question
stringlengths
1
6.54k
choices
listlengths
4
4
answer
stringclasses
4 values
rationale
stringlengths
0
22.5k
split
stringclasses
1 value
dataset
stringclasses
6 values
subject
stringclasses
1 value
Both energy and heat can be expressed in units of what?
[ "amperes", "ohms", "joules", "velocities" ]
C
Energy and heat are expressed in units of joules.
train
sciq
null
In fact, when sitting in the sun, many ectothermic lizards have higher body temperatures than what?
[ "insects", "mammals", "carnivores", "primates" ]
B
train
sciq
null
In binary fission how many times does a cell split?
[ "one", "four", "six", "two" ]
D
In binary fission, a cell splits in two. First, the large circular chromosome is copied. Then the cell divides to form two new daughter cells. Each has a copy of the parent cell's chromosome.
train
sciq
null
What do nonvascular plants reproduce with?
[ "spores", "toxins", "photosynthesis", "vascular plants" ]
A
Nonvascular plants are low-growing, reproduce with spores, and need a moist habitat.
train
sciq
null
The most powerful or influential individual in a group is sometimes called what?
[ "beta", "dominant", "superior", "gamma" ]
B
The most powerful or influential individual in a group is sometimes called dominant. In genetics, a dominant trait means nearly the same thing. A dominant trait is the most influential trait and masks the other trait.
train
sciq
null
What is the first stage of cellular respiration?
[ "photosynthesis", "hydrolysis", "amniocentesis", "glycolysis" ]
D
train
sciq
null
In which direction does heat always flow through objects?
[ "from left to right", "from hotter to cooler", "from low to high", "from cooler to hotter" ]
B
The objects are at different temperatures, and heat flows from the hotter to the cooler object. This is always.
train
sciq
null
Like sharks, nearly the entire human skeleton during a specific pre-birth developmental stage is made of what connective tissue?
[ "cartilage", "phloem", "chloroplasm", "collagen" ]
A
Cartilage Cartilage is a connective tissue with a large amount of the matrix and variable amounts of fibers. The cells, called chondrocytes, make the matrix and fibers of the tissue. Chondrocytes are found in spaces within the tissue called lacunae. A cartilage with few collagen and elastic fibers is hyaline cartilage,...
train
sciq
null
When this forms underground, volcanoes rise?
[ "soil", "pumice", "CO2", "magma" ]
D
Volcanoes rise where magma forms underground. Volcanoes are found at convergent plate boundaries and at hotspots. Volcanic activity is found at divergent plate boundaries. The map in Figure below shows where volcanoes are located.
train
sciq
null
Hormones produced by what gland in the neck increase the rate of metabolism in cells throughout the body?
[ "thyroid", "pituitary", "thymus", "kidney" ]
A
The thyroid gland is a large gland in the neck. Thyroid hormones increase the rate of metabolism in cells throughout the body. They control how quickly cells use energy and make proteins.
train
sciq
null
When the ventricles begin to contract, pressure within the ventricles rises and blood flows toward the area of lowest pressure, which is initially in the atria. this backflow causes the cusps of the tricuspid and mitral (bicuspid) valves to close. these valves are tied down to the papillary muscles by these?
[ "photoreactive tendineae", "chollphyide tendineae", "chordae tendineae", "choanocyte tendineae" ]
C
When the ventricles begin to contract, pressure within the ventricles rises and blood flows toward the area of lowest pressure, which is initially in the atria. This backflow causes the cusps of the tricuspid and mitral (bicuspid) valves to close. These valves are tied down to the papillary muscles by chordae tendineae...
train
sciq
null
What is the skin of most reptiles covered with?
[ "hairs", "pores", "scales", "cuticle" ]
C
Reptiles have several adaptations for living on dry land that amphibians lack. For example, as shown in Figure below , the skin of most reptiles is covered with scales. The scales are made of very tough keratin, and they protect reptiles from injury, and also prevent them from losing water.
train
sciq
null
Gasoline, natural gas, fuel oil, diesel fuel, jet fuel, coal, kerosene, and propane are examples of what type of fule?
