questions stringlengths 37 1.22k | reasoning stringlengths 0 3.56k ⌀ | answers stringlengths 4 138 |
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Magnetism is due to the movement of what within atoms?
Here are the choices:
A. electrons
B. protons
C. neutrons
D. magnetrons | Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the electrons orbiting the nuclei of the atoms are arranged in such a way that the materials have no magnetic properties. Also, in most types of matter, the north and south poles of atoms point in all different directions, so overall the matter is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. | A: electrons. |
Ground subsidence is a consequences of the overuse of what?
Here are the choices:
A. chemicals
B. topsoil
C. groundwater
D. plants | Ground subsidence is a consequences of groundwater overuse. | C: groundwater. |
What organ do most fish have that is used to detect movement and vibration in the surrounding water?
Here are the choices:
A. eye
B. operculum
C. nares
D. lateral line | Sharks have well-developed sense organs that aid them in locating prey, including a keen sense of smell and electroreception, with the latter perhaps the most sensitive of any animal. Organs called ampullae of Lorenzini allow sharks to detect the electromagnetic fields that are produced by all living things, including their prey. Electroreception has only been observed in aquatic or amphibious animals. Sharks, together with most fishes and aquatic and larval amphibians, also have a sense organ called the lateral line, which is used to detect movement and vibration in the surrounding water, and is often considered homologous to “hearing” in terrestrial vertebrates. The lateral line is visible as a darker stripe that runs along the length of a fish’s body. Sharks reproduce sexually, and eggs are fertilized internally. Most species are ovoviviparous: The fertilized egg is retained in the oviduct of the mother’s body and the embryo is nourished by the egg yolk. The eggs hatch in the uterus, and young are born alive and fully functional. Some species of sharks are oviparous: They lay eggs that hatch outside of the mother’s body. Embryos are protected by a shark egg case or “mermaid’s purse” (Figure 29.12) that has the consistency of leather. The shark egg case has tentacles that snag in seaweed and give the newborn shark cover. A few species of sharks are viviparous: The young develop within the mother’s body and she gives live birth. | D: lateral line. |
Excretion is the process of removing excess water and wastes from the body. what are the main organs of excretion?
Here are the choices:
A. eyes
B. kidneys
C. lungs
D. brains | Excretion is the process of removing wastes and excess water from the body. It is one of the major ways the body maintains homeostasis. Although the kidneys are the main organs of excretion, several other organs also excrete wastes. They include the large intestine, liver, skin, and lungs. All of these organs of excretion, along with the kidneys, make up the excretory system . This lesson focuses on the role of the kidneys in excretion. The roles of the other excretory organs are summarized below:. | B: kidneys. |
What is caused by the same virus that causes chicken pox?
Here are the choices:
A. blisters
B. mumps
C. boils
D. shingles | Preston Hunt. Shingles is caused by the same virus that causes chicken pox . CC BY 3.0. | D: shingles. |
Amniotes are animals that produce eggs with membranes possessing what property, which allowed them to lay eggs on land?
Here are the choices:
A. hard
B. absorbent
C. waterproof
D. heavy | The first vertebrates to live fully on land were amniotes. Amniotes are animals that produce eggs with waterproof membranes. The membranes let gases but not water pass through. They allow embryos to breathe without drying out. Amniotic eggs were the first eggs that could be laid on land. The earliest amniotes evolved about 350 million years ago. Amniotes would eventually evolve into modern reptiles, mammals, and birds. | C: waterproof. |
When water particles become hot enough to overcome the force of attraction between them, what happens to the water?
Here are the choices:
A. it freezes
B. it boils
C. it evaporates
D. it pools | If water gets hot enough, it starts to boil. Bubbles of water vapor form in boiling water. This happens as particles of liquid water gain enough energy to completely overcome the force of attraction between them and change to the gaseous state. The bubbles rise through the water and escape from the pot as steam. | B: it boils. |
In mammals, what layer protects the egg?
Here are the choices:
A. Germinal Disc
B. Albumen
C. zona pellucida
D. Choloza | Early Embryonic Development Fertilization is the process in which gametes (an egg and sperm) fuse to form a zygote (Figure 18.8). To ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. In mammals, a layer called the zona pellucida protects the egg. At the tip of the head of a sperm cell is a structure like a lysosome called the acrosome, which contains enzymes. When a sperm binds to the zona pellucida, a series of events, called the acrosomal reactions, take place. These reactions, involving enzymes from the acrosome, allow the sperm plasma membrane to fuse with the egg plasma membrane and permit the sperm nucleus to transfer into the ovum. The nuclear membranes of the egg and sperm break down and the two haploid nuclei fuse to form a diploid nucleus or genome. | C: zona pellucida. |
After infecting a host, what inactive state do some viruses enter?
Here are the choices:
A. latency
B. potency
C. immunity
D. hibernation | A: latency. | |
Changes in the number of what can lead to disorders like down syndrome?
Here are the choices:
A. dna
B. genes
C. prokaryotes
D. chromosomes | Changes in chromosome number can lead to disorders like Down syndrome. | D: chromosomes. |
What are centrioles made from?
Here are the choices:
A. short microtubules
B. carbon
C. short particles
D. short filaments | Centrioles are made of short microtubules and are very important in cell division. | A: short microtubules. |
What of most species are resistant cells that can survive harsh conditions?
Here are the choices:
A. subtypes
B. gonads
C. phenotypes
D. zygotes | D: zygotes. | |
Animals can not produce their own food making them _________.
Here are the choices:
A. autotrophs
B. omnivores
C. photoreliant
D. heterotrophs | Animals are a kingdom of multicellular eukaryotes. They cannot make their own food. Instead, they get nutrients by eating other living things. Therefore, animals are heterotrophs . | D: heterotrophs. |
In the stomach, which material's arrival triggers churning and the release of gastric juices?
Here are the choices:
A. bile
B. acid
C. hair
D. food | D: food. | |
What is the term for seed plants?
