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sciq
sciq_3540
The human body has as many as two trillion lymphocytes, and lymphocytes make up about 25% of all of what?
[ "pathogens", "glands", "red blood cells", "leukocytes" ]
The human body has as many as two trillion lymphocytes, and lymphocytes make up about 25% of all leukocytes. The majority of lymphocytes are found in the lymphatic system, where they are most likely to encounter pathogens. The rest are found in the blood. There are two major types of lymphocytes, called B cells and T c...
D
null
sciq
sciq_6120
Sutures, gomphoses, and syndesmoses are types of what, which are found where adjacent bones are strongly united by connective tissue?
[ "fibrous joints", "metallic joints", "ligaments", "cartilage" ]
9.2 Fibrous Joints Fibrous joints are where adjacent bones are strongly united by fibrous connective tissue. The gap filled by connective tissue may be narrow or wide. The three types of fibrous joints are sutures, gomphoses, and syndesmoses. A suture is the narrow fibrous joint that unites most bones of the skull. At ...
A
null
sciq
sciq_8622
What is the force of attraction between two masses?
[ "electricity", "gravity", "inertia", "momentum" ]
Gravity is traditionally defined as a force of attraction between two masses. Weight measures the force of gravity and is expressed in newtons (N).
B
null
sciq
sciq_10790
When bacteria enter the bloodstream, the result is what condition?
[ "hypertension", "hypoxia", "septicemia", "diarrhea" ]
Most UTIs are not serious, but some infections can lead to serious problems. Long lasting kidney infections can cause permanent damage, including kidney scars, poor kidney function, high blood pressure, and other problems. Some sudden kidney infections can be life threatening, especially if the bacteria enter the blood...
C
null
sciq
sciq_4381
What devices convert mechanical energy to electric energy?
[ "mechanical generators", "transformation generators", "kinetic generators", "electric generators" ]
Electric generators convert mechanical energy to electric energy.
D
null
sciq
sciq_3471
The primary lymphoid organs are the bone marrow and what else?
[ "kidneys", "pinneal gland", "thyroid", "thymus gland" ]
Primary Lymphoid Organs and Lymphocyte Development Understanding the differentiation and development of B and T cells is critical to the understanding of the adaptive immune response. It is through this process that the body (ideally) learns to destroy only pathogens and leaves the body’s own cells relatively intact. T...
D
null
sciq
sciq_4128
Distance traveled divided by time is equal to what?
[ "speed", "frequency", "momentum", "direction" ]
Average speed is calculated by dividing the total distance travelled by the time interval. For example, someone who takes 40 minutes to drive 20 miles north and then 20 miles south (to end up at the same place), has an average speed of 40 miles divided by 40 minutes, or 1 mile per minute (60 mph). Average velocity, how...
A
null
sciq
sciq_2761
What forms when a solute dissolves in a solvent?
[ "chemical", "liquid", "gas", "solution" ]
A solution forms when a solute dissolves in a solvent. The rate of dissolving is faster with stirring, a higher temperature, or greater surface area. Many solutes are soluble in water because water is polar.
D
null
sciq
sciq_2852
The temperature at which all molecular motion has ceased is called what?
[ "0 degrees celcius", "0 degrees kelvin", "stopping point", "absolute zero" ]
Making Connections: Absolute Zero What is absolute zero? Absolute zero is the temperature at which all molecular motion has ceased. The concept of absolute zero arises from the behavior of gases. Figure 13.9 shows how the pressure of gases at a constant volume decreases as temperature decreases. Various scientists have...
D
null
sciq
sciq_7435
What form does water take on the planet mars?
[ "liquid", "ice", "gas", "plasma" ]
Water on Mars can't be a liquid. This is because the pressure of the atmosphere is too low. The planet does have a lot of water; it is in the form of ice. The south pole of Mars has a very visible ice cap. Scientists also have evidence that there is also a lot of ice just under the Martian surface. The ice melts when v...
B
null
sciq
sciq_1218
Occuring throughout the lifespan of the organism, what stages proceed in a certain order?
[ "life cycle stages", "genetic stages", "yearly stages", "life effectiveness stages" ]
A
null
sciq
sciq_2896
What did roots evolve from that plants used for aborption?
[ "leguminous", "rhizoids", "oomycetes", "seeds" ]
Roots are vascular organs that can penetrate soil and even rock. They absorb water and minerals from soil and carry them to leaves. They also anchor a plant in the soil. Roots evolved from rhizoids, which nonvascular plants had used for absorption.
B
null
sciq
sciq_2121
What is the diffusion of water known as?