[ "polymerization fuel", "nuclear fue", "electrolysis fuel", "hydrocarbon fuel" ]
D
It is hard to overstate the importance of hydrocarbons to modern life. Hydrocarbons have even been called the “driving force of western civilization. ” You saw some ways they are used in the opening image. Several other ways are pictured in the Figure below . The most important use of hydrocarbons is for fuel. Gasoline...
train
sciq
null
Nearly all life processes depend on what substance, which is involved in biochemical reactions?
[ "hydrocarbons", "water", "air", "food" ]
B
Water is involved in many other biochemical reactions. As a result, just about all life processes depend on water. Clearly, life as we know it could not exist without water.
train
sciq
null
What has increased in the atmosphere throughout the history of the earth?
[ "oxygen", "nitrogen", "wind", "carbon" ]
A
Oxygen has increased in the atmosphere throughout the history of the earth. Note the logarithmic scale, which indicates great increases after first photosynthesis (in bacteria) and then land plants evolved. Related geological events: A = no oxidized iron; B = oxidized iron bands in seabed rock - evidence for O 2 in the...
train
sciq
null
Which two states of matter have definite volumes?
[ "GAS AND LIQUIDS", "bacteria and liquids", "contrasts and liquids", "solids and liquids" ]
D
Ice, water, and steam appear quite differently to the eye. If you were to look at these three states of matter on the molecular level, you would see that the arrangement of molecules is very different here as well. However, solids and liquids have definite volumes, unlike gases which tend to take on the shape of their ...
train
sciq
null
Tendon, cartilage, and bone are examples of what type of tissue that supports and binds other tissues of the body?
[ "muscular tissue", "repetitive tissue", "untreated tissue", "connective tissue" ]
D
Connective tissue is made up of many different types of cells that are all involved in supporting and binding other tissues of the body. Examples include tendon, cartilage, and bone. Blood is also classified as a specialized connective tissue.
train
sciq
null
What is the sac-like organ at the end of the esophagus?
[ "rectum", "stomach", "appendix", "larynx" ]
B
The stomach is a sac-like organ at the end of the esophagus. It has thick muscular walls. The muscles contract and relax. This moves the food around and helps break it into smaller pieces. Mixing the food around with the enzyme pepsin and other chemicals helps digest proteins.
train
sciq
null
Which class of acids acetic acid (ch 3 cooh) belongs to?
[ "strong acids", "common acids", "anorganic acids", "organic acids" ]
D
Not all hydrogen atoms in molecular compounds are ionizable. In methane (CH 4 ), the hydrogen atoms are covalently bonded to carbon in bonds that are only slightly polar. The hydrogen atoms are not capable of ionizing and methane has no acidic properties. Acetic acid (CH 3 COOH) belongs to a class of acids called organ...
train
sciq
null
What happens to the total energy of the system when heat is positive?
[ "it decreases", "it remains constant", "it increases", "nothing" ]
C
When heat is positive, the total energy of the system is increasing.
train
sciq
null
What type of species can alternate between medusa and polyp forms?
[ "cnidarian", "crocodilian", "mollusks", "chordata" ]
A
As you can see in Figure below , both body plans have radial symmetry. Some cnidarian species alternate between medusa and polyp forms. Other species exist in just one form or the other.
train
sciq
null
Extensive and intensive are categories of properties that apply to what?
[ "volume", "matter", "height", "weight" ]
B
Properties of matter fall into one of two categories. If the property depends on the amount of matter present, it is an extensive property. The mass and volume of a substance are examples of extensive properties; for instance, a gallon of milk has a larger mass and volume than a cup of milk. The value of an extensive p...
train
sciq
null
The vertebrate circulatory system enables blood to deliver ________ and remove wastes throughout the body.
[ "hydrogen and nutrients", "acid and nutrients", "oxygen and nutrients", "fluid and nutrients" ]
C
train
sciq
null
By what kind of change can a chemical change be reversed?
[ "another chemical change", "another radioactive change", "another carbon change", "another thermal change" ]
A
Because chemical changes result in different substances, they often cannot be undone. Some chemical changes can be reversed, but only by other chemical changes.
train
sciq
null
Earthquakes at convergent plate boundaries mark the location of the what?
[ "abducting lithosphere", "speeding lithosphere", "subducting lithosphere", "shorting lithosphere" ]
C
Earthquakes at convergent plate boundaries mark the location of the subducting lithosphere. The motion of the lithosphere as it plunges through the mantle causes the quakes ( Figure below ). At greater depths, the plate heats up enough to deform plastically.
train
sciq
null
New seafloor forms when what object cools?