Here are the choices:
A. proteins
B. sporozoans
C. spermatophytes
D. germospores | Most vascular plants are seed plants, or spermatophytes. They reproduce with seeds and pollen. Some modern seed plants are gymnosperms that produce seeds in cones. | C: spermatophytes. |
Cnidarians have a simple digestive system with a single opening surrounded by what type of structures, which are used to capture prey?
Here are the choices:
A. antennae
B. tentacles
C. claws
D. spines | The body of a cnidarian consists of two cell layers, ectoderm and endoderm. The cells surround a digestive cavity called the coelenteron (see Figure below ). Cnidarians have a simple digestive system. The single opening is surrounded by tentacles, which are used to capture prey. The tentacles are covered with nematocyst cells. Digestion takes place in the coelenteron. Nutrients are absorbed and gases exchanged through the cells lining this cavity. Fluid in the coelenteron creates a hydrostatic skeleton. | B: tentacles. |
What is the state of matter that resembles a gas, but is made of ions, giving it different properties than a typical gas?
Here are the choices:
A. plasma
B. vapor
C. gamma
D. acid | Plasma is a state of matter that resembles a gas but has certain properties that gases do not have. Like a gas, plasma consists of particles of matter than can pull apart and spread out, so it lacks a fixed volume and a fixed shape. Unlike a gas, plasma can conduct electricity and respond to a magnetic field. That’s because plasma consists of electrically charged particles called ions, instead of uncharged particles such as atoms or molecules. This gives plasma other interesting properties as well. For example, plasma glows with colored light when electricity passes through it. You can learn more about plasma at this URL: http://www. youtube. com/watch?v=VkeSI_B5Ljc. | A: plasma. |
Natural selection for what type of trait changes the distribution of phenotypes?
Here are the choices:
A. maladaptive trait
B. major trait
C. parent trait
D. polygenic trait | Natural selection for a polygenic trait changes the distribution of phenotypes. It may have a stabilizing, directional, or disruptive effect on the phenotype distribution. | D: polygenic trait. |
Systemic veins return blood low in what to the right atrium?
Here are the choices:
A. oxygen
B. nutrients
C. nitrogen
D. dioxide | Overview of Systemic Veins Systemic veins return blood to the right atrium. Since the blood has already passed through the systemic capillaries, it will be relatively low in oxygen concentration. In many cases, there will be veins draining organs and regions of the body with the same name as the arteries that supplied these regions and the two often parallel one another. This is often described as a “complementary” pattern. However, there is a great deal more variability in the venous circulation than normally occurs in the arteries. For the sake of brevity and clarity, this text will discuss only the most commonly encountered patterns. However, keep this variation in mind when you move from the classroom to clinical practice. In both the neck and limb regions, there are often both superficial and deeper levels of veins. The deeper veins generally correspond to the complementary arteries. The superficial veins do not normally have direct arterial counterparts, but in addition to returning blood, they also make contributions to the maintenance of body temperature. When the ambient temperature is warm, more blood is diverted to the superficial veins where heat can be more easily dissipated to the environment. In colder weather, there is more constriction of the superficial veins and blood is diverted deeper where the body can retain more of the heat. The “Voyage of Discovery” analogy and stick drawings mentioned earlier remain valid techniques for the study of systemic veins, but veins present a more difficult challenge because there are numerous anastomoses and multiple branches. It is like following a river with many tributaries and channels, several of which interconnect. Tracing blood flow through arteries follows the current in the direction of blood flow, so that we move from the heart through the large arteries and into the smaller arteries to the capillaries. From the capillaries, we move into the smallest veins and follow the direction of blood flow into larger veins and back to the heart. Figure 20.35 outlines the path of the major systemic veins. | A: oxygen. |
The three long muscles on the back of the knee are part of which group?
Here are the choices:
A. synovial joint
B. hamstring group
C. adductors
D. patella | of the proximal tibia. This versatile muscle flexes the leg at the knee and flexes, abducts, and laterally rotates the leg at the hip. This muscle allows us to sit cross-legged. The posterior compartment of the thigh includes muscles that flex the leg and extend the thigh. The three long muscles on the back of the knee are the hamstring group, which flexes the knee. These are the biceps femoris, semitendinosus, and semimembranosus. The tendons of these muscles form the popliteal fossa, the diamond-shaped space at the back of the knee. | B: hamstring group. |
What shapes, supports, and protects the cell?
Here are the choices:
A. the chloroplast
B. the mesothelium
C. the cell wall
D. the epithelium | The cell wall is located outside the cell membrane. It consists mainly of cellulose and may also contain lignin , which makes it more rigid. The cell wall shapes, supports, and protects the cell. It prevents the cell from absorbing too much water and bursting. It also keeps large, damaging molecules out of the cell. | C: the cell wall. |
What process, which results because of great pressure at the center of a star, causes stars to shine?
Here are the choices:
A. electric fusion
B. nuclear fusion
C. gravitational pull
D. energy fusion | Stars shine because of nuclear fusion. Fusion reactions in the Sun's core keep our nearest star burning. Stars are made mostly of hydrogen and helium. Both are very lightweight gases. A star contains so much hydrogen and helium that the weight of these gases is enormous. The pressure at the center of a star is great enough to heat the gases. This causes nuclear fusion reactions. | B: nuclear fusion. |
What do we call the formation of a gas from a liquid at temperatures below the boiling point?
Here are the choices:
A. steaming
B. melting
C. evaporation
D. pulverization | There are some properties that all liquids have. The liquid that we are most familiar with is probably water, and it has these properties. Other liquids have them as well, which is something to keep in mind. All liquids have a certain portion of their particles having enough energy to enter the gas phase, and if these particles are at the surface of the liquid, they do so ( - ball-ch10_s03_f01). The formation of a gas from a liquid at temperatures below the boiling point is called evaporation. At these temperatures, the material in the gas phase is called vapor, rather than gas; the term gas is reserved for when the gas phase is the stable phase. Figure 10.5 Evaporation. | C: evaporation. |
What is a sugar that is found in fruits?
