1.
Why is a mushroom considered a heterotroph?
Correct Answer
D. (4) It obtains nutrients from its environment.
Explanation
A mushroom is considered a heterotroph because it obtains nutrients from its environment. Unlike autotrophs that can produce their own food through photosynthesis or chemosynthesis, mushrooms rely on external sources for their nutrition. They obtain nutrients by decomposing organic matter in their surroundings, such as dead plants or animals. This process is known as saprophytism, and it allows mushrooms to absorb and break down complex organic compounds into simpler forms that they can use for energy and growth.
2.
Three days after an organism eats some meat, many of the organic molecules originally contained in the meat would be found in newly formed molecules of
Correct Answer
B. Protein
Explanation
After an organism eats meat, the organic molecules present in the meat are broken down during digestion. These molecules are then used by the organism to synthesize new molecules. Since meat is a source of protein, it is likely that many of the organic molecules would be used to form newly synthesized protein molecules in the organism's body. Therefore, the correct answer is protein.
3.
Which body system is correctly paired with its function?
Correct Answer
C. Circulatory—transports materials for energy release in body cells
Explanation
The circulatory system is responsible for transporting materials such as oxygen, nutrients, hormones, and waste products throughout the body. This system includes the heart, blood vessels, and blood. It delivers oxygen and nutrients to body cells, allowing them to produce energy through cellular respiration. Therefore, the circulatory system is correctly paired with its function of transporting materials for energy release in body cells.
4.
Which statement best explains why some cells in the reproductive system only respond to certain hormones?
Correct Answer
B. These cells have specific types of receptors on their membranes.
Explanation
Cells in the reproductive system only respond to certain hormones because they have specific types of receptors on their membranes. These receptors are designed to recognize and bind with specific hormones, allowing the cells to respond to the signals sent by those hormones. This specificity ensures that the reproductive system cells only respond to the hormones that are necessary for their proper functioning, while avoiding any potential harm or interference from hormones that are not relevant to their function.
5.
In the cell shown below, which lettered structure is responsible for the excretion of most cellular wastes?
Correct Answer
B. B
Explanation
Structure B is responsible for the excretion of most cellular wastes.
6.
What is the main function of a vacuole in a cell?
Correct Answer
A. Storage
Explanation
The main function of a vacuole in a cell is storage. Vacuoles are membrane-bound organelles that store various substances such as water, ions, nutrients, and waste products. They help maintain the cell's shape and turgor pressure, regulate osmotic balance, and store essential molecules and compounds needed for cellular processes. Vacuoles also play a role in detoxification by storing harmful substances. Therefore, the correct answer is storage.
7.
If 15% of a DNA sample is made up of thymine, T, what percentage of the sample is made up of cytosine, C?
Correct Answer
B. 35%
Explanation
If 15% of the DNA sample is made up of thymine (T), then the remaining 85% must be made up of the other three nucleotides: adenine (A), guanine (G), and cytosine (C). Since DNA always pairs thymine with adenine and cytosine with guanine, the percentage of cytosine would be the same as the percentage of guanine. Therefore, 85% divided by 2 equals 42.5%. However, since the question asks for the percentage of cytosine alone, the correct answer is 35%.
8.
Global warming has been linked to a decrease in the
Correct Answer
A. Size of the polar ice caps
Explanation
Global warming is the increase in the Earth's average temperature due to the accumulation of greenhouse gases in the atmosphere. This increase in temperature has caused the polar ice caps to melt, resulting in a decrease in their size. The melting of the polar ice caps has serious consequences, such as rising sea levels and loss of habitat for polar animals. Therefore, the decrease in the size of the polar ice caps is directly linked to global warming.
9.
Several structures are labeled in the diagram of a puppy shown below.
Every cell in each of these structures contains
Correct Answer
B. Identical genetic information
Explanation
The correct answer is "identical genetic information" because the question is asking about the contents of each cell in the labeled structures. While cells contain various molecules and organelles, the one thing that is consistent and identical in all cells is their genetic information, which is stored in the form of DNA. This genetic information determines the characteristics and functions of the cells and is passed on from generation to generation.
