question stringlengths 1 6.54k | choices listlengths 4 4 | answer stringclasses 4
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Like other amphibians, frogs generally lay their eggs in moist environments, which are required since the eggs lack what feature? | [
"nucleus",
"shells",
"tubes",
"membrane"
] | B | Frog eggs are fertilized externally, and like other amphibians, frogs generally lay their eggs in moist environments. A moist environment is required as eggs lack a shell and thus dehydrate quickly in dry environments. Frogs demonstrate a great diversity of parental behaviors, with some species laying many eggs and exh... | train | sciq | null |
What is the ratio of a wave frequency to its vibration frequency? | [
"two",
"one",
"three",
"same"
] | D | The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude... | train | sciq | null |
What is the hollow and muscular balloon-shaped organ that collects urine? | [
"kidney",
"prostate",
"urethra",
"urinary bladder"
] | D | The urinary bladder is a hollow and muscular organ. It is shaped a little like a balloon. It is the organ that collects urine. | train | sciq | null |
Sugars, starches, and cellulose are examples of what biochemical compounds that organisms use for energy? | [
"calories",
"prokaryotes",
"carbohydrates",
"proteins"
] | C | Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. | train | sciq | null |
During the embryonic stage of vertebrates, the notochord develops into what? | [
"backbone",
"rib cage",
"brain stem",
"umbilical cord"
] | A | Living chordates are mainly vertebrates. In vertebrates, the notochord develops into a backbone, or vertebral column, after the embryonic stage. A small percentage of chordates are invertebrates. Their notochord never develops into a backbone. Invertebrate chordates include tunicates and lancelets. Both groups of anima... | train | sciq | null |
What category of joints is immovable? | [
"sporozoans",
"amphiarthroses",
"diarthroses",
"synarthrosis"
] | D | Classification of Joints on the Basis of Function The functional classification divides joints into three categories: synarthroses, amphiarthroses, and diarthroses. A synarthrosis is a joint that is immovable. This includes sutures, gomphoses, and synchondroses. Amphiarthroses are joints that allow slight movement, inc... | train | sciq | null |
What do male cones in seed plants contain? | [
"nutrients",
"pollen",
"nitrogen",
"spores"
] | B | train | sciq | null | |
What kind of harm does a corrosive substance cause? | [
"Rust objects",
"eats through objects",
"Builds a crust",
"Attracts dust"
] | B | If a substance is corrosive, it can eat through objects. Many scientists have to work with chemicals that are corrosive or otherwise dangerous. That's one reason that following safety precautions in the laboratory or field is very important. | train | sciq | null |
Receptors for what chemical messengers recognize molecules with specific shapes and side groups, and respond only to those that are recognized? | [
"chromosomes",
"acids",
"enzymes",
"hormones"
] | D | Pathways of Hormone Action The message a hormone sends is received by a hormone receptor, a protein located either inside the cell or within the cell membrane. The receptor will process the message by initiating other signaling events or cellular mechanisms that result in the target cell’s response. Hormone receptors r... | train | sciq | null |
A hydraulic jack that makes it possible to lift a car easily is an example of what, meaning it produces mechanical advantages? | [
"simple machine",
"complex machines",
"simple weapon",
"quantum physics"
] | A | A person is able to lift the entire rear end of the automobile using only one hand with the hydraulic jack shown in the image. Hydraulic systems are similar to simple machines in that they can produce very large mechanical advantages. | train | sciq | null |
What process consists of the mechanisms that produce an observed pattern of change? | [
"evolution",
"variation",
"repetition",
"cycle"
] | A | train | sciq | null | |
Prokaryotic cells have a cell wall located outside of the __________? | [
"chromosomes",
"epidermis",
"chloroplasts",
"plasma membrane"
] | D | Prokaryotic cells have a cell wall outside their plasma membrane. | train | sciq | null |
Multiplying the linear momentum of a spinning object by the radius calculates what? | [
"angular momentum",
"applied momentum",
"total momentum",
"angular torque"
] | A | The angular momentum of a spinning object can be found in two equivalent ways. Just like linear momentum, one way, shown in the first equation, is to multiply the moment of inertia, the rotational analog of mass, with the angular velocity. The other way is simply multiplying the linear momentum by the radius, as shown ... | train | sciq | null |
What are responsible for removing excess h+ ions from the blood? | [
"stomach chambers",
"intestinal walls",
"kidneys",
"liver nodes"