[ "debris", "rain", "ash", "lava" ]
D
The seafloor spreading hypothesis brought all of these observations together in the early 1960s. Hot mantle material rises up at mid-ocean ridges. The hot magma erupts as lava. The lava cools to form new seafloor. Later, more lava erupts at the ridge. The new lava pushes the seafloor that is at the ridge horizontally a...
train
sciq
null
What are groups of atoms that behave as a single unit called?
[ "molecules", "protons", "particles", "ions" ]
A
Molecules are groups of atoms that behave as a single unit.
train
sciq
null
Hormones cause cellular changes by binding to receptors on these?
[ "able cells", "reach cells", "fighter cells", "target cells" ]
D
37.2 How Hormones Work Hormones cause cellular changes by binding to receptors on target cells. The number of receptors on a target cell can increase or decrease in response to hormone activity. Hormones can affect cells directly through intracellular hormone receptors or indirectly through plasma membrane hormone rece...
train
sciq
null
Food provides what type of energy needed by organisms, which is stored in bonds?
[ "radiation energy", "caffeine", "chemical energy", "calories" ]
C
The chemical energy that organisms need comes from food. Food consists of organic molecules that store energy in their chemical bonds. In terms of obtaining food for energy, there are two types of organisms: autotrophs and heterotrophs.
train
sciq
null
Catabolic reactions involve breaking what?
[ "metals", "bonds", "molecules", "levels" ]
B
Catabolic reactions involve breaking bonds. Larger molecules break down to form smaller ones. These reactions release energy. For example, energy is released when starches break down to sugars.
train
sciq
null
Scientists explain the world based on what?
[ "changes", "observations", "patterns", "theories" ]
B
Such knowledge of the natural world is only part of what science is. Science is as much about doing as knowing. Science is a way of learning about the natural world that depends on evidence, reasoning, and repeated testing. Scientists explain the world based on their observations. If they develop new ideas about the wa...
train
sciq
null
What is the general name for saturated hydrocarbons?
[ "enzymes", "petrolatums", "alkanes", "halides" ]
C
Saturated hydrocarbons are given the general name of alkanes . The name of specific alkanes always ends in - ane . The first part of the name indicates how many carbon atoms each molecule of the alkane has. The smallest alkane is methane. It has just one carbon atom. The next largest is ethane, with two carbon atoms. T...
train
sciq
null
Changing electric and mnagnetic fields radiate outward when?
[ "firing particles accelerate", "charged particles accelerate", "particles multiply", "particles lose their charge" ]
B
When charged particles accelerate , changing electric and magnetic fields radiate outward. The traveling electric and magnetic fields of an accelerating (often oscillating) charged particle are known as electromagnetic radiation or light.
train
sciq
null
What significant part of the cell do prokaryotic cells lack?
[ "a ribosome", "a nucleus", "a cell wall", "mitochondrial dna" ]
B
Prokaryotic cells are cells that lack a nucleus. The DNA in prokaryotic cells is in the cytoplasm, rather than enclosed within a nuclear membrane. All the organisms in the Bacteria and Archaea Domains have prokaryotic cells. No other organisms have this type of cell. Organisms with prokaryotic cells are called prokaryo...
train
sciq
null
Where do ectotherms get most of their heat?
[ "internally", "food", "metabolism", "external sources" ]
D
train
sciq
null
What layer is above the mesosphere?
[ "ionosphere", "exosphere", "stratosphere", "thermosphere" ]
D
The thermosphere is the layer above the mesosphere. It rises to 600 kilometers (372 miles) above the surface. The International Space Station orbits Earth in this layer as in Figure below .
train
sciq
null
What is produced by leydig cells in the embryonic testis and stimulates the development of male sexual organs?
[ "testosterone", "estrogen", "insulin", "androgen" ]
A
27.3 Development of the Male and Female Reproductive Systems The reproductive systems of males and females begin to develop soon after conception. A gene on the male’s Y chromosome called SRY is critical in stimulating a cascade of events that simultaneously stimulate testis development and repress the development of f...
train
sciq
null
What is a continuous flow of electric charges called?