[ "electrolysis", "hemostasis", "evaporation", "osmosis" ]
Osmosis is the special case of the diffusion of water. It's an important means of transport in cells because the fluid inside and outside cells is mostly water. Water can pass through the cell membrane by simple diffusion, but it can happen more quickly with the help of channel proteins. Water moves in or out of a cell...
D
null
sciq
sciq_2540
What might a scientist do to confirm the work of another?
[ "study their work", "develop a completely different experiment", "question their methods", "replicate their work" ]
Scientists may work together on a project. One reason is that they can share equipment and personnel. Another reason is that they can share ideas. Scientists may also work separately. Even then, they use each other's data and interpretations. When one scientist publishes a paper, others will replicate the work to make ...
D
null
sciq
sciq_2816
Most metals exist in which form at room temperature?
[ "solids", "liquids", "gases", "oils" ]
Matter typically exists in one of three states: solid, liquid, or gas. The state of a given substance is a physical property. Some substances exist as gases at room temperature (such as oxygen and carbon dioxide), while others (like water and mercury metal) exist as liquids. Most metals exist as solids at room temperat...
A
null
sciq
sciq_3404
All chemical changes involve a transfer of what?
[ "fuel", "energy", "pressure", "oxygen" ]
Describe ways protists are important to humans.
B
null
sciq
sciq_2730
What three primary colors of light can be distinguished by the human eye?
[ "red, green, yellow", "yellow, green, blue", "blue, red, orange", "red, green, blue" ]
The human eye can distinguish only red, green, and blue light. These three colors are the primary colors of light. All other colors of light can be created by combining the primary colors. Secondary colors of light—cyan, yellow, and magenta—form when two primary colors combine equally.
D
null
sciq
sciq_2469
Earth rotates on its axis once each day and revolves around the sun how often?
[ "ever 3 years", "every other year", "once each month", "once each year" ]
Earth rotates on its axis once each day and revolves around the Sun once every year.
D
null
sciq
sciq_8521
What do you call the diffusion of solutes through transport proteins in the plasma membrane?
[ "necessitated diffusion", "facilitated diffusion", "Osmosis", "exposed diffusion" ]
What happens if a substance needs assistance to move across or through the plasma membrane? Facilitated diffusion is the diffusion of solutes through transport proteins in the plasma membrane. Facilitated diffusion is a type of passive transport. Even though facilitated diffusion involves transport proteins, it is stil...
B
null
sciq
sciq_4057
Burning trees produces most of the same pollutants as burning what?
[ "coal fuels", "fossil compounds", "carbon", "fossil fuels" ]
Millions of acres of forest have been cut and burned to make way for farming. Figure below shows an example. Burning trees produces most of the same pollutants as burning fossil fuels.
D
null
sciq
sciq_320
In the chest, the trachea divides as it enters the lungs to form the right and left what?
[ "atrium", "bronchi", "ventricle", "alveoli" ]
In the chest, the trachea divides as it enters the lungs to form the right and left bronchi . The bronchi contain cartilage, which prevents them from collapsing. Mucus in the bronchi traps any remaining particles in air. Tiny, hair-like structures called cilia line the bronchi and sweep the particles and mucus toward t...
B
null
sciq
sciq_10478
Under which conditions do many bacteria carry out alcohol fermentation?
[ "melting", "photosynthesis", "enzymatic", "anaerobic" ]
D
null
sciq
sciq_563
In multicellular organisms, mutations can be subdivided into germline mutations and?
[ "resultant mutations", "somatic mutations", "elective mutations", "comparative mutations" ]
Once again, a mutation is the change in the DNA or RNA sequence. In multicellular organisms, mutations can be subdivided into germline mutations and somatic mutations. Germline mutations occur in the DNA of sex cells, or gametes, and are therefore potentially very serious. These mutations can be passed to the next gene...
B
null
sciq
sciq_3988
What is composed of a calcium cation and a nitrate anion?
[ "calcium carbonate", "calcium nitrate", "dynamite", "nitrous oxide" ]
Writing a formula for a ternary ionic compound also involves the same steps as for a binary ionic compound. Write the symbol and charge of the cation followed by the symbol and charge of the anion. Use the crisscross method to ensure that the final formula is neutral. Calcium nitrate is composed of a calcium cation and...
B
null
sciq
sciq_5402
Compounds that contain mainly the elements carbon and hydrogen are called what kind of compounds?