] | C | The kidneys are responsible for removing excess H+ ions from the blood. If the kidneys fail, what would happen to blood pH and to hemoglobin affinity for oxygen? Factors That Affect Oxygen Binding The oxygen-carrying capacity of hemoglobin determines how much oxygen is carried in the blood. In addition to P O , 2 other... | train | sciq | null |
What makes up the dense outer layer of bones? | [
"compact bone",
"scales",
"cartilage",
"marrow"
] | A | Compact bone makes up the dense outer layer of bones. | train | sciq | null |
What refers to a substance made from two or more elements joined by chemical bonds? | [
"basic",
"contrast",
"compound",
"component"
] | C | In nature, elements rarely occur alone. Instead, they combine to form compounds. A compound is a substance composed of two or more elements joined by chemical bonds. For example, the compound glucose is an important body fuel. It is always composed of the same three elements: carbon, hydrogen, and oxygen. Moreover, the... | train | sciq | null |
Stress building up at the same rate over time at a fault causes what phenomenon? | [
"earthquakes",
"erosion",
"volcanoes",
"storms"
] | A | When an earthquake will occur is much more difficult to predict. Stress on a fault builds up at the same rate over time. So earthquakes should occur at regular intervals. But, so far, scientists cannot predict when quakes will occur even to within a few years. Around Parkfield, California, an earthquake of magnitude 6.... | train | sciq | null |
Materials made from non-living substances like pebbles and sand are called what? | [
"inorganic",
"fibrous",
"microscopic",
"organic"
] | A | Some of them are inorganic . Inorganic materials are made from non-living substances like pebbles and sand. | train | sciq | null |
What type of gas levels in the atmosphere are increasing? | [
"carbonate gas",
"helium gas",
"hydrogen gas",
"greenhouse gas"
] | D | Greenhouse gas levels in the atmosphere are increasing. Global temperatures are increasing. | train | sciq | null |
What is the earths crust composed of? | [
"sedimentary rock",
"bicellular rock",
"igneuos rock",
"metamorphic rock"
] | C | Like Earth, the Moon has a distinct crust, mantle, and core. The crust is composed of igneous rock. This rock is rich in the elements oxygen, silicon, magnesium, and aluminum. On the near side, the Moon’s crust is about 30 kilometers thick. On the far side, the crust is about 100 kilometers thick. The mantle is made of... | train | sciq | null |
Cells that are divided by oncogenes contain damaged what? | [
"dna",
"cells",
"atoms",
"bacteria"
] | A | Proto-oncogenes normally help control cell division. Mutations in these genes turn them into oncogenes. Oncogenes promote the division of cells with damaged DNA. | train | sciq | null |
When does exchange of dna segments happen between non-sister chromatids of homologous chromosomes? | [
"during mitosis",
"during diversion",
"during crossing-over",
"during meiosis"
] | C | During crossing-over, segments of DNA are exchanged between non-sister chromatids of homologous chromosomes. Notice how this can result in an allele (A) on one chromosome being moved to the other chromosome. The four chromatids compose the tetrad, with a chiasma at the point of exchange. | train | sciq | null |
What are observable patterns of stars found in the night sky called? | [
"deviations",
"latitudes",
"deformations",
"constellations"
] | D | Humans have been studying the night sky for thousands of years. Knowing the motions of stars helped people keep track of seasons. With this information they could know when to plant crops. Stars were so important that the patterns they made in the sky were named. These patterns are called constellations . Even now, con... | train | sciq | null |
If you were to filter out all the cells in blood, you would be left with what golden-yellow liquid? | [
"pus",
"hemoglobin",
"plasma",
"platelets"
] | C | If you were to filter out all the cells in blood, a golden-yellow liquid would be left behind. Plasma is this fluid part of the blood. Plasma is about 90% water and about 10% dissolved proteins, glucose, ions, hormones, and gases. Blood is made up mostly of plasma. | train | sciq | null |
The simplest organic compounds have hydrogen and what else? | [
"sodium",
"nitrogen",
"carbon",
"oxygen"
] | C | The simplest organic compounds are those composed of only two elements: carbon and hydrogen. These compounds are called hydrocarbons. Hydrocarbons themselves are separated into two types: aliphatic hydrocarbons and aromatic hydrocarbons. Aliphatic hydrocarbons are hydrocarbons based on chains of C atoms. There are thre... | train | sciq | null |
Temperature and what other environmental factor are important in the activity of an enzyme? | [
"color",
"shape",
"size",
"ph level"
] | D | train | sciq | null | |
What glands are wedges of glandular and neuroendocrine tissue adhering to the top of the kidneys by a fibrous capsule? | [
"nutrients glands",
"fatty glands",
"heart glands",
"adrenal glands"