Here are the choices:
A. fructose
B. sucrose
C. glucose
D. ethanol | In the Figure below , you can see structural formulas for glucose and two other sugars, named fructose and sucrose. Fructose is a sugar that is found in fruits. It is an isomer of glucose. Isomers are compounds that have the same atoms but different arrangements of atoms. Do you see how the atoms are arranged differently in fructose than in glucose? You’re probably most familiar with the sugar sucrose, because sucrose is table sugar. It’s the sugar that you spoon onto your cereal or into your iced tea. | A: fructose. |
What are unsaturated hydrocarbons with at least one triple bond between carbon atoms?
Here are the choices:
A. amines
B. lipids
C. alkynes
D. ketones | Alkynes are unsaturated hydrocarbons with at least one triple bond between carbon atoms. | C: alkynes. |
Are ecotones wide or narrow?
Here are the choices:
A. narrow
B. wide
C. can be both
D. somewhere in between | C: can be both. | |
Which infection of multicellular eukaryotes is usually limited to particular tissues?
Here are the choices:
A. viral
B. parasites
C. digestive
D. bacterial | A: viral. | |
What is the term for the breakdown of unstable isotopes into stable elements?
Here are the choices:
A. secondary decay
B. radioactive decay
C. isotopic decay
D. radioactive decrease | Radioactive decay is the breakdown of unstable isotopes into stable elements. For example, carbon-14 is an unstable isotope of carbon that decays to the stable element nitrogen-14. The rate of decay of an isotope is measured in half-lives. A half-life is the time it takes for half a given amount of an isotope to decay. | B: radioactive decay. |
What are the light wavelengths that the human eye can detect called?
Here are the choices:
A. visible light
B. apparent light
C. ultraviolet light
D. infrared light | Describe hotspots and the volcanic activity they create. | A: visible light. |
Most of the energy used by living things comes either directly or indirectly from what?
Here are the choices:
A. the sun
B. the moon
C. plants
D. the soil | Most of the energy used by living things comes either directly or indirectly from the sun. That’s because sunlight provides the energy for photosynthesis. This is the process in which plants and certain other organisms synthesize glucose (C 6 H 12 O 6 ). The process uses carbon dioxide and water and also produces oxygen. The overall chemical equation for photosynthesis is:. | A: the sun. |
Population growth is determined by rates of birth, death, immigration, and what else?
Here are the choices:
A. exploitation
B. emigration
C. excitation
D. relaxation | Population growth is determined by rates of birth, death, immigration, and emigration. | B: emigration. |
What works by selecting for alleles that confer beneficial traits or behaviors, while selecting against those for deleterious qualities?
Here are the choices:
A. natural selection
B. artificial selection
C. characteristic selection
D. same selection | 19.2 Population Genetics Both genetic and environmental factors can cause phenotypic variation in a population. Different alleles can confer different phenotypes, and different environments can also cause individuals to look or act differently. Only those differences encoded in an individual’s genes, however, can be passed to its offspring and, thus, be a target of natural selection. Natural selection works by selecting for alleles that confer beneficial traits or behaviors, while selecting against those for deleterious qualities. Genetic drift stems from the chance occurrence that some individuals in the germ line have more offspring than others. When individuals leave or join the population, allele frequencies can change as a result of gene flow. Mutations to an individual’s DNA may introduce new variation into a population. Allele frequencies can also be altered when individuals do not randomly mate with others in the group. | A: natural selection. |
Paint keeps oxygen and water from coming into direct contact with the metal, which prevents what?
Here are the choices:
A. heat
B. corrosion
C. filtration
D. evaporation | Paint keeps oxygen and water from coming into direct contact with the metal, which prevents corrosion. Paint is more necessary because salt is an electrolyte that increases the conductivity of water and facilitates the flow of electric current between anodic and cathodic sites. | B: corrosion. |
What type of electrons do all group 14 elements have four of?
Here are the choices:
A. shell
B. internal
C. valence
D. second layer | Group 14 is called the carbon group. Carbon (C) is a nonmetal. The next two elements are metalloids, and the final two are metals. All the elements in the carbon group have four valence electrons. They are not very reactive. All are solids at room temperature. | C: valence. |
List the three major types of blood vessels.
Here are the choices:
A. vessels, tubes, veins
B. arteries,capillaries, veins
C. veins, capillaries, vessels
D. vessels, arteries, capillaries | List and describe the three major types of blood vessels. | B: arteries,capillaries, veins. |
Acetone is the simplest type of what organic compound that involves a carbonyl in which the carbon atom makes single bonds with two other carbon atoms?
Here are the choices:
A. ketone
B. protein
C. anion
D. enzyme | A ketone involves a carbonyl in which the carbon atom makes single bonds with two other carbon atoms. Ketones undergo most of the same reactions as aldehydes, but they tend to be slightly less reactive. The simplest ketone is acetone, in which the carbonyl carbon is bonded to two CH 3 groups. This ketone is commonly used to remove fingernail polish and serves as an industrial solvent. Methyl ethyl ketone is used as a paint stripper and a solvent. Ketones are also used in the production of various polymers, either as a building block or as a solvent. | A: ketone. |
What term is used to describe birds that hunt, eat mammals, and other birds?
Here are the choices:
A. raptors
B. predators
C. consumers
D. warriors | Raptors such as hawks and owls are carnivores. They hunt and eat mammals and other birds. Vultures are scavengers. They eat the remains of dead animals, such as roadkill. Aquatic birds generally eat fish or water plants. Perching birds may eat insects, fruit, honey, or nectar. Many fruit-eating birds play a key role in seed dispersal, and some nectar-feeding birds are important pollinators. | A: raptors. |
What do you call a compound that contains both an amino group and a carboxyl group in the same molecule?
Here are the choices:
A. amino acid
B. carbolic acid
C. compound acid
D. catalyst | An amino acid is a compound that contains both an amino group (−NH 2 ) and a carboxyl group (−COOH) in the same molecule. While any number of amino acids can possibly be imagined, biochemists generally reserve the term for a group of 20 amino acids which are formed and used by living organisms. The Figure below shows the general structure of an amino acid. | A: amino acid. |
What system consists of structures that produce eggs, secrete female sex hormones, and ultimately enable birth of a fetus?