[ "natural compounds", "reactive compounds", "microscopic compounds", "organic compounds" ]
Compounds that contain mainly the elements carbon and hydrogen are called organic compounds . This is because they are found mainly in living organisms. Most organic compounds are held together by covalent bonds. An example of an organic compound is glucose (C 6 H 12 O 6 ), which is shown in Figure below . Glucose is a...
D
null
sciq
sciq_9468
Cardiac veins parallel the small cardiac arteries and generally drain into what sinus?
[ "lungs", "coronary", "heart", "Veins" ]
CHAPTER REVIEW 19.1 Heart Anatomy The heart resides within the pericardial sac and is located in the mediastinal space within the thoracic cavity. The pericardial sac consists of two fused layers: an outer fibrous capsule and an inner parietal pericardium lined with a serous membrane. Between the pericardial sac and th...
B
null
sciq
sciq_10000
Why does water infiltrate the ground?
[ "run-off from flooding", "prolonged drought conditions", "gravity", "because soil and rocks are porous" ]
Water infiltrates the ground because soil and rock are porous. Between the grains are pores, or tiny holes. Since water can move through this rock it is permeable. Eventually, the water reaches a layer of rock that is not porous and so is impermeable. Water stops moving downward when it reaches this layer of rock.
D
null
sciq
sciq_2186
Any sound with a frequency above the highest audible frequency is defined as what, a phenomenon useful in medical diagnosis and therapy?
[ "laser", "extrasound", "ultrasound", "radiation" ]
Any sound with a frequency above 20,000 Hz (or 20 kHz)—that is, above the highest audible frequency—is defined to be ultrasound. In practice, it is possible to create ultrasound frequencies up to more than a gigahertz. (Higher frequencies are difficult to create; furthermore, they propagate poorly because they are very...
C
null
sciq
sciq_11611
What is the upper-most atmosphere known as?
[ "exosphere", "thermosphere", "xerosphere", "ionosphere" ]
The atmosphere is a big part of the water cycle. What do you think would happen to Earth’s water without it?.
B
null
sciq
sciq_2869
Made of hot, solid rock, the mantle is beneath what layer of the earth?
[ "crust", "liquid", "core", "volcanic" ]
Beneath the crust is the mantle . The mantle is made of hot, solid rock. They know this because of seismic waves, meteorites, and the heat that comes from inside the planet. Mantle rock is mostly peridotite , which is rich in iron and magnesium ( Figure below ). Peridotite is rare at Earth's surface.
A
null
sciq
sciq_8980
Precipitation, evaporation, transpiration, and condensation are part of what cycle?
[ "water cycle", "cold cycle", "life cycle", "air cycle" ]
The water cycle includes the ocean, atmosphere, ground, and living things. During the water cycle, water keeps changing state by processes such as evaporation, transpiration, condensation, and precipitation.
A
null
sciq
sciq_8984
What do you call the fixed point of a lever?
[ "base", "fulcrum", "apex", "caliper" ]
A lever is a simple machine consisting of a bar that rotates around a fixed point. The fixed point of a lever is called the fulcrum. Like other machines, a lever makes work easier by changing the force applied to the machine or the distance over which the force is applied. For a video introduction to levers using skate...
B
null
sciq
sciq_6808
Electrical messages are carried by chemicals called what?
[ "Biotoxins", "neurotransmitters", "amino acids", "receptors" ]
tiny gap between two adjacent neurons across which electrical messages are carried by chemicals called neurotransmitters.
B
null
sciq
sciq_2820
What is a soft, gray, nontoxic alkaline earth metal?
[ "magnesium", "potassium", "pewter", "calcium" ]
For a better understanding of alkaline Earth metals, let’s take a closer look at two of them: calcium (Ca) and strontium (Sr). Calcium is a soft, gray, nontoxic alkaline Earth metal. Although pure calcium doesn’t exist in nature, calcium compounds are very common in Earth’s crust and in sea water. Calcium is also the m...
D
null
sciq
sciq_3654
What are the three major types of blood vessels?
[ "arteries, capilaries, tubes", "sculptures , veins , capillaries", "arteries, veins, capillaries", "arteries , pups , capillaries" ]
Blood vessels form a network throughout the body to transport blood to all the body cells. There are three major types of blood vessels: arteries, veins, and capillaries. All three are shown in Figure below and described below.
C
null
sciq
sciq_6778
What always has the same elements in the same ratio?
[ "cell", "mitochondria", "compound", "component" ]
A compound always consists of the same elements in the same ratio. If the same elements combine in different ratios, they form different compounds.
C
null
sciq
sciq_37
Interstitial carbides are produced by the reaction of most transition metals at high temperatures with what element?