] | D | 17.6 | The Adrenal Glands By the end of this section, you will be able to: • Describe the location and structure of the adrenal glands • Identify the hormones produced by the adrenal cortex and adrenal medulla, and summarize their target cells and effects The adrenal glands are wedges of glandular and neuroendocrine ti... | train | sciq | null |
What is the force that pulls downward on an object and is measured by weight? | [
"strength",
"light",
"gravity",
"work"
] | C | Weight measures the force of gravity pulling downward on an object. The SI unit for weight, like other forces, is the Newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 Newtons because of the pull of Earth’s gravity. On the moon, which has less gravity, the same mass would weigh less. Weight is measure... | train | sciq | null |
Which reproduction produces offspring genetically identical to the one parent? | [
"sexual",
"bsexual",
"microscopic",
"asexual"
] | D | That is the main difference between sexual and asexual reproduction. Sexual reproduction just means combining genetic material from two parents. Asexual reproduction produces offspring genetically identical to the one parent. | train | sciq | null |
Water in its solid state is commonly known as what? | [
"carbon dioxide",
"glass",
"sea",
"ice"
] | D | During the water cycle, water occurs in three different states: gas (water vapor), liquid (water), and solid (ice). Many processes are involved as water changes state in the water cycle. | train | sciq | null |
Besides the concentration of dissolve oxygen and nutrients in the water, what other factor limits aquatic organisms? | [
"temperature",
"rainfall",
"availability of sunlight",
"lake size"
] | C | Most aquatic organisms do not have to deal with extremes of temperature or moisture. Instead, their main limiting factors are the availability of sunlight and the concentration of dissolved oxygen and nutrients in the water. | train | sciq | null |
Which type of membrane are ribosomes surrounded by? | [
"none",
"partial",
"permenant",
"temporary"
] | A | Ribosomes are found in both eukaryotic and prokaryotic cells. Ribosomes are not surrounded by a membrane. The other organelles found in eukaryotic cells are surrounded by a membrane. | train | sciq | null |
Which scientist was responsible for the theory of evolution by natural selection? | [
"albert einstein",
"galileo Galilei",
"charles darwin",
"stephen hawking"
] | C | Linnaeus classified organisms based on obvious physical traits. Basically, organisms were grouped together if they looked alike. After Darwin published his theory of evolution in the 1800s (discussed in the following chapter), scientists looked for a way to classify organisms that showed phylogeny. Phylogeny is the evo... | train | sciq | null |
Soft cartilage gradually turns into hard bone through what process? | [
"elongation",
"ossification",
"calcification",
"oxidation"
] | B | Early in the development of a human fetus, the skeleton is made entirely of cartilage . The relatively soft cartilage gradually turns into hard bone through ossification . This is a process in which mineral deposits replace cartilage. As shown in Figure below , ossification of long bones, which are found in the arms an... | train | sciq | null |
Glycerol is a triol, an alcohol which contains three what? | [
"cytoplasm functional groups",
"stark functional groups",
"hydroxl acidic groups",
"hydroxl functional groups"
] | D | Glycerol is a triol, an alcohol which contains three hydroxyl functional groups. A fatty acid is a long carbon chain, generally from 12 to 24 carbons in length, with an attached carboxyl group. Each of the three fatty acid molecules undergoes an esterification with one of the hydroxyl groups of the glycerol molecule. T... | train | sciq | null |
The parts of the ears involved in balance are called what? | [
"symmetrical canals",
"rectangular canals",
"semicircular canals",
"lobe canal"
] | C | The parts of the ears involved in balance are the semicircular canals . Above, the semicircular canals are colored purple ( Figure above ). The canals contain liquid and are like the bottle of water pictured below ( Figure below ). When the bottle tips, the water surface moves up and down the sides of the bottle. When ... | train | sciq | null |
The sun’s heat can also be trapped in your home by using south facing windows and good what? | [
"curtains",
"vegetation",
"insulation",
"floors"
] | C | Solar energy is used to heat homes and water, and to make electricity. Scientists and engineers have many ways to get energy from the Sun ( Figure above ). One is by using solar cells. Solar cells are devices that turn sunlight directly into electricity. Lots of solar cells make up an individual solar panel. You may ha... | train | sciq | null |
Red blood cells do not perform aerobic respiration, but they do perform what process that is nearly universal to organisms? | [
"reproduction",
"glycolysis",
"digestion",
"mitosis"