10.
A characteristic that an organism exhibits during its lifetime will only affect the evolution of its species if the characteristic
Correct Answer
B. Is due to a genetic code that is present in the gametes of the organism
Explanation
The correct answer is "is due to a genetic code that is present in the gametes of the organism." This is because the genetic code present in the gametes is passed on to the next generation during reproduction, allowing the characteristic to be inherited by future generations.
11.
Agriculturists have developed some varieties of vegetables from common wild mustard plants, which reproduce sexually. Which statement best explains the development of these different varieties of vegetables?
Correct Answer
A. Different varieties can develop from a single species as a result of the recombination of genetic information.
Explanation
The development of different varieties of vegetables from a single species is best explained by the recombination of genetic information. This means that through sexual reproduction, different combinations of genes are produced, leading to the creation of new varieties with unique traits. This process allows for genetic diversity and adaptation to changing environmental conditions, resulting in the development of different varieties within a species.
12.
The diagram below represents a technique used in some molecular biology laboratories.
This technique is a type of
Correct Answer
D. Genetic engineering
Explanation
The diagram shown represents a technique used in some molecular biology laboratories. This technique is not chromatography or gel electrophoresis, as those are separate techniques used in molecular biology. Direct harvesting is also not the correct answer, as it does not match the technique shown in the diagram. The correct answer is genetic engineering, as the diagram likely represents a process or method used in manipulating or modifying genes or DNA in a laboratory setting.
13.
A species of bird known as Bird of Paradise has been observed in the jungles of New Guinea. The males shake their bodies and sometimes hang upside down to show off their bright colors and long feathers to attract females. Females usually mate with the “flashiest” males. These observations can be used to support the concept that
Correct Answer
D. Behaviors that lead to reproductive success have evolved
Explanation
The observation of male Bird of Paradise displaying unusual courtship behaviors, such as shaking their bodies and hanging upside down, to attract females suggests that behaviors that lead to reproductive success have evolved. This is because the females tend to mate with the "flashiest" males, indicating that these behaviors are advantageous in terms of reproductive success. This supports the concept that certain behaviors have evolved over time to increase an organism's chances of successfully reproducing.
14.
Which statement concerning the evolution of species A, B, C, D, and E is supported by the diagram below?
Correct Answer
A. Species B and C can be found in today’s environments.
Explanation
The diagram supports the statement that species B and C can be found in today's environments because both species are depicted in the diagram. The diagram does not provide any information about the evolution or interbreeding of species A, D, and E, or the common ancestry of species A, B, and E. Therefore, the correct answer is that species B and C can be found in today's environments.
15.
The diagram below represents a process that occurs during human reproduction.
The process represented by the arrow will ensure that the
Correct Answer
D. Gametes contain half of the genetic information
Explanation
During human reproduction, the process represented by the arrow refers to meiosis. Meiosis is a type of cell division that occurs in the reproductive cells (gametes) and ensures that the resulting zygote contains a complete set of genetic information. This is achieved by reducing the number of chromosomes in the gametes by half, through two rounds of division. As a result, each gamete contains only half of the genetic information present in the other cells of the body. When the gametes fuse during fertilization, the zygote formed will have a complete set of genetic information, with half coming from each parent.
16.
Even though identical twins have the same genetic material, they may develop slightly different characteristics because
Correct Answer
C. Gene expression may be influenced by factors that switch genes on and off
Explanation
Identical twins have the same genetic material because they come from the same fertilized egg that splits into two embryos. However, they may develop slightly different characteristics because gene expression can be influenced by factors that switch genes on and off. These factors can be influenced by the environment, lifestyle choices, and other external factors, leading to differences in how genes are expressed and ultimately resulting in variations in characteristics between identical twins.
17.
What normally happens immediately after fertilization in sexual reproduction?
Correct Answer
D. Division of cells resulting in the development of an embryo from a zygote
Explanation
After fertilization in sexual reproduction, the zygote undergoes cell division, which leads to the development of an embryo. This division of cells is the initial step in the formation of a new organism. The specialization of cells to form a fetus from an egg occurs later in the development process, after multiple rounds of cell division and differentiation. The production of daughter cells with twice or half the number of chromosomes as the parent cell is characteristic of meiosis, which occurs during gamete formation, not immediately after fertilization.
