Reading for comprehension Flashcards
A) Both Vera and Marcia could be correct. Based on the cladogram, it is equally possible that “unknown trait A” is presence of a backbone or warm-blooded.
B) Marcia is correct, because all the animals following the appearance of “unknown trait A” are warm-blooded.
C) Vera is correct, because all the animals following the appearance of “unknown trait A” have a backbone.
D) Neither Vera nor Marcia are correct. The unknown trait is meat-eating.
What must happen for allopatric speciation to occur?
A) A group within a species must die so that others with traits better suited to the environment can survive.
B) A group within a species must integrate itself into a different group of the same species.
C) A group within a species must move to an isolated area so it can adapt independently from the rest of the species.
D) A group within a species must travel across the world and integrate members into all the other groups of the same species.
The correct answer is C.
Explanation:
The passage states, “During allopatric speciation, a population splits into two geographically isolated populations.”
For allopatric speciation to occur, the populations have to be separated so that they become two distinct species. Eventually, they will evolve to the point where they are no longer able to reproduce with the other population.
Which term best describes the Moon being exactly lined up with the Sun, as viewed from Earth?
Phases of the Moon
We only see the Moon because sunlight reflects back to us from its surface. During the course of a month, the Moon circles once around the Earth. If we could magically look down on our solar system, we would see that the half of the Moon facing the Sun is always lit. But the lit side does not always face the Earth! As the Moon circles the Earth, the amount of the lit side we see changes. These changes are known as the phases of the Moon and it repeats in a certain way over and over.
At new moon, the Moon is lined up between the Earth and the Sun. We see the side of the Moon that is not being lit by the Sun (in other words, we see no Moon at all, because the brightness of the Sun outshines the dim Moon!) When the Moon is exactly lined up with the Sun (as viewed from Earth), we experience an eclipse.
As the Moon moves eastward away from the Sun in the sky, we see a bit more of the sunlit side of the Moon each night. A few days after new moon, we see a thin crescent in the western evening sky. The crescent Moon waxes or appears to grow fatter, each night. When half of the Moon’s disc is illuminated, we call it the first quarter moon. This name comes from the fact that the Moon is now one-quarter of the way through the lunar month. From Earth, we are now looking at the sunlit side of the Moon from off to the side.
The Moon continues to wax. Once more than half of the disc is illuminated, it has a shape we call gibbous. The gibbous moon appears to grow fatter each night until we see the full sunlit face of the Moon. We call this phase the full moon. It rises almost exactly as the Sun sets and sets just as the Sun rises the next day. The Moon has now completed one half of the lunar month.
During the second half of the lunar month, the Moon grows thinner each night. We call this waning. Its shape is still gibbous at this point but grows a little thinner each night. As it reaches the three-quarter point in its month, the Moon once again shows us one side of its disc illuminated and the other side in darkness. However, the side that we saw dark at the first quarter phase is now the lit side. As it completes its journey and approaches new moon again, the Moon is a waning crescent.
A) first quarter moon
B) new moon
C) waning crescent
D) eclipse
The correct answer is D.
Explanation:
The passage describes the cause of an eclipse.
“At new moon, the Moon is lined up between the Earth and the Sun. We see the side of the Moon that is not being lit by the Sun (in other words, we see no Moon at all, because the brightness of the Sun outshines the dim Moon!) When the Moon is exactly lined up with the Sun (as viewed from Earth), we experience an eclipse.”
Notice that a new moon occurs when the Moon lines up between Earth and the Sun, but an eclipse only occurs when the Moon and Sun are lined up exactly when viewed from Earth. During a first and third quarter moon, the Earth sees half of the Moon’s surface lit up. During a waning crescent, only a small section of the Moon’s surface appears to be lit up.
According to the passage, how does the process of plate tectonics cause volcanoes along the Ring of Fire?
Ring of Fire
The Ring of Fire is an area that surrounds much of the Pacific Ocean, where lithospheric plates are rubbing against and over one another in a process known as plate tectonics. Places where lithospheric plates are moving toward one another (called convergent plate boundaries), can create volcanoes when material from the oceanic plate is subducted under the continental plate, melts due to the increased temperature and pressure, and rises to the surface in the form of magma. Convergent plate boundaries can also create oceanic trenches, which are long depressions in the sea floor. These trenches make up some of the deepest areas of the ocean, with the Marianas Trench being the deepest of all.
A) A continental plate is subducted beneath an oceanic plate.
B) An oceanic plate is subducted beneath a continental plate.
C) A continental plate is subducted beneath a second continental plate.
D) Two oceanic plates move farther apart.
The correct answer is B.
Explanation:
The answer is found in the following excerpt, “Places where lithospheric plates are moving toward one another (called convergent plate boundaries), can create volcanoes when material from the oceanic plate is subducted under the continental plate, melts due to the increased temperature and pressure, and rises to the surface in the form of magma.”
Based on the passage, which of the following is the most likely explanation for why mercury exposure from seafood can pose such a serious threat to humans?
Environmental Changes, Food Chains, and Food Webs: Mercury’s Impact
Mercury is a highly toxic element that is found both naturally and as an introduced contaminant in the environment. Although its potential for toxicity in highly contaminated areas such as Minamata Bay, Japan, in the 1950’s and 1960’s, is well documented, research has shown that mercury can be a threat to the health of people and wildlife in many environments that are not obviously polluted. The risk is determined by the likelihood of exposure, the form of mercury present (some forms are more toxic than others), and the geochemical and ecological factors that influence how mercury moves and changes form in the environment.
The toxic effects of mercury depend on its chemical form and the route of exposure. Methylmercury [CH3HgCH3Hg] is the most toxic form. It affects the immune system, alters genetic and enzyme systems, and damages the nervous system, including coordination and the senses of touch, taste, and sight. Methylmercury is particularly damaging to developing embryos, which are five to ten times more sensitive than adults. Exposure to methylmercury is usually by ingestion, and it is absorbed more readily and excreted more slowly than other forms of mercury.