] | B | CRITICAL THINKING QUESTIONS 18. Why is it beneficial for cells to use ATP rather than energy directly from the bonds of carbohydrates? What are the greatest drawbacks to harnessing energy directly from the bonds of several different compounds? 19. Nearly all organisms on earth carry out some form of glycolysis. How doe... | train | sciq | null |
Late adulthood begins in the mid-60s and continues until? | [
"adolescence",
"youth",
"death",
"birth"
] | C | Late adulthood begins in the mid-60s and continues until death. This is the stage of life when most people retire from work. This frees up their time for hobbies, grandchildren, or other interests. For example, the man in Figure below enjoys creating music in old age. | train | sciq | null |
The concentration of a substance is the quantity of solute present in a given quantity of ___________? | [
"salutation",
"solution",
"structure",
"mixture"
] | B | Summary The concentration of a substance is the quantity of solute present in a given quantity of solution. Concentrations are usually expressed as molarity, the number of moles of solute in 1 L of solution. Solutions of known concentration can be prepared either by dissolving a known mass of solute in a solvent and di... | train | sciq | null |
What is the study of rock strata called? | [
"biology",
"chemistry",
"stratigraphy",
"biochemistry"
] | C | The study of rock strata is called stratigraphy . The laws of stratigraphy can help scientists understand Earth’s past. The laws of stratigraphy are usually credited to a geologist from Denmark named Nicolas Steno. He lived in the 1600s. The laws are illustrated in the Figure below ; refer to the figure as you read abo... | train | sciq | null |
What is the particular sequence of amino acids in a longer chain called? | [
"amino acid sequence",
"molecular sequence",
"atomic sequence",
"carbon sequence"
] | A | The dipeptide has a free amino group on one end of the molecule and a free carboxyl group on the other end. Each is capable of extending the chain through the formation of another peptide bond. The particular sequence of amino acids in a longer chain is called an amino acid sequence. By convention, the amino acid seque... | train | sciq | null |
Stones, infections, and diabetes threaten the health and functioning of what paired organs? | [
"lungs",
"arteries",
"kidneys",
"tissues"
] | C | A person can live a normal, healthy life with just one kidney. However, at least one kidney must function properly to maintain life. Diseases that threaten the health and functioning of the kidneys include kidney stones, infections, and diabetes. | train | sciq | null |
What is the name of the outer layer of skin? | [
"the dermis",
"the epidermis",
"hypodermis",
"endodermis"
] | B | The epidermis is the outer layer of skin, consisting of epithelial cells and little else (see Figure below ). For example, there are no nerve endings or blood vessels in the epidermis. The innermost cells of the epidermis are continuously dividing through mitosis to form new cells. The newly formed cells move up throug... | train | sciq | null |
What is the major source of water vapor in the atmosphere? | [
"drift",
"sea",
"streams",
"ocean"
] | D | Oceans are the major source of water vapor in the atmosphere. Sunlight heats water near the sea surface ( Figure below ). As the water warms, some of it evaporates. The water vapor rises into the air, where it may form clouds and precipitation. Precipitation provides the freshwater needed by plants and other living thi... | train | sciq | null |
The release of mature eggs that occurs at the midpoint of each cycle is called? | [
"ovulation",
"fertilization",
"induction",
"semination"
] | A | train | sciq | null | |
What are the three ways to control the transcription of an operon? | [
"repressive, activator, spontaneous",
"hormonal, repressive, activator,",
"repressive, activator, inducible",
"transparent , activator , inducible"
] | C | 16.2 Prokaryotic Gene Regulation The regulation of gene expression in prokaryotic cells occurs at the transcriptional level. There are three ways to control the transcription of an operon: repressive control, activator control, and inducible control. Repressive control, typified by the trp operon, uses proteins bound t... | train | sciq | null |
Peroxisomes carry out oxidation reactions that break down what acids? | [
"stomach acids",
"fatty acids and amino acids",
"nitric acids",
"acetic acids"
] | B | Peroxisomes Peroxisomes are small, round organelles enclosed by single membranes. They carry out oxidation reactions that break down fatty acids and amino acids. They also detoxify many poisons that may enter the body. Alcohol is detoxified by peroxisomes in liver cells. A byproduct of these oxidation reactions is hydr... | train | sciq | null |
The magnitude of the momentum vector is the product of what two properties? | [
"mass and speed",
"acceleration and speed",
"volume and speed",
"work and speed"