[ "carbon", "oxygen", "hydrogen", "nitrogen" ]
temperatures with electropositive metals such as those of groups 1 and 2 and aluminum produces ionic carbides, which contain discrete metal cations and carbon anions. The identity of the anions depends on the size of the second element. For example, smaller elements such as beryllium and aluminum give methides such as ...
A
null
sciq
sciq_8071
What type of current do generators in cars use?
[ "direct current", "alternating current", "magnum current", "polar current" ]
Generators may be set up to produce either alternating or direct current. Generators in cars and most power plants produce alternating current.
B
null
sciq
sciq_3646
What are the organized instructions within dna for making proteins called?
[ "genes", "replicants", "clones", "genomes" ]
The DNA of a chromosome is encoded with genetic instructions for making proteins. These instructions are organized into units called genes . Most genes contain the instructions for a single protein. There may be hundreds or even thousands of genes on a single chromosome.
A
null
sciq
sciq_3170
During the scientific revolution, who proposed that the sun, not earth, is the center of the solar system?
[ "Galileo", "copernicus", "janus", "Newton" ]
The Scientific Revolution occurred in Europe. This was the beginning of modern Western science. Many scientific advances were made during this time. Copernicus proposed that the sun, not Earth, is the center of the solar system.
B
null
sciq
sciq_5848
The temperature of an object is a measure of what type of energy?
[ "density", "magnetic", "thermal", "chemical" ]
Forms of Energy The forms of energy include thermal energy, radiant energy, electrical energy, nuclear energy, and chemical energy (Figure 5.1 "Forms of Energy"). Thermal energy results from atomic and molecular motion; the faster the motion, the greater the thermal energy. The temperature of an object is a measure of ...
C
null
sciq
sciq_6049
What two types of juices help digestion within the small intestine?
[ "bile and lymph", "amniotic fluid, bile", "chyme and phloem", "intestinal and pancreatic" ]
Chemical Digestion in the Small Intestine The digestion of proteins and carbohydrates, which partially occurs in the stomach, is completed in the small intestine with the aid of intestinal and pancreatic juices. Lipids arrive in the intestine largely undigested, so much of the focus here is on lipid digestion, which is...
D
null
sciq
sciq_3600
An electromagnetic wave begins with what movement by an electrically charged particle?
[ "vibration", "acceleration", "diffusion", "momentum" ]
An electromagnetic wave begins when an electrically charged particle vibrates. This causes a vibrating electric field, which in turn creates a vibrating magnetic field. The two vibrating fields together form an electromagnetic wave.
A
null
sciq
sciq_5256
Are vesicles larger or smaller than vacuoles?
[ "larger", "smaller", "wider", "narrower" ]
Vesicles are much smaller than vacuoles and have a variety of functions. Some vesicles pinch off from the membranes of the endoplasmic reticulum and Golgi apparatus. These vesicles store and transport proteins and lipids. Other vesicles are used as chambers for biochemical reactions.
B
null
sciq
sciq_6402
What term is used to describe the full range of electromagnetic waves?
[ "electromagnetic spectrum", "electromagnetic series", "electromagnetic scale", "mechanical spectrum" ]
Electromagnetic waves vary in their wavelength, frequency, and energy. The full range of electromagnetic waves makes up the electromagnetic spectrum.
A
null
sciq
sciq_4653
In most crustaceans, what two structures fuse to form a cephalothorax?
[ "wing and legs", "foot and toes", "head and thorax", "body and shoulders" ]
Unlike that of the Hexapoda, the head and thorax of most crustaceans is fused to form a cephalothorax (Figure 28.40), which is covered by a plate called the carapace, thus producing a body structure of two tagma. Crustaceans have a chitinous exoskeleton that is shed by molting whenever the animal increases in size. The...
C
null
sciq
sciq_2961
What category of animals in the vertebrate group has a relatively small brain but highly developed sense organs?
[ "fish", "arthropods", "primates", "mammals" ]
Fish have a nervous system with a brain. Fish brains are small compared with the brains of other vertebrates. However, they are large and complex compared with the brains of invertebrates. Fish also have highly developed sense organs. They include organs to see, hear, feel, smell, and taste.
A
null
sciq
sciq_90
Sexual reproduction involves haploid gametes and produces a diploid zygote through what process?
[ "sedimentation", "fertilization", "vivisection", "infection" ]
Sexual reproduction involves haploid gametes and produces a diploid zygote through fertilization.
B
null
sciq
sciq_1574
The central vacuole maintains turgor pressure against what?