People are exposed to methylmercury almost entirely by eating contaminated fish and wildlife that are at the top of aquatic food chains. The National Research Council, in its 2000 report on the toxicological effects of methylmercury, pointed out that the population at highest risk is the offspring of women who consume large amounts of fish and seafood. The report went on to estimate that more than 60,00060,000 children are born each year at risk for adverse neurodevelopmental effects due to in utero exposure to methylmercury. In its 1997 Mercury Study Report to Congress, the US Environmental Protection Agency concluded that mercury also may pose a risk to some adults and wildlife populations that consume large amounts of fish that is contaminated by mercury.
In several areas of the United States, concentrations of mercury in fish and wildlife are high enough to be a risk to wildlife. It is difficult to prove cause and effect in field studies, however, because other factors that may contribute to the biological effect under study (for example, reproductive success) are often impossible to control. Scientists have discovered toxic effects in the field at concentrations of mercury that are toxic in the lab, and controlled lab studies have found toxic effects at concentrations that are common in certain environments. In studies in Wisconsin, reductions in loon chick production has been found in lakes where mercury concentrations in eggs exceed concentrations that are toxic in laboratory studies. At dietary mercury concentrations that are typical of parts of the Everglades, the behavior of juvenile great egrets can be affected. Studies with mallards, great egrets, and other aquatic birds have shown that protective enzymes are less effective following exposure to mercury. Analyses of such biochemical indicators indicate that mercury is adversely affecting diving ducks from the San Francisco Bay, herons and egrets from the Carson River, Nevada, and heron embryos from colonies along the Mississippi River. Finally, other contaminants also affect the toxicity of mercury. Methylmercury can be more harmful to bird embryos when selenium, another potentially toxic element, is present in the diet.
The exact mechanisms by which mercury enters the food chain remain largely unknown and may vary among ecosystems. Certain bacteria play an important early role. Bacteria that process sulfate (SO4SO4=) in the environment take up mercury in its inorganic form and convert it to methylmercury through metabolic processes. The conversion of inorganic mercury to methylmercury is important because its toxicity is greater and because organisms require considerably longer to eliminate methylmercury. These methylmercury-containing bacteria may be consumed by the next higher level in the food chain, or the bacteria may excrete the methylmercury to the water where it can quickly adsorb to plankton, which are also consumed by the next level in the food chain. Because animals accumulate methylmercury faster than they eliminate it, animals consume higher concentrations of mercury at each successive level of the food chain. Small environmental concentrations of methylmercury can thus readily accumulate to potentially harmful concentrations in fish, fish-eating wildlife and people. Even at very low atmospheric deposition rates in locations remote from point sources, mercury biomagnification can result in toxic effects in consumers at the top of these aquatic food chains.
Source: https://www2.usgs.gov/themes/factsheet/146-00/
A) Because mercury takes a long time to be eliminated from the body, it accumulates at increasingly higher concentrations at higher levels in the food chain; some of the seafood that humans consume contains dangerously high concentrations of mercury.
B) Most seafood contains a specific kind of bacteria that converts mercury into the form that is most toxic for humans.
C) Aquatic organisms are the only organisms that store mercury; therefore, seafood is the only food source that could potentially expose humans to its toxic effects.
D) None of these explanations is correct; seafood poses no greater threat of mercury exposure than any other plant or animal.
The correct answer is A.
Explanation:
The passage states that “People are exposed to methylmercury almost entirely by eating contaminated fish and wildlife that are at the top of aquatic food chains.” One reason for this is that mercury can enter these food chains more easily than others through a variety of mechanisms. Why this matters so much in the case of mercury, however, is that “animals accumulate methylmercury faster than they eliminate it,” which in turn means that “animals consume higher concentrations of mercury at each successive level of the food chain. Small environmental concentrations of methylmercury can thus readily accumulate to potentially harmful concentrations in fish, fish-eating wildlife and people.” This process is called biomagnification and explains why seemingly small amounts of mercury pollution can have serious consequences on ecosystems.
Which of the following examples best represents speciation?
Speciation
Speciation is the evolutionary process by which biological populations evolve to become distinct species. The biologist Orator F. Cook coined the term speciation in 1906, but Charles Darwin was the first to describe the role of speciation in his 1859 book The Origin of Species.
There are four geographic modes of speciation in nature, based on the extent to which speciating populations are isolated from one another: allopatric, peripatric, parapatric, and sympatric. Allopatric and peripatric are the two most observed modes of speciation.
During allopatric speciation, a population splits into two geographically isolated populations. The isolated populations then undergo genotypic or phenotypic divergence as they become subjected to dissimilar selective pressures and as different mutations arise. When the populations come back into contact, they have evolved such that they are reproductively isolated and are no longer capable of exchanging genes.
The Galápagos Islands are particularly famous for their confirmation of allopatric speciation. During Charles Darwin’s five weeks on the Galápagos Islands, he noticed that finches differed from one island to another. When he returned to England, his speculation on evolution deepened after experts informed him that these were separate species, not just varieties. Darwin’s finches are now one of the most well-known examples of adaptive evolution and allopatric speciation discussed in biology today.
In peripatric speciation, a sub-form of allopatric speciation, new species are formed in isolated, smaller peripheral populations that are prevented from exchanging genes with the main population. Since this is a sub-form of allopatric speciation, it is often difficult to determine if peripatric speciation occurs. The biggest indicator of peripatric speciation is that the isolated species will be a much smaller group than the non-isolated population.
Source: https://en.wikipedia.org/wiki/Peripatric_speciation
A) Dogs across the world have similar characteristics.
B) Galapagos finches on different islands developed different types of beaks.
C) Pigeons around the United States were captured and found to have similar beaks.
D) Wooly mammoth remains were found on four different continents.
The correct answer is B.
Explanation:
The passage states, “Darwin’s finches are now one of the most well-known examples of adaptive evolution and allopatric speciation discussed in biology today.”