] | A | Momentum is a vector that points in the direction of the velocity vector. The magnitude of this vector is the product of mass and speed. | train | sciq | null |
Hydrostatic skeletons are well suited for life in what kind of environments? | [
"surface",
"bacterial",
"aquatic",
"pelagic"
] | C | train | sciq | null | |
How do prokaryotic organisms reproduce asexually? | [
"residual fission",
"binary fission",
"kinetic fission",
"mitosis"
] | B | Prokaryotic organisms reproduce asexually by binary fission , a process that produces identical offspring ( Figure below ). In asexual reproduction , a single parent produces genetically identical offspring. As prokaryotes do not have a nucleus, and have only one circular chromosome, they do not need to reproduce by th... | train | sciq | null |
Many species use their body shape and coloration to avoid what? | [
"human contact",
"detection by predators",
"exposure",
"sunlight"
] | B | Many species use their body shape and coloration to avoid being detected by predators. The tropical walking stick is an insect with the coloration and body shape of a twig which makes it very hard to see when stationary against a background of real twigs (Figure 45.20a). In another example, the chameleon can change its... | train | sciq | null |
What property of ocean water increases rapidly as the water gets deeper? | [
"salt content",
"speed",
"pressure",
"visability"
] | C | The pressure of ocean water increases rapidly as the water gets deeper. | train | sciq | null |
Remember electrons are negatively charged, so ions with a positive charge have lost what? | [
"atom",
"proton",
"neutron",
"electron"
] | D | Solution First, write out the electron configuration for each parent atom. We have chosen to show the full, unabbreviated configurations to provide more practice for students who want it, but listing the coreabbreviated electron configurations is also acceptable. Next, determine whether an electron is gained or lost. R... | train | sciq | null |
What type of starch is used for long-term energy storage in animal cells? | [
"rigid",
"enzyme",
"glycogen",
"fructose"
] | C | Starches are one of the more common polysaccharides. Starch is made up of a mixture of amylose (15–20%) and amylopectin (80–85%). Amylose consists of a linear chain of several hundred glucose molecules and amylopectin is a branched molecule made of several thousand glucose units. Starches can be digested by hydrolysis ... | train | sciq | null |
What contracts to move food throughout the gastrointestinal tract? | [
"vessels",
"nerves",
"muscles",
"fluids"
] | C | waves of muscle contractions in the organs of the gastrointestinal tract that keep food moving through the tract. | train | sciq | null |
A magnet can exert force on objects without touching them, as long as they are within what? | [
"magnetic field",
"gravitational field",
"molecular field",
"audio field"
] | A | A familiar example may help you understand the vibrating electric and magnetic fields that make up electromagnetic waves. Consider a bar magnet, like the one in the Figure below . The magnet exerts magnetic force over an area all around it. This area is called a magnetic field. The field lines in the diagram represent ... | train | sciq | null |
What field of science seeks to explain how traits are passed on from one generation to the next? | [
"zoology",
"quantum physics",
"biochemistry",
"genetics"
] | D | Genetics is the study of inheritance. The field of genetics seeks to explain how traits are passed on from one generation to the next. | train | sciq | null |
Saturated hydrocarbons get their name because they are saturated with what atoms? | [
"helium",
"oxygen",
"nitrogen",
"hydrogen"
] | D | Saturated hydrocarbons have only single bonds between carbon atoms, so the carbon atoms are bonded to as many hydrogen atoms as possible. In other words, they are saturated with hydrogen atoms. | train | sciq | null |
What is the name of the black opening in the eye that lets light enter? | [
"inlet",
"iris",
"cornea",
"pupil"
] | D | Next, light passes through the pupil. The pupil is a black opening in the eye that lets light enter the eye. | train | sciq | null |
Enzymes in saliva help bread down and digest what? | [
"fiber and minerals",
"water and fiber",
"starches and water",
"starches and fats"
] | D | Figure 16.5 (a) Digestion of food begins in the mouth. (b) Food is masticated by teeth and moistened by saliva secreted from the salivary glands. Enzymes in the saliva begin to digest starches and fats. With the help of the tongue, the resulting bolus is moved into the esophagus by swallowing. (credit: modification of ... | train | sciq | null |
What comes first in the life cycle of a plant? | [
"garden",
"seed",
"flower",
"pair"
] | B | train | sciq | null | |
Within the chloroplast, synthesis of what takes place in the fluid inside the inner membrane called the stroma? | [
"glucose",
"wheat",
"fructose",
"sugar"