[ "circuit", "electricity", "magnetic current", "electric current" ]
D
Electric current is a continuous flow of electric charges. Current is measured as the amount of charge that flows past a given point in a certain amount of time. The SI unit for electric current is the ampere (A), or amp. Electric current may flow in just one direction, or it may keep reversing direction.
train
sciq
null
What causes high winds and monsoon storms in the desert?
[ "low winter temperature", "moderate spring temperature", "and-12 summer temperature", "high summer temperature" ]
D
High summer temperatures on the desert create high winds and monsoon storms. Strong winds in the desert can pick up dust and blow it around. A dust storm known as a haboob ( Figure below ) forms in the downdrafts on the front of a thunderstorm.
train
sciq
null
What are the three most common protective devices?
[ "fuses, circuit breaks & surge protectors", "tranistors, resistors & diodes", "fuses , fabrication breaks & surge protectors", "fuses , circuit breaks & surge claws" ]
A
There are multiple ways to prevent these situations from occurring. The three most common protective devices are fuses, circuit breakers, and surge protectors.
train
sciq
null
Which veins return oxygen-rich blood from the lungs to the heart?
[ "varicose", "pulmonary", "jugular", "respiratory" ]
B
Today in many countries, death rates have gone down but birth rates remain high. This means that the population is growing. Figure below shows the growth rates of human populations all over the world.
train
sciq
null
Makemake and pluto are classified as what type of celestial object?
[ "nebula", "gas giants", "dwarf planets", "black holes" ]
C
Makemake is the third-largest and second-brightest dwarf planet we have discovered so far ( Figure below ). Makemake is only 75 percent the size of Pluto. Its diameter is between 1300 and 1900 kilometers. The name comes from the mythology of the Eastern Islanders. Makemake was the god that created humanity. At a distan...
train
sciq
null
What do you call the entire range of wavelengths of electromagnetic waves?
[ "electromagnetic spectrum", "molecular spectrum", "electric spectrum", "gaseous spectrum" ]
A
Sunlight contains the complete range of wavelengths of electromagnetic waves. The entire range is called the electromagnetic spectrum.
train
sciq
null
Joules and calories are the units of what?
[ "weight and energy", "energy and heat", "heat and velocity", "mass and potential" ]
B
Joules and calories are the units of energy and heat.
train
sciq
null
The brain and spinal cord are part of what system?
[ "immune system", "cardiovascular system", "digestive system", "central nervous system" ]
D
The brain and spinal cord make up the central nervous system.
train
sciq
null
The two parathyroid glands are located behind what gland?
[ "hypothalmus", "pituitary gland", "thymus", "thyroid" ]
D
The two parathyroid glands are located behind the thyroid gland. Parathyroid hormone helps keep the level of calcium in the blood within a narrow range. It stimulates bone cells to dissolve calcium in bone matrix and release it into the blood.
train
sciq
null
Fission is a method of what type of reproduction exhibited by some planarians?
[ "propagation", "sexual", "asexual", "spawning" ]
C
train
sciq
null
The best method for preparing pure phosphorous acid is by hydrolyzing what?
[ "carbon trichloride", "phosphorus trichloride", "dioxide trichloride", "dioxide phosphat" ]
B
Dilution of the products with water, followed by filtration to remove calcium sulfate, gives a dilute acid solution contaminated with calcium dihydrogen phosphate, Ca(H2PO4)2, and other compounds associated with calcium phosphate rock. It is possible to prepare pure orthophosphoric acid by dissolving P4O10 in water. Th...
train
sciq
null
What bonds result from the overlap of atomic orbitals?
[ "covalents", "metallic", "hydrogen", "valent" ]
A
Covalent bonds result from the overlap of atomic orbitals.
train
sciq
null
What is a cluster of neuron cell bodies in the pns called?
[ "gangnem", "ganglion", "crystals", "groupilion" ]
B
Regardless of the appearance of stained or unstained tissue, the cell bodies of neurons or axons can be located in discrete anatomical structures that need to be named. Those names are specific to whether the structure is central or peripheral. A localized collection of neuron cell bodies in the CNS is referred to as a...
train
sciq
null
Unlike the passive form, the sodium-potassium pump uses what type of transport?
[ "High", "active", "phase", "Low" ]
B
Mariana Ruiz Villarreal (User:LadyofHats/Wikimedia Commons), modified by Hana Zavadska. The sodium-potassium pump uses active transport . Public Domain.
train
sciq
null
On insects, what are the openings on the sides of the abdomen that allows respiration to occur?
