolaf. edu/people/giannini/flashanimat/proteins/protein%20structure. swf .

chemistry

What type of cells does meiosis produce?

mutated cells

younger adults

diploid daughter cells

haploid daughter cells

Meiosis is a special type of cell division. It produces haploid daughter cells. It occurs when an organism makes gametes. Meiosis is basically mitosis times two. The original diploid cell divides twice. The first time is called meiosis I. The second time is called meiosis II. However, the DNA replicates only once. It replicates before meiosis I but not before meiosis II. This results in four haploid daughter cells.

biology

Organisms that lack both a nucleus and membrane-bound organelles are known as what, in general?

treasure

photosynthetic

lions and elephants

prokaryotic

Two of the three domains—Bacteria and Archaea—are prokaryotic, meaning that they lack both a nucleus and true membrane-bound organelles. However, they are now considered, on the basis of membrane structure and rRNA, to be as different from each other as they are from the third domain, the Eukarya. Prokaryotes were the first inhabitants on Earth, perhaps appearing approximately 3.9 billion years ago. Today they are ubiquitous—inhabiting the harshest environments on the planet, from boiling hot springs to permanently frozen environments in Antarctica, as well as more benign environments such as compost heaps, soils, ocean waters, and the guts of animals (including humans). The Eukarya include the familiar kingdoms of animals, plants, and fungi. They also include a diverse group of kingdoms formerly grouped together as protists.

biology

What happens to most of the energy in a trophic level as it passes to the next higher level?

cerebellum

it increases

it is transferred

it is lost

physics

What is the name for a specific amount of solute that can dissolve in a given amount of solvent?

concentration

humidity

viscosity

solubility

Solubility is a specific amount of solute that can dissolve in a given amount of solvent.

chemistry

What is freshwater below the earth's surface called?

precipitation

geyser

sediment

groundwater

Freshwater below Earth’s surface is called groundwater . The water infiltrates, or seeps down into, the ground from the surface. How does this happen? And where does the water go?.

physics

What forms when crystals precipitate out from a liquid?

an alkali metal

naphthalene

plasma sedimentary rocks

chemical sedimentary rocks

Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum.

chemistry

What do people build to protect areas from floods?

sewers

reinforced walls

when they form

dams

People protect areas that might flood with dams. In dire situations, they use sandbags ( Figure below ). Dams are usually very effective, but high water levels sometimes cause a dam to break. In that case, flooding can be catastrophic. Flood waters can also overflow a dam. People may line a river bank with levees to protect against floods. These are high walls that keep the stream within its banks during floods. Flood protection in one location sometimes causes problems elsewhere. For example, a levee in one location may just force the high water upstream or downstream. This will lead to flooding in a different location. Sometimes water gets so high that the river must be allowed to flood.

geography

What system of the body is responsible for ultimately ridding it of waste and excess water?

respiratory system

circulatory system

digestive system

excretory system

Toxic waste must be disposed of properly or there can be serious consequences. Now, your waste should not be as colorful or toxic as shown here (if it is, get yourself to a doctor as soon as possible), but it still needs to be removed from you. And that is the role of the excretory system. The excretory system gets rid of waste and excess water.

biology

What's it called when there's a sudden flow of mud?

k2

carbohydrate is synthesized

percent density

mudflow

A mudflow is the sudden flow of mud down a slope because of gravity. Mudflows occur where the soil is mostly clay. Like landslides, mudflows usually occur when the soil is wet. Wet clay forms very slippery mud that slides easily. Mudflows follow river channels, washing out bridges, trees, and homes that are in their path.

geography

Which zone is located below 200 meters from the surface?

mesopelagic

snow storm

observable zone

aphotic zone

Below 200 meters is the aphotic zone. There are no primary producers here because there isn’t enough sunlight for photosynthesis. However, the water may be rich in nutrients because of dead organisms drifting down from above. Organisms that live here may include bacteria, sponges, sea anemones, worms, sea stars, and fish.

geography