] | D | Figure 4.17 The chloroplast has an outer membrane, an inner membrane, and membrane structures called thylakoids that are stacked into grana. The space inside the thylakoid membranes is called the thylakoid space. The light harvesting reactions take place in the thylakoid membranes, and the synthesis of sugar takes plac... | train | sciq | null |
When referring to genes, what term describes the property of having multiple phenotypic effects? | [
"xerophyte",
"pleiotrophy",
"archetype",
"prototype"
] | B | Many genes have multiple phenotypic effects, a property called pleiotropy. | train | sciq | null |
What are intervertebral discs made of? | [
"intercartilage",
"fibrocartilage",
"fibrotissue",
"connective cartilage"
] | B | Figure 9.3 Intervertebral Disc An intervertebral disc unites the bodies of adjacent vertebrae within the vertebral column. Each disc allows for limited movement between the vertebrae and thus functionally forms an amphiarthrosis type of joint. Intervertebral discs are made of fibrocartilage and thereby structurally for... | train | sciq | null |
What harmful light does ozone reduce in the upper atmospheres? | [
"ultraviolet light",
"specific light",
"visible light",
"infrared light"
] | A | The ozone in smog is also harmful to human health. The image below shows the levels of ozone to watch out for ( Figure below ). Some people are especially sensitive to ozone. They can be harmed by levels of ozone that would not affect most other people. These people include those with lung or heart problems. | train | sciq | null |
What device detects and measuresee earthquake waves? | [
"sphygmomanometer",
"polygraph",
"stenograph",
"seismograph"
] | D | Although the idea that Earth is a magnet is centuries old, the discovery of why Earth is a magnet is a relatively new. In the early 1900s, scientists started using seismographic data to learn about Earth’s inner structure. A seismograph detects and measure earthquake waves. Evidence from earthquakes showed that Earth h... | train | sciq | null |
While some climate regions have multiple layers, arid regions are poor for development of what? | [
"soil",
"rain",
"minerals",
"plants"
] | A | Not all climate regions develop soils. Arid regions are poor at soil development. Not all regions develop the same soil horizons. Some areas develop as many as five or six distinct layers. Others develop only a few. | train | sciq | null |
Some plants open their leaves during the day to collect what? | [
"energy",
"sunlight",
"moisture",
"precipitation"
] | B | Plants also detect and respond to the daily cycle of light and darkness. For example, some plants open their leaves during the day to collect sunlight and then close their leaves at night to prevent water loss. | train | sciq | null |
What secretion initiates chemical digestion while also protecting the oral cavity? | [
"lymph",
"stomach acid",
"mucus",
"saliva"
] | D | train | sciq | null | |
What makes echinoderms force water into the feet and move forward? | [
"field contractions",
"spring contractions",
"muscle contractions",
"vacuum contractions"
] | C | A unique feature of echinoderms is their water vascular system . This is a network of canals that extend along each body part. In most echinoderms, the canals have external projections called tube feet (see Figure below ). The feet have suckers on the ends. Muscle contractions force water into the feet, causing them to... | train | sciq | null |
Red blood cells, white blood cells, and platelets are all produced where? | [
"in synovial fluid",
"in red marrow",
"in collagen",
"in yellow marrow"
] | B | energy. Red marrow is where hematopoiesis—the production of blood cells—takes place. Red blood cells, white blood cells, and platelets are all produced in the red marrow. | train | sciq | null |
Fine-grained mud in the deep ocean comes from silts and clays brought from the land by? | [
"fire",
"waves",
"water",
"wind"
] | D | Fine-grained mud in the deep ocean comes from silts and clays brought from the land by wind. The particles are deposited on the sea surface. they slowly settle to the deep ocean floor, forming brown, greenish, or reddish clays. Volcanic ash may also settle on the seafloor. | train | sciq | null |
Pseudopods are temporary extensions of what? | [
"cytopods",
"the cell wall",
"the cytoplasm",
"the mucus"
] | C | Almost all protozoa can move. They have special appendages for this purpose. You can see different types in Figure below . Cilia (cilium, singular) are short, hair-like projections. Pseudopods are temporary extensions of the cytoplasm. Flagella are long, whip-like structures. Flagella are also found in most prokaryotes... | train | sciq | null |
Ice cubes in cola cause the cola to lose what? | [
"mechanical energy",
"gravity",
"thermal energy",
"kinetic energy"
] | C | Simon Cousins. Ice cubes in cola cause the cola to lose thermal energy . CC BY 2.0. | train | sciq | null |
How are protists traditionally classified? | [
"animal-like, plant-like, or fungi-like",
"carnivorous or herbivorous",