Here are the choices:
A. female hormone system
B. female reproductive system
C. female uterus system
D. male reproductive system | The female reproductive system consists of structures that produce eggs and secrete female sex hormones. They also provide a site for fertilization and enable the development and birth of a fetus. | B: female reproductive system. |
The medieval catapult has a heavy ballast on one end and what on the other end?
Here are the choices:
A. propellant
B. pivot
C. fragment
D. projectile | D: projectile. | |
What period starts after the baby is born, and the placenta is expelled from the body?
Here are the choices:
A. postpartum
B. postfetal
C. traumatic
D. fetal | Afterbirth The delivery of the placenta and associated membranes, commonly referred to as the afterbirth, marks the final stage of childbirth. After expulsion of the newborn, the myometrium continues to contract. This movement shears the placenta from the back of the uterine wall. It is then easily delivered through the vagina. Continued uterine contractions then reduce blood loss from the site of the placenta. Delivery of the placenta marks the beginning of the postpartum period—the period of approximately 6 weeks immediately following childbirth during which the mother’s body gradually returns to a nonpregnant state. If the placenta does not birth spontaneously within approximately 30 minutes, it is considered retained, and the obstetrician may attempt manual removal. If this is not successful, surgery may be required. It is important that the obstetrician examines the expelled placenta and fetal membranes to ensure that they are intact. If fragments of the placenta remain in the uterus, they can cause postpartum hemorrhage. Uterine contractions continue for several hours after birth to return the uterus to its pre-pregnancy size in a process called involution, which also allows the mother’s abdominal organs to return to their pre-pregnancy locations. Breastfeeding facilitates this process. Although postpartum uterine contractions limit blood loss from the detachment of the placenta, the mother does experience a postpartum vaginal discharge called lochia. This is made up of uterine lining cells, erythrocytes, leukocytes, and other debris. Thick, dark, lochia rubra (red lochia) typically continues for 2–3 days, and is replaced by lochia serosa, a thinner, pinkish form that continues until about the tenth postpartum day. After this period, a scant, creamy, or watery discharge called lochia alba (white lochia) may continue for another 1–2 weeks. | A: postpartum. |
What do you call the lightless part of the ocean?
Here are the choices:
A. photic zone
B. Davy Jones' Locker
C. aphotic zone
D. photoreactive zone | The small surface zone that has light is the photic zone. The entire rest of the ocean does not have light and is the aphotic zone. | C: aphotic zone. |
The creation of a voltage across a current-carrying conductor by a magnetic field is known as what?
Here are the choices:
A. show effect
B. off effect
C. hall effect
D. newton effect | 22.6 The Hall Effect We have seen effects of a magnetic field on free-moving charges. The magnetic field also affects charges moving in a conductor. One result is the Hall effect, which has important implications and applications. Figure 22.27 shows what happens to charges moving through a conductor in a magnetic field. The field is perpendicular to the electron drift velocity and to the width of the conductor. Note that conventional current is to the right in both parts of the figure. In part (a), electrons carry the current and move to the left. In part (b), positive charges carry the current and move to the right. Moving electrons feel a magnetic force toward one side of the conductor, leaving a net positive charge on the other side. This separation of charge creates a voltage ε , known as the Hall emf, across the conductor. The creation of a voltage across a current-carrying conductor by a magnetic field is known as the Hall effect, after Edwin Hall, the American physicist who discovered it in 1879. | C: hall effect. |
Pavement cells, large, irregularly shaped parenchymal cells which lack chloroplasts, make up the majority of what?
Here are the choices:
A. epidermis
B. Skin
C. layers
D. dermis | This tissue includes several types of specialized cells. Pavement cells, large, irregularly shaped parenchymal cells which lack chloroplasts, make up the majority of the epidermis. Within the epidermis, thousands of pairs of bean-shaped schlerenchymal guard cells swell and shrink by osmosis to open and close stomata , tiny pores which control the exchange of oxygen and carbon dioxide gases and the release of water vapor. The lower surfaces of some leaves contain as many as 100,000 stomata per square centimeter. | A: epidermis. |
What do convergent plate boundaries with trenches have?
Here are the choices:
A. volcanoes
B. earthquakes
C. caves
D. geysers | Volcanoes at divergent plate boundaries are in the East Pacific Rise. Convergent plate boundaries, where there are trenches, have volcanoes. Hotspot volcanoes are in chains in the middle of the ocean basin. | A: volcanoes. |
Around what percentage of the earth's surface water is contained in the ocean?
Here are the choices:
A. 92 %
B. 97%
C. 86 %
D. 99% | Oceans cover more than 70% of Earth's surface. Oceans hold 97% of the planet's surface water. It’s no surprise that the oceans have a big influence on the planet. The oceans affect the atmosphere, climate, and living things. | B: 97%. |
What celestial structure does not give off its own light?
Here are the choices:
A. meteors
B. asteroids
C. the moon
D. the stars | C: the moon. | |
Which rule is a result of trends in energies and is useful in explaining why atoms form the ions that they do?
Here are the choices:
A. coupling rule
B. electrons rule
C. nutron rule
D. octet rule | valence shell is called the octet rule. When atoms form compounds, the octet rule is not always satisfied for all atoms at all times, but it is a very good rule of thumb for understanding the kinds of bonding arrangements that atoms can make. It is not impossible to violate the octet rule. Consider sodium: in its elemental form, it has one valence electron and is stable. It is rather reactive, however, and does not require a lot of energy to remove that electron to make the Na+ ion. We could remove another electron by adding even more energy to the ion, to make the Na2+ ion. However, that requires much more energy than is normally available in chemical reactions, so sodium stops at a 1+ charge after losing a single electron. It turns out that the Na+ ion has a complete octet in its new valence shell, the n = 2 shell, which satisfies the octet rule. The octet rule is a result of trends in energies and is useful in explaining why atoms form the ions that they do. Now consider an Na atom in the presence of a Cl atom. The two atoms have these Lewis electron dot diagrams and electron configurations:. | D: octet rule. |
What is the second most common type of cancer in both men and women?