The Galapagos finches are a model example of speciation.
Based on the passage, what is the primary cause of ocean acidification?
Ocean Acidification
For more than 200200 years, . . . the concentration of carbon dioxide (CO2CO2) in the atmosphere has increased due to the burning of fossil fuels and land use change. The ocean absorbs about 3030 percent of the CO2CO2 that is released in the atmosphere, and as levels of atmospheric CO2CO2 increase, so do the levels in the ocean.
When CO2CO2 is absorbed by seawater, a series of chemical reactions occur resulting in the increased concentration of hydrogen ions. This increase causes the seawater to become more acidic and causes carbonate ions to be relatively less abundant. Carbonate ions are an important building block of structures such as sea shells and coral skeletons. Decreases in carbonate ions can make building and maintaining shells and other calcium carbonate structures difficult for calcifying organisms such as oysters, clams, sea urchins, shallow water corals, deep sea corals, and calcareous plankton.
These changes in ocean chemistry can affect the behavior of non-calcifying organisms as well. Certain fish’s ability to detect predators is decreased in more acidic waters. When these organisms are at risk, the entire food web may also be at risk. Ocean acidification is affecting the entire world’s oceans, including coastal estuaries and waterways. Many economies are dependent on fish and shellfish and people worldwide rely on food from the ocean as their primary source of protein.
Source: https://oceanservice.noaa.gov/facts/acidification.html
A) human activity
B) natural cycles
C) solar flares
D) None of the above
The correct answer is A.
Explanation:
The passage begins by stating that “[f]or more than 200 years, . . . the concentration of carbon dioxide (CO2CO2) in the atmosphere has increased due to the burning of fossil fuels and land use change. The ocean absorbs about 30 percent of the CO2CO2 that is released in the atmosphere . . . When CO2 is absorbed by seawater, a series of chemical reactions occur resulting in the increased concentration of hydrogen ions. This increase causes the seawater to become more acidic.” The burning of fossil fuels and land use changes are both forms of human activity. Throughout the passage, no other sources are mentioned for ocean acidification.
Martha, Grace, and Neil are lab partners for a limiting reactants chemistry lab.
They each react 44 molecules of iron (Fe)(Fe) with 66 molecules of chlorine (Cl2)(Cl2) using the balanced chemical equation:
2Fe+3Cl2→2FeCl32Fe+3Cl2→2FeCl3
Martha finds that iron (Fe)(Fe) is the limiting reactant. Grace finds that chlorine (Cl2)(Cl2) is the limiting reactant. Neil finds that both reactants are used up equally, thus there is not a limiting reactant.
Who is correct? Why?
Limiting Reactants
In the majority of chemical reactions, the reaction will continue until one reactant runs out. Once one reactant is used up, the reaction will stop. This limiting reactant controls how much product can be produced because it limits how long the reaction can continue.
In a balanced chemical equation, the coefficients represent the relative number of molecules of reactants and products that are respectively used and produced during the course of the reaction. The ratios can be used to determine which reactant will be used up first.
A) Grace is correct. Chlorine molecules are used at a faster rate than iron molecules in this reaction.
B) Grace and Martha are both correct. It depends on if they added iron to the chlorine or the chlorine to the iron.
C) Martha is correct. There are only four iron molecules, so they will be used at a faster rate than chlorine in this reaction.
D) Neil is correct. Four molecules of iron will completely react with six molecules of chlorine and there will be no iron or chlorine left over.
The correct answer is D.
Explanation:
The passage states that “the coefficients represent the relative number of molecules of reactants and products that are respectively used and produced during the course of the reaction.” Coefficients and coefficient proportions can be compared to determine which reactant is limiting in the equation.
2Fe+3Cl2→2FeCl32Fe+3Cl2→2FeCl3
The order that elements are added together does not impact limiting reactants.
Identify the coefficients of the reactants.Fe:2
Cl2:3
Create a ratio representing the number of molecules in the reactionFe:Cl2
2:3
For every 2 molecules of iron used in this reaction, 3 molecule of chlorine is used.
Calculate equivalent ratios.2:3
4 molecules of iron will react with 6 molecules of chlorine.4:6
In this experiment, 4 molecules of iron are reacting with 6 molecules of chlorine. These ratios align with ratio equivalents of the equation’s coefficients. Therefore, all iron and chlorine will be completely used in this reaction and there will not be a limiting reactant. Neil is correct.
Which of the following best describe what the major extinctions noted on the timeline indicate?
The Evolution of Life on Earth
A very selective history of life on Earth over the past 600 million years is provided in the figure below. The major groups of organisms that we are familiar with evolved between the late Proterozoic and the Cambrian (~600 Ma to ~520 Ma). Plants, which evolved in the oceans as green algae, came onto land during the Ordovician (~450 Ma). Insects, which evolved from marine arthropods, came onto land during the Devonian (400 Ma), and amphibians (i.e., vertebrates) came onto land about 50 million years later. By the late Carboniferous, trees had evolved from earlier plants, and reptiles had evolved from amphibians. By the mid-Triassic, dinosaurs and mammals had evolved from very different branches of the reptiles; birds evolved from dinosaurs during the Jurassic. Flowering plants evolved in the late Jurassic or early Cretaceous. The earliest primates evolved from other mammals in the early Paleogene, and the genus Homo evolved during the late Neogene (~2.8 Ma).
The Phanerozoic has seen five major extinctions, as indicated in the graph. The most significant of these was at the end of the Permian, which saw the extinction of over 80% of all species and over 90% of all marine species. Most well-known types of organisms were decimated by this event, but only a few became completely extinct, including trilobites. The second most significant extinction was at the Cretaceous-Paleogene boundary (K-Pg, a.k.a. the K-T extinction). At that time, about 75% of marine species disappeared. Again, a few well-known types of organisms disappeared altogether, including dinosaurs (but not birds) and the pterosaurs. Other types were badly decimated but survived, and then flourished in the Paleogene. The K-Pg extinction is thought to have been caused by the impact of a large extraterrestrial body (10 km to 15 km across), but it is generally agreed that the other four Phanerozoic extinctions had other causes, although their exact nature is not clearly understood.