[ "the cell wall", "the cell addition", "the cell move", "the cell multiplication" ]
The central vacuole maintains turgor pressure against the cell wall.
A
null
sciq
sciq_9183
An alloy is a mixture of what with one or more other substances?
[ "protein", "metal", "acid", "water" ]
Like salt water in the ocean, many solutions are normally in the liquid state. However, matter in any state can form a solution. An alloy, which is a mixture of a metal with one or more other substances, is a solid solution at room temperature. For example, the alloy bronze is a solution of copper and tin. Matter in th...
B
null
sciq
sciq_1586
Which chemical element is the basis of all life on earth?
[ "carbon", "oxygen", "nitrogen", "hydrogen" ]
Carbon is an element. Carbon is the basis of all life on Earth. Since carbon can combine with many other elements it forms a variety of different substances.
A
null
sciq
sciq_2479
In physics, resistance is opposition to the flow of what?
[ "electrical charges", "capacitance", "temperature charges", "surface flow" ]
In physics, resistance is opposition to the flow of electric charges in an electric current as it travels through matter. The SI unit for resistance is the ohm. Resistance occurs because moving electrons in current bump into atoms of matter. Resistance reduces the amount of electrical energy that is transferred through...
A
null
sciq
sciq_9764
What do we call the solid form of hydrocarbons?
[ "bauxite", "coal", "shale", "methane" ]
Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons . Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas.
B
null
sciq
sciq_1329
Which region of dna consists of one or more genes that encode the proteins needed for a specific function?
[ "chromosome", "mRNA", "antigen", "operon" ]
Regulation of transcription in prokaryotes typically involves operons. An operon is a region of DNA that consists of one or more genes that encode the proteins needed for a specific function. The operon also includes a promoter and an operator. The operator is a region of the operon where regulatory proteins bind. It i...
D
null
sciq
sciq_3019
Fertilization occurs if a sperm enters the egg while it is passing through what tube?
[ "fallopian", "vaginal", "ovarian", "anterior" ]
Fertilization occurs if a sperm enters the egg while it is passing through the fallopian tube. When this happens, the egg finally completes meiosis. This results in two daughter cells that are different in size. The smaller cell is called a polar body . It contains very little cytoplasm. It soon breaks down and disappe...
A
null
sciq
sciq_1963
What are small, icy objects that have very elliptical orbits around the sun?
[ "comets", "craters", "asteroids", "meteors" ]
Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earth’s history, comets may have brought water and other substances to Earth during collisions.
A
null
sciq
sciq_6104
What type electrical circuits have multiple paths the current may take?
[ "parallel", "single loop", "perpendicular", "serial" ]
Parallel electrical circuits have multiple paths the current may take.
A
null
sciq
sciq_11301
All the major landmasses moved together to form one supercontinent in which period?
[ "cambrian", "permian", "Cenozoic", "Mesozoic" ]
During the Permian Period, all the major landmasses moved together to form one supercontinent. The supercontinent has been named Pangaea. You can see how it looked in Figure below . At this time, temperatures were extreme and the climate became very dry. As a result, plants and animals evolved ways to cope with dryness...
B
null
sciq
sciq_7948
How many protons do all atoms of a particular element have in their nuclei?
[ "varying number", "same number", "zero", "three" ]
B
null
sciq
sciq_7649
Chromosomes consist of what material made up of strings of dna?
[ "mitochondria", "gray matter", "rna", "chromatin" ]
8.2 Chromatin Chromosomes consist of chromatin11 . This is made up of strings of DNA, which typically measure centimeters in length if stretched out. This DNA is wound around a histone12 core and organized into nucleosome13 s. The chromatin14 must be uncoiled for gene expression15 and replication16 . Chromosome microgr...
D
null
sciq
sciq_449
What is the term for the tube that carries sound waves into the ear?
[ "ear canal", "sound canal", "flap canal", "tone canal" ]
The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum.
A
null
sciq
sciq_2001
What term is used to describe the amount of space occupied by a sample of matter?
[ "growth", "volume", "liquid", "mass" ]
Volume is the amount of space occupied by a sample of matter.
B
null
sciq
sciq_4589
The ions in ionic compounds are arranged in rigid three-dimensional patterns called what?
[ "crystal lattices", "lattice groups", "core lattices", "pattern lattices" ]
The ions in ionic compounds are arranged in rigid three-dimensional patterns called crystal lattices. The crystal lattice that is formed is a characteristic property of a given compound.
A
null
sciq
sciq_7124
What are the three most common elements in the air we breathe?