Here are the choices:
A. skin
B. lung
C. heart
D. breast | In both men and women, the second most common type of cancer is lung cancer. Most cases of lung cancer develop in people who smoke. | B: lung. |
What is the main difference between prokaryotic and eukaryotic cells?
Here are the choices:
A. absence of cytoplasm
B. presence of cytoplasm
C. presence of a nucleus
D. enlarged mitochondria | The answer depends on if the cell is prokaryotic or eukaryotic. The main difference between the two types of cells is the presence of a nucleus. In eukaryotic cells, DNA lives in the nucleus. | C: presence of a nucleus. |
What is a layer of saturated porous rock?
Here are the choices:
A. a shear
B. a quarry
C. an overhang
D. an aquifer | An aquifer is a layer of saturated porous rock. It lies below the water table. An impermeable layer, such as clay, is below the aquifer. | D: an aquifer. |
What element, which often forms polymers, has a unique ability to form covalent bonds with many other atoms?
Here are the choices:
A. hydrogen
B. carbon
C. oxygen
D. iron | Carbon has a unique ability to form covalent bonds with many other atoms. It can bond with other carbon atoms as well as with atoms of other elements. Because of this ability, carbon often forms polymers. A polymer is a large molecule that is made out of many smaller molecules that are joined together by covalent bonds. The smaller, repeating molecules are called monomers . (The prefix mono - means “one” and the prefix poly - means “many. ”) Polymers may consist of just one type of monomer or of more than one type. Polymers are similar to the strings of beads pictured in the Figure below . Like beads on a string, monomers in a polymer may be all the same or different from one another. | B: carbon. |
Early in the development of a human fetus, the skeleton is made entirely of what?
Here are the choices:
A. anterior
B. cartilage
C. membrane
D. bones | Early in the development of a human fetus, the skeleton is made entirely of cartilage. The relatively soft cartilage gradually changes to hard bone through ossification. This is a process in which mineral deposits replace cartilage in bone. At birth, several areas of cartilage remain, including the ends of the long bones in the arms and legs. This allows these bones to keep growing in length during childhood. | B: cartilage. |
What type of disease can be treated by radioactive elements in glucose?
Here are the choices:
A. genetic disorder
B. mutation
C. cancer
D. infection | Despite its dangers, radioactivity has several uses. It can be used to determine the ages of ancient rocks and fossils. This use of radioactivity is explained in this chapter’s "Radioactive Decay" lesson. Radioactivity can also be used as a source of power to generate electricity. This use of radioactivity is covered later on in this chapter in the lesson "Nuclear Energy. " Radioactivity can even be used to diagnose and treat diseases, including cancer. Cancer cells grow rapidly and take up a lot of glucose for energy. Glucose containing radioactive elements can be given to patients. Cancer cells will take up more of the glucose than normal cells do and give off radiation. The radiation can be detected with special machines (see Figure below ). Radioactive elements taken up by cancer cells may also be used to kill the cells and treat the disease. You can learn more about medical uses of radiation at the URL below. | C: cancer. |
What theory of gases describes this state of matter as composed of tiny particles in constant motion with a lot of distance between the particles?
Here are the choices:
A. kinetic
B. thermal
C. optical
D. magnetic | The kinetic theory of gases describes this state of matter as composed of tiny particles in constant motion with a lot of distance between the particles. This model of gases explains some of the physical properties of gases. Because most of a gas is empty space, a gas has a low density and can expand or contract under the appropriate influence. The fact that gas particles are in constant motion means that two or more gases will always mix, as the particles from the individual gases move and collide with each other. An ideal gas is a gas that exactly follows the statements of the kinetic theory. Unfortunately, real gases are not ideal. Many gases deviate slightly from agreeing perfectly with the kinetic theory of gases. However, most gases adhere to the statements so well that the kinetic theory of gases is well accepted by the scientific community. | A: kinetic. |
When egg laying and mating occur together, as in external fertilization, the certainty of what is high?
Here are the choices:
A. survival
B. high reproduction rate
C. germination
D. paternity | D: paternity. | |
What control reproductive cycles, which are in turn regulated by environmental cues?
Here are the choices:
A. brain waves
B. hormones
C. nerve impulses
D. enzymes | B: hormones. | |
Which gas is responsible for global warming?
Here are the choices:
A. carbon dioxide
B. ozone
C. hydrocarbons
D. oxygen | The atmosphere contains small amounts of carbon dioxide. Climatologists have found that humans are putting a lot of extra carbon dioxide into the atmosphere. This is mostly from burning fossil fuels. The extra carbon dioxide traps heat from the Sun. Trapped heat causes the atmosphere to heat up. We call this global warming ( Figure below ). | A: carbon dioxide. |
The short length of what in women is the best explanation for the greater incidence of uti in women?
Here are the choices:
A. urethra
B. uterus
C. fallopian tube
D. vagina | Female Urethra The external urethral orifice is embedded in the anterior vaginal wall inferior to the clitoris, superior to the vaginal opening (introitus), and medial to the labia minora. Its short length, about 4 cm, is less of a barrier to fecal bacteria than the longer male urethra and the best explanation for the greater incidence of UTI in women. Voluntary control of the external urethral sphincter is a function of the pudendal nerve. It arises in the sacral region of the spinal cord, traveling via the S2–S4 nerves of the sacral plexus. | A: urethra. |
What type of cells are flagella rare in?
Here are the choices:
A. intracellular
B. eukaryotic
C. cancer.
D. synthetic | Some bacteria also have tail-like structures called flagella ( Figure below ). Flagella help bacteria move. As the flagella rotate, they spin the bacteria and propel them forward. It is often said the flagella looks like a tiny whip, propelling the bacteria forward. Though some eukaryotic cells do have a flagella, a flagella in eukaryotes is rare. | B: eukaryotic. |
Solids and liquids are phases of matter that have their own unique what?
Here are the choices:
A. temperatures
B. masses
C. properties
D. volumes | Solids and liquids are phases that have their own unique properties. | C: properties. |
What do many fungi secrete that break down complex molecules to smaller molecules that can be absorbed?