[ "spiracles", "wings", "chloroplasts", "gills" ]
A
Respiration that occurs without lungs. Insects have a system of internal tubes and sacs that oxygen travels through to reach body tissues. Air is taken in through the spiracles , openings on the sides of the abdomen.
train
sciq
null
Salts of weak acids or bases can affect the acidity or what of their aqueous solution?
[ "atomicity", "basicity", "compound", "ductility" ]
B
Salts of weak acids or bases can affect the acidity or basicity of their aqueous solutions.
train
sciq
null
Flowers, double fertilization, and fruits are unique features of what life cycle?
[ "dinoflagellate", "protozoa", "angiosperm", "early lifehood" ]
C
38.1 Flowers, double fertilization, and fruits are unique features of the angiosperm life cycle.
train
sciq
null
What is most often the cause of encephalitis?
[ "parasites", "viruses", "calcium buildup", "bacterial infections" ]
B
Encephalitis is a brain infection most often caused by viruses. The immune system tries to fight off a brain infection, just as it tries to fight off other infections. But sometimes this can do more harm than good. The immune system’s response may cause swelling in the brain. With no room to expand, the brain pushes ag...
train
sciq
null
Why do microwaves have a higher energy than radio waves?
[ "higher decibel", "lower frequency", "higher resonance", "higher frequency" ]
D
Find the microwave in the Figure above . A microwave is an electromagnetic wave with a relatively long wavelength and low frequency. Microwaves are often classified as radio waves, but they have higher frequencies than other radio waves. With higher frequencies, they also have more energy. That’s why microwaves are use...
train
sciq
null
What is cytology.
[ "the study of atomic structure", "the study of cell structure", "the study of plants", "the study of cancers" ]
B
train
sciq
null
When solids change to gasses, they generally pass through what other state?
[ "frozen", "liquid", "chemical", "carbon" ]
B
Solids that change to gases generally first pass through the liquid state. However, sometimes solids change directly to gases and skip the liquid state. The reverse can also occur. Sometimes gases change directly to solids.
train
sciq
null
What is the structure which hangs from a newly hatched salmon larva?
[ "liquid sac", "air sac", "yolk sac", "stomach sac" ]
C
Salmon Larva. This newly hatched salmon larva doesn’t look very fish-like. The structure hanging from the larva is the yolk sac.
train
sciq
null
What is made up of the pinna, ear canal, and eardrum?
[ "the nervous system", "the outer ear", "the epidermis", "the inner ear" ]
B
The outer ear includes the pinna, ear canal, and eardrum. These structures gather sound waves, funnel them into the ear, and pass the vibrations to the middle ear.
train
sciq
null
What type of solvents is glucose insoluble in?
[ "acidic", "alkaline", "polar", "nonpolar" ]
D
The same principles govern the solubilities of molecular solids in liquids. For example, elemental sulfur is a solid consisting of cyclic S8 molecules that have no dipole moment. Because the S8 rings in solid sulfur are held to other rings by London dispersion forces, elemental sulfur is insoluble in water. It is, howe...
train
sciq
null
What organ is divided into the duodenum, the jejunum, and the ileum?
[ "kidney", "lung", "small intestine", "large intestine" ]
C
Most chemical digestion and nearly all absorption of nutrients take place in the small intestine. This organ consists of three parts: duodenum, jejunum, and ileum.
train
sciq
null
Ectotherms undergo a variety of changes at the cellular level to acclimatize to shifts in what?
[ "oxygen", "precipitation", "temperature", "air pressure" ]
C
train
sciq
null
A comet striking the earth may have caused mass extinction, this would have decreased sunlight, which would have effected what plant process reducing food?
[ "glycolysis", "photosynthesis", "decomposition", "fertilization" ]
B
At the end of the Cretaceous Period, or 65 million years ago, all dinosaurs (except those which led to birds) went extinct. Some scientists believe a possible cause is a collision between the Earth and a comet or asteroid. The collision could have caused tidal waves, changed the climate, and reduced sunlight by 10-20%....
train
sciq
null
Normal body temperature is ideal for most of what type of reactions?