18.
The human female reproductive system is represented in the diagram below.
Production of gametes and support of the fetus normally occur in structures
Correct Answer
C. 3 and 5
Explanation
Structures 3 and 5 in the human female reproductive system are the ovaries and the uterus, respectively. The ovaries are responsible for the production of gametes (eggs) through the process of oogenesis. The uterus, on the other hand, provides support for the fetus during pregnancy by allowing it to implant and grow. Therefore, both the production of gametes and the support of the fetus occur in structures 3 and 5.
19.
Essential materials needed for development are transported to a human fetus through the
Correct Answer
C. Placenta
Explanation
The placenta is a vital organ that develops during pregnancy and acts as a connection between the mother and the fetus. It allows for the exchange of nutrients, oxygen, and waste products between the mother's blood supply and the developing fetus. Through the placenta, essential materials needed for development, such as nutrients and oxygen, are transported to the fetus. Therefore, the placenta is responsible for providing the necessary materials for the development of the fetus.
20.
The failure to regulate the pH of the blood can affect the activity of
Correct Answer
A. Enzymes that clot blood
Explanation
The failure to regulate the pH of the blood can affect the activity of enzymes that clot blood. Enzymes play a crucial role in the blood clotting process, as they help convert fibrinogen into fibrin, which forms a mesh-like structure to stop bleeding. If the pH of the blood is not properly regulated, it can disrupt the enzymatic reactions involved in blood clotting, leading to impaired clot formation and potential complications in wound healing and stopping bleeding.
21.
Young birds that have been raised in isolation from members of their species build nests characteristic of their species. This suggests that the nest-building behavior is
Correct Answer
A. Genetically inherited from parents
Explanation
The fact that young birds raised in isolation from their species still build nests characteristic of their species suggests that nest-building behavior is genetically inherited from parents. This means that the ability to build nests is passed down through genes from one generation to the next, rather than being learned by watching other birds or being influenced by the type of food the bird eats.
22.
Some people with spinal cord injuries do not sweat below the area of the injury. Without the ability to sweat, the human body temperature begins to rise. Which statement would best describe this situation?
Correct Answer
D. Dynamic equilibrium is disrupted.
Explanation
When people with spinal cord injuries are unable to sweat below the area of the injury, their body's ability to regulate temperature through sweating is disrupted. Sweating helps to cool down the body when it gets too hot. Without this mechanism, the body's dynamic equilibrium, which refers to the balance and stability of internal conditions, is disrupted. This disruption can lead to an increase in body temperature, as the body is unable to cool down effectively.
23.
Decomposers are necessary in an ecosystem because they
Correct Answer
D. Make inorganic materials available to plants
Explanation
Decomposers are necessary in an ecosystem because they make inorganic materials available to plants. Decomposers break down dead organic matter and waste products, releasing nutrients such as nitrogen, phosphorus, and potassium into the soil. These nutrients are then absorbed by plants, allowing them to grow and thrive. Without decomposers, organic matter would accumulate and nutrients would remain locked up, making it difficult for plants to obtain the essential elements they need for survival.
24.
A manatee is a water-dwelling herbivore on the list of endangered species. If manatees were to become extinct, what would be the most likely result in the areas where they had lived?
Correct Answer
B. Certain producer organisms would become more abundant in these areas.
Explanation
If manatees were to become extinct, certain producer organisms would become more abundant in the areas where they had lived. Manatees are herbivores and play a crucial role in maintaining the balance of the ecosystem by consuming large amounts of aquatic vegetation. With their absence, the producer organisms that they used to feed on would not be consumed as much, leading to an increase in their population. This would result in a shift in the composition and abundance of species in these areas, affecting the biodiversity.
25.