Here are the choices:
A. enzymes
B. hormones
C. carbohydrates
D. water vapor | A: enzymes. | |
All three types of convergent plate boundaries produce what destructive phenomenon?
Here are the choices:
A. storm
B. tornado
C. volcano
D. earthquake | All three types of convergent plate boundaries produce massive earthquakes. | D: earthquake. |
How do plants obtain their energy?
Here are the choices:
A. Sugar Transfer
B. photosynthesis
C. glycolysis
D. HETEROTROPHS | Seaweed is actually a plant-like protist, which are also known as algae. The green color is due to what pigment? Algae, like plants, obtain their energy through photosynthesis. | B: photosynthesis. |
The mouth, stomach, esophagus, small intestine, and large intestine are all part of what organ system?
Here are the choices:
A. digestive
B. muscular
C. lymphatic
D. respiratory | The mouth and stomach are just two of the organs of the digestive system. Other digestive system organs are the esophagus, small intestine, and large intestine. Below, you can see that the digestive organs form a long tube ( Figure below ). In adults, this tube is about 30 feet long! At one end of the tube is the mouth. At the other end is the anus. Food enters the mouth and then passes through the rest of the digestive system. Food waste leaves the body through the anus. | A: digestive. |
An environment in which cells neither sink nor swell is known as what?
Here are the choices:
A. isotonic environment
B. exothermic environment
C. pressured environment
D. electrolyte environment | Figure 41.2 Cells placed in a hypertonic environment tend to shrink due to loss of water. In a hypotonic environment, cells tend to swell due to intake of water. The blood maintains an isotonic environment so that cells neither shrink nor swell. (credit: Mariana Ruiz Villareal). | A: isotonic environment. |
Particulates from cigarette smoke that enter what structures can cause a permanent reduction in lung capacity?
Here are the choices:
A. chambers
B. glands
C. cells
D. alveoli | D: alveoli. | |
Terrestrial arthropods generally have internal surfaces specialized for what?
Here are the choices:
A. gas exchange
B. food gathering
C. water uptake
D. protection | A: gas exchange. | |
What are the two groups that tripoblastic eucoelomates can be divided into based on early embryonic development differences?
Here are the choices:
A. protostomes and deuterostomes
B. protostomes and eurostomes
C. heterodimers and deuterostomes
D. odontoblasts and deuterostomes | Protostomes and Deuterostomes Bilaterally symmetrical, triploblastic eucoelomates can be divided into two groups based on differences in their early embryonic development. Protostomes include phyla such as arthropods, mollusks, and annelids. Deuterostomes include. | A: protostomes and deuterostomes. |
What part of the cell is surrounded by a membrane and holds the genetic information for the cell?
Here are the choices:
A. upper
B. nucleus
C. lower
D. cell wall | All living cells are surrounded by a cell membrane. Plant cells (Figure 17.3 "An Idealized Plant Cell") and animal cells (Figure 17.4 "An Idealized Animal Cell") contain a cell nucleus that is also surrounded by a membrane and holds the genetic information for the cell. (For more information about genetics and DNA, see Chapter 19 "Nucleic Acids". ) Everything between the cell membrane and the nuclear membrane—including Saylor URL: http://www. saylor. org/books. | B: nucleus. |
What are angiosperms most important function to humans?
Here are the choices:
A. gasoline
B. food
C. oxygen production
D. water filtration | Angiosperms are important to humans in many ways, but the most significant role of angiosperms is as food. Wheat, rye, corn, and other grains are all harvested from flowering plants. Starchy foods, such as potatoes, and legumes, such as beans, are also angiosperms. And, as mentioned previously, fruits are a product of angiosperms that increase seed dispersal and are nutritious. | B: food. |
How many atoms are evenly organized around a central atom?
Here are the choices:
A. seven
B. four
C. six
D. five | Six atoms are evenly organized around a central atom. | C: six. |
What are formed by atoms gaining electrons?
Here are the choices:
A. oxides
B. ions
C. cations
D. anions | Figure 7.10 Cations are formed when atoms lose electrons, represented by fewer Lewis dots, whereas anions are formed by atoms gaining electrons. The total number of electrons does not change. | D: anions. |
What type of fish are the majority of living species?
Here are the choices:
A. ray-finned fish
B. lungfish
C. cartilaginous fish
D. freshwater fish | Ray-finned fish include the majority of living fish species, including goldfish, tuna, salmon, perch, and cod. They have a bony endoskeleton and a swim bladder. Their thin fins consist of webs of skin over flexible bony rays, or spines. The fins lack muscle, so their movements are controlled by muscles in the body wall. You can compare their ray fins with the fleshy fins of lobe-finned fish in Figure below . | A: ray-finned fish. |
What are the light highlands of the moon called?
Here are the choices:
A. kepler hills
B. terrae
C. craters
D. mariae | The lunar surface has dark basalt maria. The light highlands are called terrae. | B: terrae. |
The shape of earlobes is an example of what kind of trait, which is influenced by genes and passed along through generations?
Here are the choices:
A. inherited trait
B. instinct
C. genetic disorder
D. acquired trait | Human earlobes may be attached or free. You inherited the particular shape of your earlobes from your parents. Inherited traits are influenced by genes, which are passed on to offspring and future generations. Things not influenced by genes are not passed on to your offspring. Natural selection only operates on traits like earlobe shape that have a genetic basis, not on traits that are acquired, like a summer tan. | A: inherited trait. |
Mosses, liverworts, and hornworts are examples of what type of plant in which gametophyte generation is dominant?
Here are the choices:
A. photoreactive plants
B. choanocyte plants
C. vascular plants
D. nonvascular plants | Nonvascular plants include mosses, liverworts, and hornworts. They are the only plants with a life cycle in which the gametophyte generation is dominant. Figure below shows the life cycle of moss. The familiar, green, photosynthetic moss plants are gametophytes. The sporophyte generation is very small and dependent on the gametophyte plant. | D: nonvascular plants. |
Release of spores in a suitable environment will lead to germination and a new generation of what?