Source: https://opentextbc.ca/geology/chapter/8-3-dating-rocks-using-fossils/
A All organisms before those extinctions were wiped out, and life on Earth began again after each extinction.
B No fossil evidence prior to these extinctions survives.
C The Earth did not form until 540 million years ago.
D Many, but not all, species of life on Earth were wiped out by these extinctions.
The correct answer is D.
Explanation:
If it were true that no fossil evidence prior to these extinctions survives, we could not have obtained the knowledge we now have about species that lived prior to written human history. The graph is a condensed version of the history of life on Earth and makes no mention of the Earth’s formation (about 4.5 billion years ago). Finally, if no species had survived any of the extinctions, it is unlikely we would have birds, trees, insects, or anything in the modern age that dates back to before these extinctions. The process of evolution is governed by chance, and almost certainly would not have replicated these organisms.
Based on the passage, what is the pH of pure water?
pH Scale
One way that scientists classify chemicals is by their pH values. The pH scale ranges from 0 to 14. It is based on the pH value of pure water, which is located in the middle of the scale and is considered to be neutral.
If a substance has a pH value below that of water, it is considered acidic. If a substance has a pH value above that of water, it is considered basic. The further a pH value is from neutral, the more acidic or basic it is.
A 5.0
B 6.0
C 7.0
D 8.0
The correct answer is C.
Explanation:
The passage states “The pH scale ranges from 0 to 14. It is based on the pH value of pure water, which is located in the middle of the scale and is considered to be neutral.”
7.0 is the middle of the scale and is the pH of water.
Carter woke up at 10:00 am Saturday morning. He went to the kitchen, ate breakfast, took out the garbage, and ran a mile around his neighborhood. He then went to the store and bought groceries for the coming week. At 4:00 pm, he took a nap.
Carter’s wife, Nancy, left at 7:00 am when Carter was still sleeping and got back at 4:15 pm, where she saw Carter still in bed.
What can Nancy conclude?
Speed and Velocity
Speed and velocity are often used interchangeably in everyday use. Even though their equations are very similar, there is a distinct difference when using these terms in a physics context. Speed is based on distance, whereas velocity is based on displacement. Distance is how much ground an object has covered during its motion. Displacement is how far an object is away from its starting position. The two formulas are given in the following table.
A Nancy can conclude that Carter did not do anything.
B Nancy can conclude that Carter did not travel any distance.
C Nancy can conclude that Carter’s displacement is one mile.
D Nancy can conclude that Carter’s displacement is zero.
The correct answer is D.
Explanation:
Nancy can conclude that Carter’s displacement is zero.
The passage states that: “Distance is how much ground an object has covered during its motion. Displacement is how far an object is away from its starting position.” Distance and displacement are two different quantities.
Carter ran a mile, went to the grocery store, and walked around the house. All of these quantities represent distance traveled. However, Carter’s displacement is zero. He is in the same location at 4:15 pm as he was at 10:00 am.
Choose the term that best completes the following sentence:
_____ transport oxygenated blood from the heart to the body tissues.
Blood Vessels
Blood vessels are the channels or conduits through which blood is distributed to body tissues. The vessels make up two closed systems of tubes that begin and end at the heart. One system, the pulmonary vessels, transports blood from the right ventricle to the lungs and back to the left atrium. The other system, the systemic vessels, carries blood from the left ventricle to the tissues in all parts of the body and then returns the blood to the right atrium. Based on their structure and function, blood vessels are classified as either arteries, capillaries, or veins.
Arteries carry blood away from the heart. Pulmonary arteries transport blood that has a low oxygen content from the right ventricle to the lungs. Systemic arteries transport oxygenated blood from the left ventricle to the body tissues. Blood is pumped from the ventricles into large elastic arteries that branch repeatedly into smaller and smaller arteries until the branching results in microscopic arteries called arterioles. The arterioles play a key role in regulating blood flow into the tissue capillaries.
Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins). The primary function of capillaries is the exchange of materials between the blood and tissue cells.
Veins carry blood toward the heart. After blood passes through the capillaries, it enters the smallest veins, called venules. From the venules, it flows into progressively larger and larger veins until it reaches the heart. In the pulmonary circuit, the pulmonary veins transport blood from the lungs to the left atrium of the heart. This blood has a high oxygen content because it has just been oxygenated in the lungs. Systemic veins transport blood from the body tissue to the right atrium of the heart. This blood has a reduced oxygen content because the oxygen has been used for metabolic activities in the tissue cells.
Source: https://training.seer.cancer.gov/anatomy/cardiovascular/blood/classification.html
A Pulmonary arteries
B Pulmonary veins
C Systemic arteries
D Systemic veins
The correct answer is C.
Explanation:
Systemic arteries transport oxygenated blood from the heart to the body tissues.
This process is described in the second paragraph of the passage. “Systemic arteries transport oxygenated blood from the left ventricle to the body tissues. Blood is pumped from the ventricles into large elastic arteries that branch repeatedly into smaller and smaller arteries until the branching results in microscopic arteries called arterioles.”
As used in the passage, which of the following best describes the meaning of pathogenic?
Foodborne Illnesses Caused by Bacteria
Foodborne illness is often caused by eating food contaminated with bacteria. E. coli, Salmonella, and Listeria are three types of bacteria that commonly cause foodborne illness. While the American food supply is among the safest in the world, the Federal government estimates that there are about 4848 million cases of foodborne illness each year. This estimate is equal to about 11 in 66 Americans becoming sick from consuming food contaminated with bacteria. This results in an estimated 128,000128,000 hospitalizations and 3,0003,000 deaths each year.