A serious threat to biodiversity is
Correct Answer
A. Habitat destruction
Explanation
Habitat destruction is a serious threat to biodiversity because it involves the loss or degradation of natural habitats, leading to the displacement or extinction of species. When habitats are destroyed, organisms lose their homes and sources of food and shelter, disrupting their survival and reproduction. This can result in a decline in biodiversity as certain species are unable to adapt or find suitable alternatives. Additionally, habitat destruction can also lead to the fragmentation of ecosystems, making it difficult for species to migrate or disperse, further impacting their populations.
26.
Which action will result in the greatest decrease in rain forest stability?
Correct Answer
C. Cutting down all the trees for lumber
Explanation
Cutting down all the trees for lumber would result in the greatest decrease in rainforest stability because it would lead to deforestation, which has severe ecological consequences. Trees play a crucial role in maintaining the stability of rainforests as they provide habitat for numerous species, regulate the water cycle, and contribute to the overall health of the ecosystem. Removing all the trees for lumber would disrupt these essential functions, leading to the loss of biodiversity, soil erosion, and increased vulnerability to climate change.
27.
One way that humans could have a positive impact on local environments is to
Correct Answer
B. Use resources that are renewable
Explanation
Using resources that are renewable means utilizing resources that can be replenished naturally over time, such as solar energy, wind power, or sustainable forestry. By doing so, humans can reduce their dependence on non-renewable resources like fossil fuels, which have a negative impact on the environment. This approach promotes sustainability and helps to preserve local environments for future generations.
28.
Which statement provides evidence that evolution is still occurring at the present time?
Correct Answer
C. New varieties of plant species appear more frequently in regions undergoing climatic change.
Explanation
The statement "New varieties of plant species appear more frequently in regions undergoing climatic change" provides evidence that evolution is still occurring at the present time. This is because the appearance of new plant varieties indicates that there is a process of genetic change and adaptation happening in response to the changing climate. Evolution is a continuous process that occurs over long periods of time, and the emergence of new plant species suggests that organisms are adapting and evolving to survive in different environmental conditions.
29.
The diagram below represents the various stages of ecological succession in New York State.
If the ecosystem is not altered, which stage would be the most stable?
Correct Answer
D. Hardwood forest
Explanation
The hardwood forest stage would be the most stable because it is the final and most mature stage of ecological succession. At this stage, the ecosystem has reached a state of equilibrium and has established a diverse community of trees and plants. The hardwood forest provides a stable habitat for a variety of species and has a well-developed soil and nutrient cycle. It is less susceptible to disturbances and has a higher resilience to environmental changes compared to earlier stages such as grass, shrub, or pine forest.
30.
A clear plastic ruler is placed across the middle of the field of view of a compound light microscope. A row of cells can be seen under low-power magnification (100×).
What is the average length of a single cell in micrometers (μm)?
Correct Answer
C. 200μm
31.
The graph below represents the populations of two different species in an ecosystem over a period of
several years.
Which statement is a possible explanation for the changes shown?
Correct Answer
C. Species B is better adapted to this environment.
Explanation
Species B being better adapted to the environment is a possible explanation for the changes shown in the graph. This can be inferred because the population of species B is increasing while the population of species A is decreasing. This suggests that species B is able to thrive and reproduce more successfully in the given environment, leading to its population growth.
32.
A mineral supplement designed to prevent the flu was given to two groups of people during a scientific study. Dosages of the supplement were measured in milligrams per day, as shown in the table below.
After 10 weeks, neither group reported a case of the flu. Which procedure would have made the outcome of this study more valid?
Correct Answer
D. Test a third group that does not receive the supplement
Explanation
To make the outcome of this study more valid, it would be necessary to test a third group that does not receive the supplement. This would serve as a control group, allowing for a comparison to be made between the two groups that received the supplement and the group that did not. By having a control group, researchers can determine if the lack of flu cases in the two groups that received the supplement was due to the supplement itself or some other factor. This helps to eliminate confounding variables and strengthens the validity of the study.
33.
The diagram below shows a normal gene sequence and three mutated sequences of a segment of DNA.
Which row in the chart below correctly identifies the cause of each type of mutation?
Correct Answer
A. 1
34.