Here are the choices:
A. gametophytes
B. filaments
C. seeds
D. assemblages | plants—the pterophytes—from which modern ferns are derived. The lifecycle of bryophytes and pterophytes is characterized by the alternation of generations, like gymnosperms and angiosperms; what sets bryophytes and pterophytes apart from gymnosperms and angiosperms is their reproductive requirement for water. The completion of the bryophyte and pterophyte life cycle requires water because the male gametophyte releases sperm, which must swim—propelled by their flagella—to reach and fertilize the female gamete or egg. After fertilization, the zygote matures and grows into a sporophyte, which in turn will form sporangia or "spore vessels. " In the sporangia, mother cells undergo meiosis and produce the haploid spores. Release of spores in a suitable environment will lead to germination and a new generation of gametophytes. In seed plants, the evolutionary trend led to a dominant sporophyte generation, and at the same time, a systematic reduction in the size of the gametophyte: from a conspicuous structure to a microscopic cluster of cells enclosed in the tissues of the sporophyte. Whereas lower vascular plants, such as club mosses and ferns, are mostly homosporous (produce only one type of spore), all seed plants, or spermatophytes, are heterosporous. They form two types of spores: megaspores (female) and microspores (male). Megaspores develop into female gametophytes that produce eggs, and microspores mature into male gametophytes that generate sperm. Because the gametophytes mature within the spores, they are not free-living, as are the gametophytes of other seedless vascular plants. Heterosporous seedless plants are seen as the evolutionary forerunners of seed plants. Seeds and pollen—two critical adaptations to drought, and to reproduction that doesn’t require water—distinguish seed plants from other (seedless) vascular plants. Both adaptations were required for the colonization of land begun by the bryophytes and their ancestors. Fossils place the earliest distinct seed plants at about 350 million years ago. The first reliable record of gymnosperms dates their appearance to the Pennsylvanian period, about 319 million years ago (Figure 26.2). Gymnosperms were preceded by progymnosperms, the first naked seed plants, which arose about 380 million years ago. Progymnosperms were a transitional group of plants that superficially resembled conifers (cone bearers) because they produced wood from the secondary growth of the vascular tissues; however, they still reproduced like ferns, releasing spores into the environment. Gymnosperms dominated the landscape in the early (Triassic) and middle (Jurassic) Mesozoic era. Angiosperms surpassed gymnosperms by the middle of the Cretaceous (about 100 million years ago) in the late Mesozoic era, and today are the most abundant plant group in most terrestrial biomes. | A: gametophytes. |
Why are living things considered to be renewable?
Here are the choices:
A. they inherit traits
B. they reproduce
C. they decompose
D. they evolve | Living things are considered to be renewable. This is because they can reproduce to replace themselves. However, they can be over-used or misused to the point of extinction. To be truly renewable, they must be used sustainably. Sustainable use is the use of resources in a way that meets the needs of the present and also preserves the resources for future generations. | B: they reproduce. |
What is the term for the metabolic reaction where living systems build new molecules?
Here are the choices:
A. metabolism
B. anabolism
C. symbolism
D. connectionism | Plants and animals exist in a cycle; each requires products of the other. The thousands of coordinated chemical reactions that keep cells alive are referred to collectively as metabolism. In general, metabolic reactions are divided into two classes: the breaking down of molecules to obtain energy is catabolism, and the building of new molecules needed by living systems is anabolism. | B: anabolism. |
Name the three types of muscle tissue.
Here are the choices:
A. cardiac, smooth, long
B. skeletal, smooth, cardiac
C. smooth, long, tight
D. skeletal, cardiac, long | Figure 16.17 The body contains three types of muscle tissue: skeletal muscle, smooth muscle, and cardiac muscle. Notice that skeletal muscle cells are long and cylindrical, they have multiple nuclei, and the small, dark nuclei are pushed to the periphery of the cell. Smooth muscle cells are short, tapered at each end, and have only one nucleus each. Cardiac muscle cells are also cylindrical, but short. The cytoplasm may branch, and they have one or two nuclei in the center of the cell. (credit: modification of work by NCI, NIH; scale-bar data from Matt Russell). | B: skeletal, smooth, cardiac. |
Cellular respiration and photosynthesis are important parts of which cycle?
Here are the choices:
A. carbon cycle
B. vapor cycle
C. greenhouse effect
D. water cycle | Cellular respiration and photosynthesis are important parts of the carbon cycle. The carbon cycle is the pathways through which carbon is recycled in the biosphere. While cellular respiration releases carbon dioxide into the environment, photosynthesis pulls carbon dioxide out of the atmosphere. The exchange of carbon dioxide and oxygen during photosynthesis ( Figure below ) and cellular respiration worldwide helps to keep atmospheric oxygen and carbon dioxide at stable levels. | A: carbon cycle. |
What are the winds that occur in belts that encircle the planet?
Here are the choices:
A. new winds
B. global winds
C. galactic winds
D. global rains | Before catalytic converters were required, cars spewed a lot of pollutants into the air. On the left is a car without a catalytic converter. The car on the right has one. | B: global winds. |
Human mammary glands can produce what substance, which can be used to feed children?
Here are the choices:
A. edema
B. sperm
C. urea
D. milk | The mother’s mammary glands go through changes during the third trimester to prepare for lactation and breastfeeding. When the baby begins suckling at the breast, signals are sent to the hypothalamus causing the release of prolactin from the anterior pituitary. Prolactin causes the mammary glands to produce milk. Oxytocin is also released, promoting the release of the milk. The milk contains nutrients for the baby’s development and growth as well as immunoglobulins to protect the child from bacterial and viral infections. | D: milk. |
What is a prerequisite for fertilization to take place in plants?
Here are the choices:
A. photosynthesis
B. germination
C. pollination
D. mitosis | Pollination must occur for fertilization to take place. Zygotes develop into embryos inside seeds, from which the next sporophyte generation grows. | C: pollination. |
Water is allowed to flow downhill into a large turbine to harness power. what helps the turbine spin?