Foodborne illness occurs when a person develops an infection after consuming contaminated food. There are several factors that contribute to the symptoms and severity of food poisoning. People with a weakened immune system, as well as the very old or very young are most vulnerable to foodborne illness.
Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and actually are an important part of a healthy human intestinal tract. However, some E. coli are pathogenic, causing diarrhea or more serious conditions, such as anemia or kidney failure. The types of E. coli that cause illness can be transmitted through contaminated water or food, or through contact with animals or people.
Salmonella can cause serious and sometimes fatal infections in young children, frail or elderly people, and others with weakened immune systems. Healthy people infected with Salmonella often experience fever, diarrhea, nausea, vomiting, and abdominal pain. In rare circumstances, infection with Salmonella can result in more severe illnesses if the bacteria enter the patient’s bloodstream.
Listeria is a harmful bacterium that can be found in refrigerated, ready-to-eat foods like meat, poultry, seafood, and dairy. It may also be found in produce harvested from soil that is contaminated with Listeria. Listeria is unusual because it can grow at refrigerator temperatures. Most other foodborne bacteria do not grow well at such low temperatures. But since Listeria can survive at low temperatures, even foods that are properly refrigerated may contain harmful bacteria. People who eat foods contaminated with Listeria may develop listeriosis, an illness which causes symptoms such as fever, headache and vomiting. For most people, listeriosis is not a serious illness. However, pregnant women and their unborn children are very susceptible to a more serious form of the illness. Among pregnant women who develop listeriosis, 22%22% of their unborn children will not survive.
Source: https://www.fda.gov/Food/FoodborneIllnessContaminants/Bacteria/ucm20081848.htm
A causing illness
B contaminated with bacteria
C fatal
D harmless
The correct answer is A.
Explanation:
The parts of the passage that help to explain the meaning of the word are in bold. Although the previous sentence indicates that most E. coli are harmless, the sentence that contains the word pathogenic indicates that some E. coli are not harmless and can cause illness.
As stated in the passage, “Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and actually are an important part of a healthy human intestinal tract. However, some E. coli are pathogenic, causing diarrhea or more serious conditions, such as anemia or kidney failure. The types of E. coli that cause illness can be transmitted through contaminated water or food, or through contact with animals or people.”
Besides Jupiter, which of following other gas planets have ring systems?
Jupiter’s Rings
The planet Jupiter has a system of rings known as the rings of Jupiter or the Jovian ring system. It was the third ring system to be discovered in the Solar System, after those of Saturn and Uranus. It was first observed in 1979 by the Voyager 1 space probe and thoroughly investigated in the 1990s by the Galileo orbiter. It has also been observed by the Hubble Space Telescope and from Earth for the past 23 years. Ground-based observations of the rings require the largest available telescopes.
The Jovian ring system is faint and consists mainly of dust. It has four main components: a thick inner torus (circular system) of particles known as the “halo ring”; a relatively bright, exceptionally thin “main ring”; and two wide, thick and faint outer “gossamer rings”, named for the moons of whose material they are composed: Amalthea and Thebe.
The main and halo rings consist of dust ejected from the moons Metis, Adrastea, and other unobserved parent bodies as the result of high-velocity impacts. High-resolution images obtained in February and March 2007 by the New Horizons spacecraft revealed a rich fine structure in the main ring.
In visible and near-infrared light, the rings have a reddish color, except the halo ring, which is neutral or blue in color. The size of the dust in the rings varies, but the cross-sectional area is greatest for nonspherical particles of radius about 15 μm in all rings except the halo. The halo ring is probably dominated by submicrometre dust. The total mass of the ring system (including unresolved parent bodies) is poorly known but is probably in the range of 1011 to 1016 kg. The age of the ring system is not known, but it may have existed since the formation of Jupiter.
A ring could possibly exist in Himalia’s orbit. One possible explanation is that a small moon had crashed into Himalia and the force of the impact caused material to blast off Himalia.
Source: https://en.wikipedia.org/wiki/Rings_of_Jupiter
A Mercury and Venus
B Mars and Venus
C Neptune and Mars
D Saturn and Uranus
The correct answer is D.
Explanation:
Although Saturn is best known for its ring system, the giant planets—Jupiter, Saturn, Uranus, and Neptune—all have ring systems. A planetary ring system is a disc or ring of solid material such as dust that orbits a planet. According to the passage, “The planet Jupiter has a system of rings known as the rings of Jupiter or the Jovian ring system. It was the third ring system to be discovered in the Solar System, after those of Saturn and Uranus.” The best answer choice is D, as it lists Saturn and Uranus as mentioned in the passage.
Which of the following statements is used in the passage as examples of the synthesis of complex molecules from simpler molecules?
Anabolic and Catabolic Pathways
Anabolic pathways require an input of energy to synthesize complex molecules from simpler ones. Synthesizing sugar from carbon dioxide (CO2CO2) is one example. Other examples are the synthesis of large proteins from amino acid building blocks, and the synthesis of new DNA strands from nucleic acid building blocks. These biosynthetic processes are critical to the life of the cell, take place constantly, and demand energy provided by ATP (adenosine triphosphate) and other high-energy molecules like NADH (nicotinamide adenine dinucleotide) and NADPH (nicotinamide adenine dinucleotide phosphate).
ATP is an important molecule for cells to have in sufficient supply at all times. The breakdown of sugars illustrates how a single molecule of glucose can store enough energy to make a great deal of ATP, 36 to 38 molecules. This is a catabolic pathway. Catabolic pathways involve the degradation (or breakdown) of complex molecules into simpler ones. Molecular energy stored in the bonds of complex molecules is released in catabolic pathways and harvested in such a way that it can be used to produce ATP. Other energy-storing molecules, such as fats, are also broken down through similar catabolic reactions to release energy and make ATP.
It is important to know that the chemical reactions of metabolic pathways don’t take place spontaneously. Each reaction step is facilitated, or catalyzed, by a protein called an enzyme. Enzymes are important for catalyzing all types of biological reactions—those that require energy as well as those that release energy.