Because of an attractive tax rebate, a homeowner decides to replace an oil furnace heating system with expensive solar panels. The trade-offs involved in making this decision include
Correct Answer
A. High cost of solar panels, reduced fuel costs, and lower taxes
Explanation
The homeowner decides to replace the oil furnace heating system with expensive solar panels because of an attractive tax rebate. This means that the cost of the solar panels may be high, but the homeowner will benefit from reduced fuel costs and lower taxes in the long run.
35.
Which level includes organisms that receive their energy from level B?
Correct Answer
A. A
Explanation
Level A includes organisms that receive their energy from level B. This means that the organisms in level A are dependent on the organisms in level B for their energy needs. They may consume the organisms in level B directly or indirectly through a food chain or food web. This relationship between the levels shows the flow of energy through an ecosystem, with energy being transferred from one level to another.
36.
Which level includes organisms that get their energy exclusively from a source other than the organisms in this ecosystem?
Correct Answer
D. D
Explanation
Level D includes organisms that get their energy exclusively from a source other than the organisms in this ecosystem.
37.
The chart below compares the size of three structures: a gene, a nucleus, and a chromosome.
Based on this information, structure A would most likely be a
Correct Answer
D. Gene that is part of structure B
Explanation
Based on the given information, structure A is smaller than both structure B and structure C. Since a gene is typically smaller than a nucleus or a chromosome, it is likely that structure A is a gene that is part of structure B.
38.
The diagram below shows molecules represented by X both outside and inside of a cell.
A process that would result in the movement of these molecules out of the cell requires the use of
Correct Answer
B. ATP
Explanation
ATP (adenosine triphosphate) is a molecule that provides energy for cellular processes. In order for molecules to move out of a cell, energy is required to overcome the concentration gradient. ATP can be hydrolyzed to ADP (adenosine diphosphate) and inorganic phosphate, releasing energy that can be used for active transport processes. Therefore, the use of ATP would be necessary for the movement of molecules out of the cell.
39.
Which statement most accurately predicts what would happen in the aquarium shown below if it were tightly covered and maintained in natural light for one month?
Correct Answer
D. The organisms would probably survive because materials would cycle.
Explanation
If the aquarium is tightly covered and maintained in natural light for one month, the organisms in the aquarium would probably survive because materials would cycle. This means that the natural processes of nutrient cycling, such as the breakdown of waste and the conversion of nutrients, would continue to occur within the closed system of the aquarium. This would provide the necessary resources for the organisms to survive and thrive. The other statements do not provide a logical explanation for the outcome in the given scenario.
40.
The data table below shows an effect of secondhand smoke on the birth weight of babies born to husbands and wives living together during pregnancy.
Based on these data, a reasonable conclusion that can be drawn about secondhand smoke during pregnancy is that secondhand smoke
Correct Answer
C. Slows the growth of the fetus
Explanation
Based on the data table, it can be observed that the babies born to husbands and wives who were exposed to secondhand smoke during pregnancy have a lower average birth weight compared to those who were not exposed. This suggests that secondhand smoke slows down the growth of the fetus, leading to lower birth weights.
41.
After the Aswan High Dam was built on the Nile River, the rate of parasitic blood-fluke infection doubled in the human population near the dam. As a result of building the dam, the flow of the Nile changed. This changed the habitat, which resulted in an increase in its population of a certain aquatic snail. The snails, which were infected, released larvae of the fluke. These larvae then infected humans.
42 This situation best illustrates that
Correct Answer
B. The influence of humans on a natural system can have unpredictable negative impacts
Explanation
The given situation of the Aswan High Dam and the increase in parasitic blood-fluke infection near the dam demonstrates that the influence of humans on a natural system can have unpredictable negative impacts. The construction of the dam led to changes in the flow of the Nile, which in turn affected the habitat and population of certain aquatic snails. These snails were infected and transmitted the fluke larvae to humans, resulting in an increase in infection rates. This example highlights the unintended consequences of human alteration on an ecosystem, emphasizing the unpredictability of the negative impacts.
42.
After the Aswan High Dam was built on the Nile River, the rate of parasitic blood-fluke infection doubled in the human population near the dam. As a result of building the dam, the flow of the Nile changed. This changed the habitat, which resulted in an increase in its population of a certain aquatic snail. The snails, which were infected, released larvae of the fluke. These larvae then infected humans.