"sponges, fungi and bacteria",
"organic and inorganic"
] | A | Protists are traditionally classified as animal-like, plant-like, or fungi-like. You will read more about each of these types of protists in the next lesson. | train | sciq | null |
Coal is a solid hydrocarbon formed from what type of decaying material? | [
"soil",
"mammals",
"plant",
"insects"
] | C | Coal is a solid hydrocarbon formed from decaying plant material over millions of years. | train | sciq | null |
Many disciplines within the study of biology contribute to understanding how past and present life evolved over time; these disciplines together contribute to building, updating, and maintaining this? | [
"forests of life",
"amount of life",
"root of life",
"tree of life"
] | D | The diagrams above can serve as a pathway to understanding evolutionary history. The pathway can be traced from the origin of life to any individual species by navigating through the evolutionary branches between the two points. Also, by starting with a single species and tracing back towards the "trunk" of the tree, o... | train | sciq | null |
A flow of one coulomb per second is called one ampere, which is a measure of what? | [
"powered current",
"Direct current",
"performance current",
"electric current"
] | D | The electric current is measured in coulombs per second. A flow of one coulomb per second is called one ampere, A, of current. | train | sciq | null |
What might eventually happen to a species if it is unable to reproduce? | [
"migration",
"adaptation",
"natural selection",
"extinction"
] | D | train | sciq | null | |
What do muscles need to contract? | [
"stimulus",
"stress",
"tendons",
"pressures"
] | A | Muscles cannot contract on their own. They need a stimulus from a nerve cell to “tell” them to contract. Let’s say you decide to raise your hand in class. Your brain sends electrical messages to nerve cells, called motor neurons, in your arm and shoulder. The motor neurons, in turn, stimulate muscle fibers in your arm ... | train | sciq | null |
What is considered to be a unique feature of echinoderms? | [
"oil vascular system",
"iron vascular system",
"water vascular system",
"air vascular system"
] | C | A unique feature of echinoderms is their water vascular system. This is a network of canals that extends along each body part. In most echinoderms, the canals have external projections called tube feet (see Figure below ). The feet have suckers on the ends. Muscle contractions force water into the feet, causing them to... | train | sciq | null |
Noninfectious diseases can't be passed from one person to another. instead, these types of diseases are caused by factors such as environment, genetics and what? | [
"lifestyle",
"age",
"education",
"weight"
] | A | Noninfectious diseases can't be passed from one person to another. Instead, these types of diseases are caused by factors such as the environment, genetics, and lifestyle. Examples of inherited noninfectious conditions include cystic fibrosis and Down syndrome. If you're born with these conditions, you must learn how t... | train | sciq | null |
What 'counting' instrument is used to measure radioactivity? | [
"ellie counter",
"geiger counter",
"pryor counter",
"Liquid Counter"
] | B | prepared. A student measures the radioactivity of this source with a Geiger counter and observes 1500 counts per minute. She notices that the source was prepared 120 days before her lab. What fraction of the decays is she observing with her apparatus? (b) Identify some of the reasons that only a fraction of the α s emi... | train | sciq | null |
Often primary producers, what term describes species considered the “base” or “bedrock” of a community, having the greatest influence on its overall structure? | [
"fundamental",
"consumable",
"primary",
"foundation"
] | D | Foundation Species Foundation species are considered the “base” or “bedrock” of a community, having the greatest influence on its overall structure. They are often primary producers, and they are typically an abundant organism. For example, kelp, a species of brown algae, is a foundation species that forms the basis of... | train | sciq | null |
Hurricanes that form in the tropics are called what? | [
"tornados",
"rain cyclones",
"caribbean cyclones",
"tropical cyclones"
] | D | Hurricanes are cyclones. Since they form in the tropics, they are called tropical cyclones. These storms form over very warm ocean water in summer and autumn. The temperature of the sea surface must be 28 o C (82 o F) or higher. The air above the water warms and rises. This forms a low pressure cell. The air begins to ... | train | sciq | null |
What types of flat maps show users changes in land elevation? | [
"atlases",
"topographic maps",
"surveyor maps",
"elliptical maps"
] | B | Topographic maps are flat maps that show the three-dimensional surface features of an area. Topographic maps help users see the how the land changes in elevation. | train | sciq | null |