A new DNA strands from nucleic acid building blocks
B large proteins from amino acid building blocks
C sugar from CO2CO2
D All of the above
The correct answer is D.
Explanation:
All of the examples were used in the passage as anabolic pathway examples to demonstrate the synthesis of complex molecules from simpler ones.
“Anabolic pathways require an input of energy to synthesize complex molecules from simpler ones. Synthesizing sugar from carbon dioxide (CO2CO2) is one example. Other examples are the synthesis of large proteins from amino acid building blocks, and the synthesis of new DNA strands from nucleic acid building blocks.”
It is hotter than normal this summer in the town of Lakeside View. With a large lake to the west and mountains to the east, Arlene and Victor wonder how warmer temperatures will affect Lakeside View’s local climate.
Victor says that the warmer temperatures will increase the evaporation phase of the water cycle and cause the lake levels to be lower than in previous summers. Arlene says that the warmer temperatures will increase the precipitation phase of the water cycle and there will be more rain than in previous summers.
Who is correct? Why?
The water cycle has no starting point, but for this description, the ocean will be the beginning, since that is where most of Earth’s water exists. The sun, which drives the water cycle, heats water in the oceans. Most of the water evaporates as vapor into the air, where rising air currents take the vapor up into the atmosphere. In the atmosphere, cooler temperatures cause the water vapor to condense into clouds.
Air currents move clouds around the globe, and cloud particles collide, grow, and fall out of the sky as precipitation. Some precipitation falls as snow and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years. Snowpacks in warmer climates often thaw and melt when spring arrives, and the melted water flows overland as snowmelt. Most precipitation falls back into the oceans or onto land, where, due to gravity, the precipitation flows over the ground as surface runoff. A portion of runoff enters rivers in valleys in the landscape, with streamflow moving water towards the oceans.
Not all runoff flows into rivers, though. Much of it soaks into the ground as infiltration. Some of the water infiltrates into the ground and replenishes aquifers (saturated subsurface rock), which store huge amounts of freshwater for long periods of time. Some infiltration stays close to the land surface and can seep back into surface-water bodies (and the ocean) as groundwater discharge, and some groundwater finds openings in the land surface and emerges as freshwater springs. Yet more groundwater is absorbed by plant roots to end up as evapotranspiration from the leaves. Over time, though, all of this water keeps moving, some to reenter the ocean, where the water cycle begins all over again.
Source: https://water.usgs.gov/edu/watercyclesummary.html
Source: https://www.flickr.com/photos/atmospheric-infrared-sounder/8265046380/sizes/l
A Arlene is correct. Warmer temperatures will cause more precipitation in and around Lakeside View.
B Both Arlene and Victor are correct. Warmer temperatures, due to increased sunlight, will cause all aspects of the water cycle to increase.
C Neither Arlene nor Victor are correct. Warmer temperatures will not affect any aspect of the water cycle, so neither evaporation nor precipitation will increase.
D Victor is correct. Warmer temperatures will cause more evaporation of Lakeside View’s local lake.
The correct answer is B.
Explanation:
Both Arlene and Victor are correct. Warmer temperatures, due to increased sunlight, will cause all aspects of the water cycle to increase.
The passage states, “The sun, which drives the water cycle, heats water in the oceans. Most of the water evaporates as vapor into the air, where rising air currents take the vapor up into the atmosphere. In the atmosphere, cooler temperatures cause the water vapor to condense into clouds. Air currents move clouds around the globe, and cloud particles collide, grow, and fall out of the sky as precipitation.”
If temperatures are increasing, that means more sunlight is reaching the town of Lakeside View. Since the sun drives the water cycle, more sunlight will result in more evaporation. Evaporation is linked to precipitation, as evaporated water rises into the atmosphere, condenses into clouds, and falls back to Earth as precipitation. Both Arlene and Victor are correct.
Hector, Ophelia, and Yvonne are trying to make sense of the information displayed in the graph. Hector says that renewable energy is primarily used in the electric power sector. Ophelia says that petroleum is primarily used in the transportation sector. Yvonne says that coal is primarily used in the industrial sector.
Who is correct?
US Primary Energy Consumption by Source and Sector, 2016
This graphic shows US primary energy consumption in 2016.
Energy sources are listed on the left side of the graph and the sectors that use these energy sources are listed on the right side of the graph.
The lines and arrows connecting the two sides of the graphic break down how each source was used by each sector.
Source: https://www.eia.gov/EnergyExplained/index.cfm?page=us_energy_home
A Hector, Ophelia, and Yvonne are all correct.
B Hector and Ophelia are correct, but Yvonne is not correct.
C Hector and Yvonne are correct, but Ophelia is not correct.
D Ophelia and Yvonne are correct, but Hector is not correct.
The correct answer is B.
Explanation:
Hector and Ophelia are correct, but Yvonne is not correct.
As Hector stated, renewable energy is primarily used for electric power. 55% of all renewable energy in the United States is used by the electric power sector.
As Ophelia stated, petroleum is primarily used for transportation. 71% of all petroleum in the United States is used by the transportation sector.
Yvonne, however, was incorrect. A majority of coal (91%), is used by the electric power sector. Only 8% of coal is used by the industrial sector.
A scientist finds evidence that sea-like creatures live beneath the Earth’s crust. Another scientist says this cannot be true, since he has evidence that the Earth is completely solid beneath the crust.
Which of the following best describes the scientists’ findings?
The Mantle of the Earth
The Earth is made up of four distinct and unique layers: crust, mantle, outer core, and inner core. The crust of the Earth is the outermost layer and is made of solid rock. The mantle is beneath the crust and is made of very hot, dense rock. At 1800 miles thick, the mantle of the earth is the largest of Earth’s four layers. Because it is so thick, it has a large variation in temperature. The outermost portion of the mantle (the part that is closest to the crust) has a temperature of 500 to 900 degrees (Celsius). The interior of the mantle (the part closest to the outer core) reaches more than 4000 degrees (Celsius). At this temperature, some of the rocks melt, creating a semi-molten rock called magma.