[ "nitrogen, oxygen and argon", "oxygen, nitrogen, H20", "nitrogen, argon, hydrogen", "argon, oxygen, hydrogen" ]
Most nonmetals are poor conductors of heat. In fact, they are such poor conductors of heat that they are often used for insulation. For example, the down filling in this sleeping bag is full of air, which consists primarily of the nonmetal gases oxygen and nitrogen. These gases prevent body heat from escaping to the co...
A
null
sciq
sciq_10071
A basic function of cells includes obtaining what from glucose?
[ "acids", "food", "proteins", "energy" ]
Obtaining energy from glucose is one of the basic functions of cells. Another basic function of living cells is dividing.
D
null
sciq
sciq_773
What will the contraction of smooth muscles help organs do?
[ "carry out functions", "fine motor movements", "move across distances", "move joints" ]
Muscle tissue in the walls of internal organs such as the stomach and intestines is smooth muscle . When smooth muscle contracts, it helps the organs carry out their functions. For example, when smooth muscle in the stomach contracts, it squeezes the food inside the stomach, which helps break the food into smaller piec...
A
null
sciq
sciq_10658
Chains of small molecules called nucleotides make up what?
[ "proteins", "nucleic acids", "peptides", "chromosomes" ]
Nucleic acids consist of chains of small molecules called nucleotides, which are held together by covalent bonds. The structure of a nucleotide is shown in the Figure below . Each nucleotide consists of:.
B
null
sciq
sciq_3059
Some fish will be over-fished to the point that their species ceases to exist, which is also known as what?
[ "extinction", "endangered", "abundance", "accumulation" ]
will inevitably make it more difficult and costly to grow food. The world’s growing human population faces significant challenges in the increasing costs and other difficulties associated with producing food. Wild Food Sources In addition to growing crops and raising food animals, humans obtain food resources from wild...
A
null
sciq
sciq_5106
The iconic gray mantle of the human brain, which appears to make up most of the mass of the brain, is called?
[ "lobes", "thrombus", "cerebrum", "brain stem" ]
The Cerebrum The iconic gray mantle of the human brain, which appears to make up most of the mass of the brain, is the cerebrum (Figure 13.6). The wrinkled portion is the cerebral cortex, and the rest of the structure is beneath that outer covering. There is a large separation between the two sides of the cerebrum call...
C
null
sciq
sciq_8710
What gland is located in the neck, where it wraps around the trachea?
[ "salivary gland", "pituitary gland", "adrenal gland", "thyroid gland" ]
Figure 17.12 Thyroid Gland The thyroid gland is located in the neck where it wraps around the trachea. (a) Anterior view of the thyroid gland. (b) Posterior view of the thyroid gland. (c) The glandular tissue is composed primarily of thyroid follicles. The larger parafollicular cells often appear within the matrix of f...
D
null
sciq
sciq_5881
What substance causes oxidation by accepting electrons?
[ "enzymes", "oxidizing agent", "solvents", "thermal agent" ]
In the reaction above, the zinc is being oxidized by losing electrons. However, there must be another substance present that gains those electrons and in this case that is the sulfur. In other words, the sulfur is causing the zinc to be oxidized. Sulfur is called the oxidizing agent. The zinc causes the sulfur to gain ...
B
null
sciq
sciq_151
What are made from highly reflective metal that is applied to a curved or flat piece of glass?
[ "prisms", "mirrors", "kaleidoscopes", "lenses" ]
Mirrors are made from highly reflective metal that is applied to a curved or flat piece of glass. Converging mirrors can be used to focus light – headlights, telescopes, satellite TV receivers, and solar cookers all rely on this principle.
B
null
sciq
sciq_8708
Oysters require a certain minimum population density because they must be in close proximity to do this?
[ "replicate", "feed", "multiply", "reproduce" ]
The Chesapeake Bay (Figure 20.15a) is one of the most scenic areas on Earth; it is now in distress and is recognized as a case study of a declining ecosystem. In the 1970s, the Chesapeake Bay was one of the first aquatic ecosystems to have identified dead zones, which continue to kill many fish and bottomdwelling speci...
D
null
sciq
sciq_11597
What system of the body is responsible for ultimately ridding it of waste and excess water?
[ "excretory system", "digestive system", "respiratory system", "circulatory 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...
A
null
sciq
sciq_11071
What measures the amount of water in the air?
[ "humidity", "temperature", "cloud cover", "fire index" ]
Humidity is the amount of water in the air. Air with a high concentration of water will be called humid. Moving away from the most humid climate, biomes will be called semi-humid, semi-arid, or arid (the driest).