[ "gas", "plasma", "biochemical", "theoretical" ]
C
Biochemical reactions are optimal at physiological temperatures. For example, most biochemical reactions work best at the normal body temperature of 98.6˚F. Many enzymes lose function at lower and higher temperatures. At higher temperatures, an enzyme’s shape deteriorates. Only when the temperature comes back to normal...
train
sciq
null
What separates and strongly unites bodies of adjacent vertebrae?
[ "intervertebral disc", "collagen fibers", "interstitial fluid", "synovial fluid" ]
A
General Structure of a Vertebra Within the different regions of the vertebral column, vertebrae vary in size and shape, but they all follow a similar structural pattern. A typical vertebra will consist of a body, a vertebral arch, and seven processes (Figure 7.23). The body is the anterior portion of each vertebra and ...
train
sciq
null
About 20 percent of carbon dioxide is bound by hemoglobin and is transported where?
[ "bones", "lungs", "brain tissues", "intestines" ]
B
Carbaminohemoglobin About 20 percent of carbon dioxide is bound by hemoglobin and is transported to the lungs. Carbon dioxide does not bind to iron as oxygen does; instead, carbon dioxide binds amino acid moieties on the globin portions of hemoglobin to form carbaminohemoglobin, which forms when hemoglobin and carbon d...
train
sciq
null
Which outermost secondary xylem layers transport water?
[ "the farthest", "the oldest", "the youngest", "the narrowest" ]
C
train
sciq
null
What did volcanic gases help to form on earth?
[ "atmosphere", "water", "plants", "rocks" ]
A
When Earth first formed, it was a fiery hot, barren ball. It had no oceans or atmosphere. Rivers of melted rock flowed over its surface. Gradually, the planet cooled and formed a solid crust. Gases from volcanoes formed an atmosphere, although it contained only a trace of oxygen. As the planet continued to cool, clouds...
train
sciq
null
What is formed when the ceiling of an underground cave collapses?
[ "mountain", "groundwater", "sinkhole", "hill" ]
C
As erosion by groundwater continues, the ceiling of a cave may collapse. The rock and soil above it sink into the ground. This forms a sinkhole on the surface. You can see an example of a sinkhole in Figure below . Some sinkholes are big enough to swallow vehicles and buildings.
train
sciq
null
What type of muscle makes up most of the heart?
[ "respiratory muscle", "chest muscles", "heart muscle", "cardiac muscle" ]
D
The heart is a muscular organ in the chest that consists mainly of cardiac muscle. It pumps blood through blood vessels by repeated, rhythmic contractions. Blood flows through four chambers of the heart when it beats. Heartbeat is controlled by electrical signals from special cells within the heart called the pacemaker...
train
sciq
null
What measures the amount of water in the air?
[ "cloud cover", "humidity", "fire index", "temperature" ]
B
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).
train
sciq
null
Most terrestrial vertebrates have what type of lungs?
[ "internal", "external", "extra", "mechanical" ]
A
train
sciq
null
What process joins two haploid gametes into a diploid zygote?
[ "fertilization", "fusion", "embryo", "migration" ]
A
Fertilization joins two haploid gametes into a diploid zygote.
train
sciq
null
Planets are held by the force of gravity in elliptical orbits around what?
[ "jupitor", "sun", "mars", "earth" ]
B
Planets are held by the force of gravity in elliptical orbits around the Sun.
train
sciq
null
What is the fastest land animal?
[ "cheetah", "rhino", "greyhound", "ostrich" ]
A
Mammals are noted for the many ways they can move. Some mammals are well known for their speed. The fastest land animal is a mammal, the cheetah. It can race at speeds of up to 112 kilometers (70 miles) per hour.
train
sciq
null
What is the process by which the remains of living things become fossils?
[ "sublimation", "decomposition", "petrification", "fossilization" ]
D
The process by which remains or traces of living things become fossils is called fossilization . Most fossils are preserved in sedimentary rocks.
train
sciq
null
Meters, such as those in analog fuel gauges on a car, are a common application of magnetic torque on a current-carrying what?
[ "loop", "circuit", "dial", "arc" ]
A
Meters, such as those in analog fuel gauges on a car, are another common application of magnetic torque on a current-carrying loop. Figure 22.37 shows that a meter is very similar in construction to a motor. The meter in the figure has its magnets shaped to limit the effect of θ by making B perpendicular to the loop ov...
train
sciq
null
What causes reduction of elasticity in all organs?