Because part of the mantle is magma, it has semi-liquid properties. Continents, which float on the mantle, end up moving over time due to the movement of the mantle below. This phenomenon is referred to as plate tectonics.
Source: https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Earth_poster.svg/350px-Earth_poster.svg.png
A Both scientists could be correct. It is possible that sea-like creatures live inside of the Earth’s solid interior.
B Only the first scientist is correct. The Earth has solid and liquid components, so it is highly likely that sea-like creatures live inside the Earth’s liquid outer core.
C Only the second scientist is correct. The Earth is completely solid, which is how it is able to maintain its spherical shape.
D The first scientist could be correct, but it is highly unlikely. While the Earth’s outer core is liquid, it is extremely hot. It would be difficult for life to survive in such a hot environment.
The first scientist could be correct, but it is highly unlikely. While the Earth’s outer core is liquid, it is extremely hot. It would be difficult for life to survive in such a hot environment.
Sea creatures live in the ocean, where their environment is liquid. This implies that a sea-like creature living in the Earth would also need a liquid environment. This is possible, since the outer core of the Earth is liquid. However, it is highly unlikely that animals could survive at such high temperatures. It is also unlikely, as the liquid material in the center of the Earth is liquid rock, not liquid water.
A Both Henry and his brother are correct. Henry is describing speed, which uses distance; Henry’s brother is describing velocity, which uses displacement.
B Henry is correct. Each kilometer he walked took him ten minutes, so each minute he walked 0.1 kilometers.
C Henry’s brother is correct. Since Henry has a displacement of zero, he has no velocity.
D Neither Henry nor his brother are correct. Henry’s velocity is 0.1 km/minute
The correct answer is A.
Explanation:
Both Henry and his brother are correct. Henry is describing speed, which uses distance; Henry’s brother is describing velocity, which uses displacement. .
The passage states that: “Distance is how much ground an object has covered during its motion. Displacement is how far an object is away from its starting position.” Distance and displacement are two different quantities, which affect the calculations for speed and velocity.
After learning about the water cycle, Gertrude and Paola conduct some research. Gertrude measures the amount of precipitation that falls within a one-month period. Paola measures the water levels of the lake over the same one-month period. Gertrude finds that it has rained 13 inches in the last month, whereas Paola finds that the lake has only risen 2 inches in the last month.
Which of the following can be inferred from Gertrude and Paola’s data?
The water cycle has no starting point, but for this description, the ocean will be the beginning, since that is where most of Earth’s water exists. The sun, which drives the water cycle, heats water in the oceans. Most of the water evaporates as vapor into the air, where rising air currents take the vapor up into the atmosphere. In the atmosphere, cooler temperatures cause the water vapor to condense into clouds.
Air currents move clouds around the globe, and cloud particles collide, grow, and fall out of the sky as precipitation. Some precipitation falls as snow and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years. Snowpacks in warmer climates often thaw and melt when spring arrives, and the melted water flows overland as snowmelt. Most precipitation falls back into the oceans or onto land, where, due to gravity, the precipitation flows over the ground as surface runoff. A portion of runoff enters rivers in valleys in the landscape, with streamflow moving water towards the oceans.
Not all runoff flows into rivers, though. Much of it soaks into the ground as infiltration. Some of the water infiltrates into the ground and replenishes aquifers (saturated subsurface rock), which store huge amounts of freshwater for long periods of time. Some infiltration stays close to the land surface and can seep back into surface-water bodies (and the ocean) as groundwater discharge, and some groundwater finds openings in the land surface and emerges as freshwater springs. Yet more groundwater is absorbed by plant roots to end up as evapotranspiration from the leaves. Over time, though, all of this water keeps moving, some to reenter the ocean, where the water cycle begins all over again.
A Gertrude must have incorrectly measured the amount of rainfall over the last month.
B Gertrude and Paola could both be correct. Water in the lake will continue to evaporate, so it is unlikely that rainfall is equal to the lake’s water level increase.
C Gertrude and Paola must have both incorrectly measured rainfall and water level. They need to repeat this data collection next month and make sure they are measuring correctly.
D Paola must have incorrectly measured the lake’s water level over the last month.
The correct answer is B.
Explanation:
Gertrude and Paola could both be correct. Water in the lake will continue to evaporate, so it is unlikely that rainfall is equal to the lake’s water level increase.
The water cycle is a continuous process. Rain will fall into the lake, but the lake will continue to experience evaporation over time. Changes in the lake’s water levels will not be equal to the amount of rainfall, because rainfall is additive whereas the lake’s water levels are a continuous measurement.
Additionally, some of the water in the lake also could have soaked into the ground through the process called infiltration. This would also explain the lake’s lower water level.
What factor determines the composition of an asteroid and, thus, its classification?
Asteroids
Asteroids, sometimes called minor planets, are rocky remnants left over from the early formation of our solar system about 4.6 billion years ago.
Most of this ancient space rubble can be found orbiting the sun between Mars and Jupiter within the main asteroid belt. Asteroids range in size from Vesta - the largest at about 329 miles (530 kilometers) in diameter - to bodies that are less than 33 feet (10 meters) across. The total mass of all the asteroids combined is less than that of Earth’s Moon.
Most asteroids are irregularly shaped, though a few are nearly spherical, and they are often pitted or cratered. As they revolve around the sun in elliptical orbits, the asteroids also rotate, sometimes quite erratically, tumbling as they go. More than 150 asteroids are known to have a small companion moon (some have two moons). There are also binary (double) asteroids, in which two rocky bodies of roughly equal size orbit each other, as well as triple asteroid systems.