A
null
sciq
sciq_1561
What contain organelles common to other cells, such as a nucleus and mitochondria, and also have more specialized structures, including dendrites and axons?
[ "muscle cells", "follicles", "blood cells", "neurons" ]
Figure 16.19 Neurons contain organelles common to other cells, such as a nucleus and mitochondria. They also have more specialized structures, including dendrites and axons.
D
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sciq
sciq_7629
In which part of the ear are the vibrations amplified by the malleus, incus, and stapes?
[ "outer ear", "inner ear", "major ear", "middle ear" ]
D
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sciq
sciq_647
What is the plasma membrane mainly composed of?
[ "filaments", "phospholipids", "carbon", "antibodies" ]
The plasma membrane is composed mainly of phospholipids, which consist of fatty acids and alcohol. The phospholipids in the plasma membrane are arranged in two layers, called a phospholipid bilayer . As shown in Figure below , each phospholipid molecule has a head and two tails. The head “loves” water (hydrophilic) and...
B
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sciq
sciq_2006
Which theory explains how populations of organisms can change over time?
[ "changes by natural selection", "free by natural selection", "evolution by natural selection", "intelligent selection" ]
The theory of evolution by natural selection explains how populations of organisms can change over time. As environments change, so must the traits of organisms if they are to survive in the new conditions. Evolution by natural selection explains how this happens. It also explains why there are so many different specie...
C
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sciq
sciq_4424
What does photosynthesis change light energy into?
[ "carbon energy", "radiation energy", "chemical energy", "electrical energy" ]
Photosynthesis changes light energy to chemical energy. The chemical energy is stored in the bonds of glucose molecules. Glucose, in turn, is used for energy by the cells of almost all living things. Photosynthetic organisms such as plants make their own glucose. Other organisms get glucose by consuming plants (or orga...
C
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sciq
sciq_10908
How do plants and algae both make food?
[ "Digestion.", "atherosclerosis", "photosynthesis", "spermatogenesis" ]
Like plants, algae contain chlorophyll and make food by photosynthesis.
C
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sciq
sciq_234
Which form of electromagnetic waves have more energy: low frequency wave or high frequency waves?
[ "neither", "the same", "high frequency waves", "low frequency waves" ]
The energy of electromagnetic waves depends on their frequency. Low-frequency waves have little energy and are normally harmless. High-frequency waves have a lot of energy and are potentially very harmful.
C
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sciq
sciq_7790
What is transmitted that makes up the electromagnetic spectrum?
[ "light waves of different wavelengths", "sound waves of different frequencies", "gamma rays", "electromagnetic radiation in different wavelengths" ]
Electromagnetic radiation is energy transmitted as waves with different wavelengths. This makes up the electromagnetic spectrum.
D
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sciq
sciq_8307
How is blood supplied from the mother to the fetus?
[ "brain stem", "umbilical cord", "spinal cord", "vagina" ]
Hemoglobin of the Fetus The fetus has its own circulation with its own erythrocytes; however, it is dependent on the mother for oxygen. Blood is supplied to the fetus by way of the umbilical cord, which is connected to the placenta and separated from maternal blood by the chorion. The mechanism of gas exchange at the c...
B
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sciq
sciq_3879
Ultimately, the fluid that is lost from the blood vessels is returned through what system?
[ "symptomatic", "lymphatic", "venous", "urinary" ]
None of your blood vessels are leaking this badly, or you'd be in the hospital! But your blood vessels do leak a little bit. Water and solutes pass out of the blood vessels and help form the fluid that bathes your body's tissues. Ultimately the fluid that is lost from the blood vessels is returned through the lymphatic...
B
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sciq
sciq_6892
What are often formed biologically during the breakdown of proteins in animal cells, having the smell of death and decay?.
[ "ketones", "amines", "enzymes", "acids" ]
Amines generally have rather pungent or noxious odors. Ammonia can be considered the simplest amine and has a very distinctive odor. Methylamine has an unpleasant odor associated with dead fish. Amines are often formed biologically during the breakdown of proteins in animal cells, and so many have the smell of death an...
B
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sciq
sciq_265
What are formed by the attraction between oppositely charged ions?
[ "inept bonds", "soluble bonds", "magnetic bonds", "ionic bonds" ]
Ionic bonds are formed by the attraction between oppositely charged ions.
D
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sciq
sciq_6338
When something loses electrons, it must also?