[ "age", "radiation", "low vitamin D", "weight gain" ]
A
Unlike bones and tendons, which need to be strong as well as elastic, the arteries and lungs need to be very stretchable. The elastic properties of the arteries are essential for blood flow. The pressure in the arteries increases and arterial walls stretch when the blood is pumped out of the heart. When the aortic valv...
train
sciq
null
How many protons and electrons each do carbon atoms have?
[ "five", "nine", "six", "two" ]
C
Consider carbon as an example. Carbon atoms have six protons. They also have six electrons. All carbon atoms are the same whether they are found in a lump of coal or a teaspoon of table sugar ( Figure below ). On the other hand, carbon atoms are different from the atoms of hydrogen, which are also found in coal and sug...
train
sciq
null
What thickens the cortex around the inner edge of a cell?
[ "vacuoles", "mitochondria", "microfilaments", "plasma membrane" ]
C
Figure 4.22 Microfilaments thicken the cortex around the inner edge of a cell; like rubber bands, they resist tension. Microtubules are found in the interior of the cell where they maintain cell shape by resisting compressive forces. Intermediate filaments are found throughout the cell and hold organelles in place.
train
sciq
null
What value of dissolved substances is higher than that of their corresponding precipitate?
[ "entropy", "negentropy", "binary", "ordiny" ]
A
Dissolved substances have a higher entropy value than their corresponding precipitate.
train
sciq
null
Is an acid lower or higher than 7 on the ph scale?
[ "twice as much as 7", "higher than 7", "lower than 7", "exactly 7" ]
C
A: The weakest acid on the scale is milk, which has a pH value between 6.5 and 6.8. The strongest base on the scale is liquid drain cleaner, which has a pH of 14.
train
sciq
null
Although what biochemicals circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors?
[ "organs", "hormones", "Cells", "enzymes" ]
B
How Hormones Work Hormones cause changes in target cells by binding to specific cell-surface or intracellular hormone receptors, molecules embedded in the cell membrane or floating in the cytoplasm with a binding site that matches a binding site on the hormone molecule. In this way, even though hormones circulate throu...
train
sciq
null
The right atrium receives all of the systemic venous return. most of the blood flows into either the superior vena cava or this?
[ "exterior vena cava", "inferior vena cava", "identical vena cava", "resulted vena cava" ]
B
The right atrium receives all of the systemic venous return. Most of the blood flows into either the superior vena cava or inferior vena cava. If you draw an imaginary line at the level of the diaphragm, systemic venous circulation from above that line will generally flow into the superior vena cava; this includes bloo...
train
sciq
null
Tissue is made up of layers of tightly packed cells that line the surfaces of the body, such as skin.
[ "epithelial tissue", "weak tissue", "neural tissue", "resultant tissue" ]
A
Epithelial tissue is made up of layers of tightly packed cells that line the surfaces of the body. Examples of epithelial tissue include the skin, the lining of the mouth and nose, and the lining of the digestive system.
train
sciq
null
Most lipid hormones are derived from what?
[ "fat", "cholesterol", "tissue", "protein" ]
B
Lipid-Derived Hormones (or Lipid-soluble Hormones) Most lipid hormones are derived from cholesterol and thus are structurally similar to it, as illustrated in Figure 37.2. The primary class of lipid hormones in humans is the steroid hormones. Chemically, these hormones are usually ketones or alcohols; their chemical na...
train
sciq
null
A fact or question is only considered science if it has what property?
[ "it is testable", "it is mineral", "it is believable", "it is interesting" ]
A
Note the word science in that last sentence. Earth Science is a science, or maybe it’s made up of a lot of sciences. But what is science? Most people think of science as a bunch of knowledge. And it is. But science is also a way of knowing things. It’s different from other ways of knowing because it is based on a metho...
train
sciq
null
Which branch of science is the study of energy, matter, and their interactions?
[ "physics", "geology", "meteorology", "biology" ]
A
Physics is the study of energy, matter, and their interactions. It is concerned with matter and energy at all levels—from the most fundamental particles of matter to the entire universe.
train
sciq
null
What is the smallest unit capable of life known as?