Sister chromatids separate as part of anaphase in what process? | [
"osmosis",
"mitosis",
"angiogenesis",
"vesicles"
] | B | train | sciq | null | |
Vertebrates evolved from primitive forms of which creature? | [
"chordates",
"arthropods",
"humanoids",
"cephalopods"
] | A | Vertebrates evolved from primitive chordates. This occurred about 550 million years ago. The earliest vertebrates may have been jawless fish, like the hagfish in Figure below . Vertebrates evolved a backbone to replace the notochord after the embryo stage. They also evolved a cranium , or bony skull, to enclose and pro... | train | sciq | null |
Another name for table salt is? | [
"hydrogen chloride",
"dioxide chloride",
"sodium chloride",
"carbon chloride"
] | C | The table salt pictured in the Figure below contains two elements that are so reactive they are rarely found alone in nature. Instead, they undergo chemical reactions with other elements and form compounds. Table salt is the compound named sodium chloride (NaCl). It forms when an atom of sodium (Na) gives up an electro... | train | sciq | null |
In iceland, the mid-atlantic ridge is above sea what? | [
"tide",
"atmosphere",
"level",
"bottom"
] | C | In Iceland, the Mid-Atlantic Ridge is above sea level. It's the only place we can see a mid-ocean ridge out of the water. The Midlina Bridge connects two plates. On the west side is the North American plate. On the east side is the Eurasian plate. A mid-ocean ridge is where new crust is created. Eventually this spot wi... | train | sciq | null |
The earth's atmosphere, climate, and living things are effected by what feature that covers more than 70 percent of earth's surface? | [
"oceans",
"mountains",
"continents",
"rivers"
] | A | Oceans cover more than 70 percent of Earth's surface and hold 97 percent of its 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. | train | sciq | null |
What is the nest of cell an egg rests in called? | [
"follicle",
"mitochondria",
"pod",
"epidermis"
] | A | After puberty, an egg develops in an ovary about once a month. As you can see in Figure below , the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. | train | sciq | null |
The energy of a wave depends on time as well as what other property of the wave? | [
"amplitude",
"force",
"frequency",
"power"
] | A | The energy effects of a wave depend on time as well as amplitude. For example, the longer deep-heat ultrasound is applied, the more energy it transfers. Waves can also be concentrated or spread out. Sunlight, for example, can be focused to burn wood. Earthquakes spread out, so they do less damage the farther they get f... | train | sciq | null |
Genetic equilibrium occurs when what process doesn't exist within the population? | [
"evolution",
"reproduction",
"movement",
"variation"
] | A | The Hardy-Weinberg model describes how a population can remain at genetic equilibrium , referred to as the Hardy-Weinberg equilibrium. Genetic equilibrium occurs when there is no evolution within the population. In other words, the frequency of alleles (variants of a gene) will be the same from one generation to anothe... | train | sciq | null |
During meiosis, each parent synthesizes gametes that contain only half of their complement of what? | [
"receptors",
"neutrons",
"chromosomes",
"atoms"
] | C | The Chromosomal Theory of Inheritance was consistent with Mendel’s laws and was supported by the following observations: • During meiosis, homologous chromosome pairs migrate as discrete structures that are independent of other chromosome pairs. • The sorting of chromosomes from each homologous pair into pre-gametes ap... | train | sciq | null |
What is evolution that occurs over a long period of time called? | [
"macroevolution",
"catabolism",
"spontaneous mutation",
"introgression"
] | A | Evolution that occurs over a long period of time is called macroevolution . It might take place over millions of years. This scale of evolution occurs above the level of the species. Fossils provide evidence for evolution at this scale. The evolution of the horse family, shown in Figure below , is an example of macroev... | train | sciq | null |
What is the plasma membrane formed by? | [
"cholesterol byproduct",
"single lipid layer",
"a cytoplasm bilayer",
"a phospholipid bilayer"
] | D | The plasma membrane is formed by a phospholipid bilayer. | train | sciq | null |
What is formed when an element gains one or more electrons? | [
"ion",
"neutron",
"cation",
"anion"
] | D | When an element gains one or more electrons, an anion is formed. Nonmetals typically become anions when they interact with other chemical species. | train | sciq | null |
What is the term for the slow wearing down of rocks on earth’s surface? | [
"experiencing",
"evaporation",
"weathering",
"slipping"
] | C | Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earth’s surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it e... | train | sciq | null |
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