[ "reduce protons", "slow down", "gain electrons", "gain protons" ]
Solution The charges, as well as the atoms, must balance in reactions. The silver atom is being oxidized from the 0 oxidation state to the 1+ state. Whenever something loses electrons, something must also gain electrons (be reduced) to balance the equation. Oxygen is a good oxidizing agent for these reactions because i...
C
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sciq
sciq_5790
What is electrons in the highest occupied principal energy level of an atom called?
[ "gradient electrons", "non-valence electrons", "shell electrons", "valence electrons" ]
In the study of chemical reactivity, we will find that the electrons in the outermost principal energy level are very important and so they are given a special name. Valence electrons are the electrons in the highest occupied principal energy level of an atom. In the second period elements listed above, the two electro...
D
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sciq
sciq_1730
What causes continents to drift closer to the poles or the equator?
[ "time", "plate movements", "plate tectonics", "earthquakes" ]
Plate movements cause continents to drift closer to the poles or the equator. Ocean currents also shift when continents drift. All these changes can affect Earth’s temperature.
B
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sciq
sciq_6221
What is the process by which organisms change in small ways over time?
[ "adaptation", "natural selection", "microevolution", "spontaneous mutation" ]
Microevolution is the process by which organisms change in small ways over time.
C
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sciq
sciq_10952
Between meals, when the level of blood glucose drops below a certain point, a signal is sent to what organ saying “make more glucose"?
[ "kidney", "pancreas", "liver", "brain" ]
Shortly after eating, there is a surplus of glucose in the body. Some of it will be used immediately, but the rest is stored in the form of glycogen. Between meals, when the level of glucose in the blood drops below a certain point, a signal is sent to the liver that says “make more glucose. ” In response, the glycogen...
C
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sciq
sciq_3459
What does pushing an object over the surface of a ramp cause?
[ "vibration", "Acceleration", "tension", "friction" ]
Consider the ramp in Figure below . It’s easier to push the heavy piece of furniture up the ramp to the truck than to lift it straight up off the ground. However, pushing the furniture over the surface of the ramp creates a lot of friction. Some of the force applied to moving the furniture must be used to overcome the ...
D
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sciq
sciq_3209
In frequency, the larger the air column, the larger the what?
[ "gravity", "mass", "wavelength", "absorption" ]
a) The water forms the bottom of the tube and thus where the node of the wave will be. Thus the air column is where the sound wave can exist. The larger the air column, the larger the wavelength. Frequency is inversely proportional to wavelength, thus the tube with the smallest air column will have the highest frequenc...
C
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sciq
sciq_434
In physics, what is defined as the average kinetic energy of the particles of matter?
[ "magnetism", "friction", "density", "temperature" ]
No doubt you already have a good idea of what temperature is. You might say that it’s how warm or cool something feels. In physics, temperature is defined as the average kinetic energy of the particles of matter. When particles of matter move more quickly, they have more kinetic energy, so their temperature is higher. ...
D
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sciq
sciq_5610
Carbonic anhydrase plays what role to achieve a variety of results involving different organs?
[ "enzyme", "inhibition", "blocker", "sequence" ]
About 67 percent of the water, Na+, and K+ entering the nephron is reabsorbed in the PCT and returned to the circulation. Almost 100 percent of glucose, amino acids, and other organic substances such as vitamins are normally recovered here. Some glucose may appear in the urine if circulating glucose levels are high eno...
A
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sciq
sciq_8628
Pulmonary ventilation in mammals occurs via what?
[ "inhalation", "inflammation", "osmosis", "ingestion" ]
Mammalian Systems In mammals, pulmonary ventilation occurs via inhalation (breathing). During inhalation, air enters the body through the nasal cavity located just inside the nose (Figure 39.7). As air passes through the nasal cavity, the air is warmed to body temperature and humidified. The respiratory tract is coated...
A
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sciq
sciq_8465
When the oval window vibrates, it causes what else to vibrate as well?
[ "hammer and anvil", "the cochlea", "timpani", "cilia" ]
The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny “hairs,...
B
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sciq
sciq_9243
What features of a salamander's skin help protect itself from predators ?
[ "slimy and camouflaged", "brightly colored and poisonous", "camouflaged and thin", "thick and impenetrable" ]
Salamanders have developed ways not to be eaten. Most salamanders have brightly colored, poisonous skin. The bold color tells predators not to eat the salamander. Many salamanders have glands on the back of the neck or on the tail that give off a poisonous or bad-tasting liquid. Some species can even shed their tail du...
B
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sciq
sciq_11507
A binary molecular compound is a molecular compound that is composed of what?
[ "four elements", "four atoms", "two 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 t...
D
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