[ "a cell", "insect", "organism", "living thing" ]
A
It could easily be said that a cell is the fundamental unit of life, the smallest unit capable of life or the structural and functional unit necessary for life. But whatever it is, a cell is necessary for life. And as shown above, a cell may be filled with all sorts of structures, each with its own specific function. T...
train
sciq
null
Making associations between experiences is often a part of what activity?
[ "eating", "sleeping", "dying", "learning" ]
D
train
sciq
null
The spectrum is made up of discrete lines representing transitions of the hydrogen electron between specific energy levels within what?
[ "the molecule", "an element", "the atom", "a rainbow" ]
C
The emission spectrum of hydrogen is discontinuous. The spectrum is made up of discrete lines representing transitions of the hydrogen electron between specific energy levels within the atom.
train
sciq
null
In the field of biodiversity, "richness" and "abundance" are used to describe different what?
[ "water sources", "species", "nutrients", "densities" ]
B
Biodiversity, Species Richness, and Relative Species Abundance Biodiversity describes a community’s biological complexity: it is measured by the number of different species (species richness) in a particular area and their relative abundance (species evenness). The area in question could be a habitat, a biome, or the e...
train
sciq
null
Nitrogen is an important macronutrient because it is part of nucleic acids and proteins. atmospheric nitrogen, which is the diatomic molecule n2, or dinitrogen, is the largest pool of nitrogen in these?
[ "terrestrial ecosystems", "aquatic ecosytems", "gas planets", "desert biomes" ]
A
Nitrogen Fixation: Root and Bacteria Interactions Nitrogen is an important macronutrient because it is part of nucleic acids and proteins. Atmospheric nitrogen, which is the diatomic molecule N2, or dinitrogen, is the largest pool of nitrogen in terrestrial ecosystems. However, plants cannot take advantage of this nitr...
train
sciq
null
What is the term for rotation of a bone toward the midline of the body?
[ "interior rotation", "medial rotation", "visual rotation", "lateral rotation" ]
B
Rotational Movement Rotational movement is the movement of a bone as it rotates around its longitudinal axis. Rotation can be toward the midline of the body, which is referred to as medial rotation, or away from the midline of the body, which is referred to as lateral rotation. Movement of the head from side to side is...
train
sciq
null
What cause rabies, measles, diarrheal diseases, hepatitis, polio, and cold sores?
[ "viruses", "bacteria", "parasites", "contaminants" ]
A
Viruses cause many human diseases. In addition to the diseases mentioned above, viruses cause rabies, measles, diarrheal diseases, hepatitis, polio, and cold sores (see Figure below ). Viral diseases range from mild to fatal. One way viruses cause disease is by causing host cells to burst open and die. Viruses may also...
train
sciq
null
What are the two methods in which mutations arise in dna?
[ "accelerated or spontaneous", "accelerated or random", "produced or spontaneous", "induced or spontaneous" ]
D
Errors during DNA replication are not the only reason why mutations arise in DNA. Mutations, variations in the nucleotide sequence of a genome, can also occur because of damage to DNA. Such mutations may be of two types: induced or spontaneous. Induced mutations are those that result from an exposure to chemicals, UV r...
train
sciq
null
Water follows where sodium ions lead, due to what process?
[ "absorption", "electrolysis", "hydration", "osmosis" ]
D
Blood Pressure Regulation Due to osmosis, water follows where Na+ leads. Much of the water the kidneys recover from the forming urine follows the reabsorption of Na+. ADH stimulation of aquaporin channels allows for regulation of water recovery in the collecting ducts. Normally, all of the glucose is recovered, but los...
train
sciq
null
What group of simple organisms recycles nutrients and has been on earth since long before multicellular life appeared?
[ "protists", "prokaryotes", "bacteria", "eukaryotes" ]
B
22.1 | Prokaryotic Diversity By the end of this section, you will be able to: • Describe the evolutionary history of prokaryotes • Discuss the distinguishing features of extremophiles • Explain why it is difficult to culture prokaryotes Prokaryotes are ubiquitous. They cover every imaginable surface where there is suff...
train
sciq
null
What is the term for dry climate regions at higher altitudes that have short grasses and low bushes?
[ "deserts", "prairie", "fringes", "steppes" ]
D
Other dry climates get a little more precipitation. They are called steppes . These regions have short grasses and low bushes (see Figure below ). Steppes occur at higher latitudes than deserts. They are dry because they are in continental interiors or rain shadows.
train
sciq
null