Here are the choices:
A. polar energy
B. electrostatic energy
C. kinetic energy
D. residual energy | To harness water power, a stream must be dammed. Narrow valleys are the best for dams. While sitting in the reservoir behind the dam, the water has potential energy. Water is allowed to flow downhill into a large turbine. While flowing downhill, the water has kinetic energy. Kinetic energy makes the turbine spin. The turbine is connected to a generator, which makes electricity. | C: kinetic energy. |
The movement of bone away from the midline of the body is called what?
Here are the choices:
A. flexion
B. continuation
C. extension
D. spring | The movement of bone away from the midline of the body is called ________. circumduction b. extension c. adduction d. abduction. | C: extension. |
What occurs when so much water enters a stream or river that it overflows its banks or when deep snow melts very quickly in spring?
Here are the choices:
A. storm
B. flooding
C. avalanche
D. drought | A flood occurs when so much water enters a stream or river that it overflows its banks. Flood waters from a river are shown in Figure below . Like this flood, many floods are caused by very heavy rains. Floods may also occur when deep snow melts quickly in the spring. | B: flooding. |
What is the cause of the “heartburn” that occurs when acidic digestive juices escape into the esophagus?
Here are the choices:
A. acidic buildup
B. acid reflux
C. acid pressure
D. toxic reflux | sphincter, but the esophagus remains closed when there is no swallowing action. Acid reflux or “heartburn” occurs when the acidic digestive juices escape into the esophagus. Stomach A large part of digestion occurs in the stomach, shown in Figure 34.11. The stomach is a saclike organ that secretes gastric digestive juices. The pH in the stomach is between 1.5 and 2.5. This highly acidic environment is required for the chemical breakdown of food and the extraction of nutrients. When empty, the stomach is a rather small organ; however, it can expand to up to 20 times its resting size when filled with food. This characteristic is particularly useful for animals that need to eat when food is available. | B: acid reflux. |
By 180 million years ago, pangaea began to do what?
Here are the choices:
A. break up
B. combine
C. freeze
D. grow | By 180 million years ago, Pangaea began to break up. The continents started to drift apart. They slowly moved to where they are today. The movement of the continents caused Panthalassa to break into smaller oceans. These oceans are now known as the Pacific, Atlantic, Indian, and Arctic Oceans. The waters of all the oceans are connected. That’s why some people refer to the oceans together as the “World Ocean. ”. | A: break up. |
What has a single voltage source and a single resistor
Here are the choices:
A. simple circuit
B. stuff circuit
C. pattern circuit
D. complex circuit | Figure 20.8 shows the schematic for a simple circuit. A simple circuit has a single voltage source and a single resistor. The wires connecting the voltage source to the resistor can be assumed to have negligible resistance, or their resistance can be included in R . | A: simple circuit. |
What property is associated with the number of reactant molecules involved in an elementary step?
Here are the choices:
A. pollenation
B. Molecules
C. molecularity
D. kilocalorie | The number of reactant molecules in an elementary step is referred to as its molecularity. The vast majority of elementary steps are unimolecular or bimolecular. | C: molecularity. |
During an earthquake, wet soils become like what?
Here are the choices:
A. sand
B. rock
C. water
D. quicksand | The amount of damage also depends on the geology of the region. Strong, solid bedrock shakes less than soft or wet soils. Wet soils liquefy during an earthquake and become like quicksand. Soil on a hillside that is shaken loose can become a landslide. | D: quicksand. |
What helps sound travel in waves?
Here are the choices:
A. gases
B. molecules
C. speaker placements
D. temperatures | Sound is a form of energy that travels in waves. Sound waves cannot travel through empty space, but they can travel through gases. Gases in the air allow us to hear most of the sounds in our world. Because of air, you can hear birds singing, horns tooting, and friends laughing. Without the atmosphere, the world would be a silent, eerie place. | A: gases. |
What kind of relationship between glucagon and insulin is vital to managing fuel storage and consumption by body cells?
Here are the choices:
A. sympathetic
B. opportunistic
C. commensalism
D. antagonistic | D: antagonistic. | |
The yellowstone hot spot is a famous example of a what?
Here are the choices:
A. form hot spot
B. oceanic hot spot
C. deeper hot spot
D. continental hot spot | Hot spots are found within continents, but not as commonly as within oceans. The Yellowstone hot spot is a famous example of a continental hot spot. | D: continental hot spot. |
Ionic compounds take on the form of extended three-dimensional arrays of cations and what else?
Here are the choices:
A. anions
B. electrons
C. crystals
D. oxides | Ionic compounds take on the form of extended three-dimensional arrays of cations and anions. | A: anions. |
Electric generators convert what type of energy to electric energy?
Here are the choices:
A. mechanical energy
B. thermodynamic energy
C. electromagnetic energy
D. fluid energy | Electric generators convert mechanical energy to electric energy. The generator consists of some number of wire loops wrapped around an iron core and placed in a strong magnetic field. The loops of wire and the iron core are called the armature . The armature is mounted so that it can rotate freely inside the magnetic field. Mechanical energy is used to spin the armature in the field so that the wire loops cut across the field and produce electric current. The of this current is calculated by . | A: mechanical energy. |
What can autographs do that heterotrophs cannot do?
Here are the choices:
A. live without water
B. make their own air
C. make their own food
D. live without sleep | Heterotrophs cannot make their own food, so they must eat or absorb it. For this reason, heterotrophs are also known as consumers . Consumers include all animals and fungi and many protists and bacteria. They may consume autotrophs or other heterotrophs or organic molecules from other organisms. Heterotrophs show great diversity and may appear far more fascinating than producers. But heterotrophs are limited by our utter dependence on those autotrophs that originally made our food. If plants, algae, and autotrophic bacteria vanished from earth, animals, fungi, and other heterotrophs would soon disappear as well. All life requires a constant input of energy. Only autotrophs can transform that ultimate, solar source into the chemical energy in food that powers life, as shown in Figure below . | C: make their own food. |
The primary amine in which the nitrogen atom is attached directly to a benzene ring has a special name, what is it?
Here are the choices:
A. aniline
B. nitrate
C. cyanide
D. aldehyde | The primary amine in which the nitrogen atom is attached directly to a benzene ring has a special name—aniline. Aryl amines are named as derivatives of aniline. | A: aniline. |
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