The role of the snail may be described as a
Correct Answer
A. Host
Explanation
The snail plays the role of a host in this scenario. It provides a suitable environment for the larvae of the fluke to develop and multiply, ultimately leading to the infection of humans.
43.
A limiting factor unique to a field planted with corn year after year is most likely
Correct Answer
D. Soil nutrients
Explanation
A limiting factor unique to a field planted with corn year after year is most likely soil nutrients. This is because corn is a heavy feeder and requires a lot of nutrients to grow and produce a good yield. When corn is planted in the same field year after year, it depletes the soil of essential nutrients, such as nitrogen, phosphorus, and potassium. Without an adequate supply of these nutrients, the corn plants may suffer from stunted growth, reduced yield, and increased susceptibility to diseases and pests. Therefore, it is crucial to replenish the soil nutrients through fertilization or crop rotation to ensure healthy corn growth.
44.
The table below shows the abundance of some greenhouse gases in the atmosphere.
Identify the most abundant greenhouse gas and state one human activity that is a source of this gas. [1]
45.
The United States government does not allow travelers from foreign countries to bring plants, fruits, vegetables, animals, or other living organisms into this country. State one biological reason for keeping these out of the United States. [1]
46.
Birds colliding with aircraft either on the ground or in the air create problems for the Air Force. An organization known as BASH (Bird Aircraft Strike Hazard) studied the impact of birds colliding with aircraft. In 2001, there were 3854 bird collisions reported at a total cost to the Air Force of over 31 million dollars in damage—approximately eight thousand dollars per collision. August, September, and October were the busiest months with 1442 collisions. Nearly 50% of all these collisions occurred in the airfield environment, an environment that can most easily be controlled.
Is the problem with birds and aircraft limited to birds living on or near airport grounds? Support your answer using information from the passage. [1]
47.
Birds colliding with aircraft either on the ground or in the air create problems for the Air Force. An organization known as BASH (Bird Aircraft Strike Hazard) studied the impact of birds colliding with aircraft. In 2001, there were 3854 bird collisions reported at a total cost to the Air Force of over 31 million dollars in damage—approximately eight thousand dollars per collision. August, September, and October were the busiest months with 1442 collisions. Nearly 50% of all these collisions occurred in the airfield environment, an environment that can most easily be controlled.
State one possible reason that the greatest number of bird collisions occurs during August, September, and October. [1]
48.
The Control of Transpiration
Plants normally lose water from openings (stomates) in their leaves. The water loss typically occurs during daylight hours when plants are exposed to the Sun. This water loss, known as transpiration, is both beneficial and harmful to plants.
Scientists believe wind and high temperatures increase the rate of transpiration, but the size of each stomate opening can be regulated. Reducing the size of the openings during drought conditions may help reduce the dehydration and wilting that would otherwise occur.
A leaf may lose more than its own weight in water each day. Transpiration also lowers the internal temperature of the leaf as water evaporates. On hot days, temperatures in the leaves may be from 3° to 15°C cooler than the outside air. With stomates open, vital gases may be exchanged between the leaf tissues and the outside environment.
Researchers have also found many plants that use another response when leaf temperatures rise. Special molecules known as heat shock proteins are produced by plant cells and help to hold enzymes in their functional shapes.
50 State one way transpiration is beneficial to plants. [1]
49.
Identify two of the “vital gases” that are exchanged between leaf tissues and the outside environment. [1]
50.
Identify the specific leaf structures that regulate the opening and closing of stomates. [1]
Correct Answer
guard cells
guard cell
Explanation
The specific leaf structures that regulate the opening and closing of stomates are guard cells. Guard cells are specialized cells found in the epidermis of leaves. They surround and control the opening of the stomata, which are small pores on the leaf surface. When the guard cells are turgid, they swell and cause the stomata to open, allowing for gas exchange and transpiration. When the guard cells lose water, they become flaccid and the stomata close, preventing water loss and conserving moisture within the leaf.