The three broad composition classes of asteroids are C-, S-, and M-types. The C-type (chondrite) asteroids are most common, probably consist of clay and silicate rocks, and are dark in appearance. They are among the most ancient objects in the solar system. The S-types (“stony”) are made up of silicate materials and nickel-iron. The M-types are metallic (nickel-iron). The asteroids’ compositional differences are related to how far from the sun they formed. Some experienced high temperatures after they formed and partly melted, with iron sinking to the center and forcing basaltic (volcanic) lava to the surface. Only one such asteroid, Vesta, survives to this day.
A how dense they are
B how far they were formed from the Sun
C the timeframe they were formed
D forces of gravity from nearby planets
The correct answer is B.
Explanation:
The compositional differences of asteroids are determined by how far from the Sun they were formed. The classes of asteroids are determined by their composition. As stated in the passage, “The three broad composition classes of asteroids are C-, S-, and M-types. The C-type (chondrite) asteroids are most common, probably consist of clay and silicate rocks, and are dark in appearance. They are among the most ancient objects in the solar system. The S-types (“stony”) are made up of silicate materials and nickel-iron. The M-types are metallic (nickel-iron). The asteroids’ compositional differences are related to how far from the sun they formed.”
Which of the following compounds given in the table could be classified as acidic?
pH Scale
One way that scientists classify chemicals is by their pH values. The pH scale ranges from 0 to 14. It is based on the pH value of pure water, which is located in the middle of the scale and is considered to be neutral.
If a substance has a pH value below that of water, it is considered acidic. If a substance has a pH value above that of water, it is considered basic. The further a pH value is from neutral, the more acidic or basic it is.
A) B only
B) A and B only
C) A, C, and D only
D) C only
The correct answer is B.
Explanation:
The pH scale is as follows: 0-6.9 is acidic; 7.0 is neutral; 7.1-14 is basic. The lower the pH, the more acidic a substance is.
The higher the pH, the more basic (or alkaline) a substance is.
Compounds A and B are both acidic. Compound C is neutral. Compound D is basic.
Consider the following solution:
Savannah is making iced tea. She adds a little bit of sugar to her iced tea and it easily dissolves. She knows she can add more sugar to the solution, but she only likes her tea to be slightly sweetened.
Which of the following is the best way to describe Savannah’s tea?
Solubility Terms
The solubility of a solution is determined by measuring the maximum amount of one substance (called the solute) that can dissolve in a given amount of a second substance (called the solvent).
The table shows the classification levels that can be used to describe a solution:
A unsaturated
B saturated
C supersaturated
D hypersaturated
The correct answer is A.
Explanation:
A solution is called unsaturated when a solvent could still dissolve more solute at a given temperature. Since the tea could dissolve more sugar, this solution is unsaturated.
Bridger, Marci, and Davis are trying to make sense of the information displayed in the “US Primary Energy Consumption by Source and Sector, 2016.” Bridger says that the residential and commercial sector relies most heavily on coal. Marci says that the industrial sector relies most on natural gas. Davis says that the transportation sector relies most on petroleum.
Who is correct?
Energy sources are listed on the left side of the graph and the sectors that use these energy sources are listed on the right side of the graph.
The lines and arrows connecting the two sides of the graphic break down how each source was used by each sector.
A Bridger, Davis, and Marci are all correct.
B Bridger and Marci are correct, but Davis is not correct.
C Davis and Marci are correct, but Bridger is not correct.
D Only Marci is correct. Bridger and Davis are not correct.
The correct answer is C.
Explanation:
Davis and Marci are correct, but Bridger is not correct.
As Davis stated, the transportation sector relies most on petroleum. 92% of the transportation sector uses petroleum as its energy source.
As Marci stated, the industrial sector relies most on natural gas. 45% of the industrial sector uses natural gas as its energy source.
Bridger, however, was incorrect. The residential and commercial sector relies most on natural gas. 74% of the residential and commercial sector uses natural gas as its energy source.
Brenden and Hannah have just finished learning about photosynthesis. Brenden concludes that sunlight is necessary for photosynthesis to occur. Hannah concludes that oxygen is necessary for photosynthesis to occur.
Who is correct? Why?
Photosynthesis
Nearly all life on earth depends upon photosynthesis, a process used by plants, algae, and cyanobacteria to convert light energy into chemical energy. Pigment molecules within the organism capture energy from sunlight and, through a series of chemical reaction steps, use that energy to build glucose (C6H12O2) molecules from carbon dioxide (CO2) molecules. In this way, the organism is able to make and store its own food. Therefore, photosynthetic organisms are referred to as producers. In addition to providing a source of food for producers, photosynthesis also provides a source of food for most other organisms on earth: the consumers that eat producers or other consumers.
In plants and algae, photosynthesis takes place in organelles called chloroplasts. A typical plant cell contains about 10 to 100 chloroplasts. Although all cells in the green parts of a plant have chloroplasts, most are found in the plant’s leaves. Pigment molecules embedded within the chloroplast’s complex membrane system capture sunlight energy. Chlorophyll is the most abundant photosynthetic pigment in plants. Chlorophyll does not absorb the green portion of the visible light spectrum, but instead reflects it. This is the reason that most plants appear green. Besides chlorophyll, plants and algae also use other pigments such as carotenes and xanthophylls.
In addition to sunlight, water (H2O), and carbon dioxide (CO2) are also required for photosynthesis. Plants generally take up water through their roots, which then travels up through stems and into the leaves. Carbon dioxide from the air enters the plant through tiny pores in the plant’s leaves or stems called stomata.
As the reaction steps of photosynthesis take place within a plant or other photosynthetic organism, some of the sunlight energy that was captured by the pigment molecules becomes stored in the glucose molecules that are produced. In addition, oxygen (O2) is produced as a byproduct and is released into the environment.
A Both Brenden nor Hannah are correct. Sunlight and oxygen are both required for photosynthesis to occur.
B Brenden is correct. Without sunlight, photosynthesis would not occur.
C Hannah is correct. Without oxygen, photosynthesis would not occur.
D Neither Brenden nor Hannah are correct. Glucose is required for photosynthesis to occur.
The correct answer is B.
