Biology EOC Q/A

Which organism receives the least amount of energy from the producers? A. Hawk B. Rabbit C. Grasshopper D. Mouse

A. Hawk Available energy decreases as you go up a food chain or web. Secondary and tertiary consumers receive less energy than primary consumers.

Plant cells that are specialized for cell division are most likely found in what part of the plant? A. root tips B. leaf epidermis C. stem epidermis D. vascular tissue

A. root tips As plant roots grow, the cells in their tips undergo constant mitosis to produce new tissue.

Which of the following describes a way that a person's health can be affected by heredity? A. A person with a family history of obesity is more likely to catch a common cold. B. A person with a family history of high blood pressure is more likely to have heart disease. C. A person with a family history of obesity is less likely to enroll in a weight loss plan. D. A person with a family history of cancer is less likely to be screened for cancer.

B. A person with a family history of high blood pressure is more likely to have heart disease. Family history can affect a person's health in some areas by making them more likely to contract certain diseases. The genes that code for some diseases are hereditary, and can be passed from generation to generation.

The way that crimes are solved today was affected by which of the following technologies? A. gene therapy B. DNA fingerprinting C. genetic testing D. Genetic modification

B. DNA fingerprinting Even a tiny section of a person's DNA, left behind at a crime scene can be multiplied many times to make identification possible.

Whaling was a very profitable profession until whale populations crashed. The global community came together to enact a ban on whaling. However, Japan and Norway have not agreed to stop whaling. Which of the following is the most likely consequence of their decision? A. The whale populations are bouncing back very successfully and are unaffected by Japan and Norway continuing to whale. B. The whale populations are not rebounding as quickly as they might if all of the countries agreed not to hunt whales. C. The whale populations have mutated into new kinds of organisms. D. The whales are getting better at avoiding capture.

B. The whale populations are not rebounding as quickly as they might if all of the countries agreed not to hunt whales. All countries must work together to prevent major human impact on fragile ecosystems and populations of organisms.

What is the term for a strong response to a harmless antigen in the environment? A. cell-mediated immunity B. an allergy C. inflammatory response D. an autoimmune disease

B. an allergy Reactions to allergens release histamines which cause non-specific responses such as inflammation.

A community is concerned about the water quality of a nearby lake. Increased sedimentation in the lake is endangering the native habitat. The increased sedimentation is most likely caused by which of the following? A. trees planted along the shore of the lake B. construction of homes along the lake C. the amount of sunlight on the lake D. the amount of fish in the lake

B. construction of homes along the lake When homes are constructed, trees and plants are removed. Under natural conditions, trees and plants help to secure the soil and prevent erosion and sedimentation in lakes and rivers.

Which structure in the leaf controls the opening and closing of the stoma? A. cuticle B. epidermis C. guard cell D. spongy mesophyll

C. Guard cells Guard cells surround stomata and control their opening and closing. The stomata are the site of gas exchange in leaves, a process called transpiration.

Which of these organisms would most likely be found at the top of an energy pyramid? A. clams - a primary consumer B. sardines - a primary consumer C. sharks - a secondary consumer D. kelp - a primary producer

C. sharks - a secondary consumer Energy pyramids show the amount of available energy with the lowest levels having the most energy. Producers are found at the bottom of the pyramid, while secondary consumers would be found at the top.

In which way are photosynthesis and cellular respiration different? A. Cellular respiration stores ATP, while photosynthesis releases ATP. B. Cellular respiration produces oxygen, while photosynthesis uses oxygen. C. Photosynthesis releases energy, while cellular respiration stores energy. D. Photosynthesis used carbon dioxide, while cellular respiration produces carbon dioxide.

D. Photosynthesis used carbon dioxide, while cellular respiration produces carbon dioxide. The reactants of photosynthesis are the products of cellular respiration.

How does the predator-prey relationship affect a population? A. The predators and prey are in competition with each other. B. Usually either the predator or the prey will become extinct. C. The predator species usually has exponential growth. D. The relationship controls the population size of both species.

D. The relationship controls the population size of both species. The predators keep the prey population under control and the size of the population of prey limits the amount of predators an ecosystem can support.

Which gas is removed from the atmosphere during photosynthesis? A. hydrogen B. oxygen C. nitrogen D. carbon dioxide

D. carbon dioxide The reactants of photosynthesis are carbon dioxide and water.

What is the body's first line of defense against infection by foreign organisms? A. antibodies B. lymph nodes C. white blood cells D. the skin

D. the skin The skin is the first line of defense against foreign organisms. It acts as a non-specific barrier to water and air-borne infectious agents.

Which technology below would probably be the most important to a person who had diabetes and had to take insulin every day? A. testing parents for genetic disorders before they have children B. engineering fruits and vegetables that resist insects and other pests C. developing ways to identify criminals through DNA fingerprinting D. using recombinant DNA to produce human hormones from bacteria

D. using recombinant DNA to produce human hormones from bacteria Insulin is a hormone used to regulate blood sugar levels. It is essential to the correct functioning of the body. If bacteria can create insulin, this hormone will be easier for diabetics to get.

Which of the following best describes the connection between cardiovascular disease and age? A. As people age, their blood vessels become more elastic leading to less cardiovascular disease. B. As people age, the heart becomes more efficient with each pump, increasing cardiac output. C. As people age, blood pressure decreases leading to more cardiovascular disease. D. As people age, plaque builds up in the arteries increasing vessel resistance, which leads to disease.

D. As people age, plaque builds up in the arteries increasing vessel resistance, which leads to disease. This condition is called atherosclerosis, where the walls of the arteries become thick and inflexible. Atherosclerosis increases resistance in the blood vessels leading to high blood pressure.

Complete burning of plant material returns carbon primarily to the A. herbivores. B. water. C. vegetation. D. atmosphere.

D. Atmosphere When plant material is burned, carbon is released as carbon dioxide, which enters the Earth's atmosphere.

How do human diseases caused by bacteria and diseases caused by viruses react to antibiotics? A. Neither responds to antibiotics. B. Both respond to antibiotics. C. Viral diseases respond to antibiotics; bacterial diseases do not. D. Bacterial diseases respond to antibiotics; viral diseases do not.

D. Bacterial diseases respond to antibiotics; viral diseases do not. There is no known treatment for viral infections. The best defense against a pathogenic virus is a vaccination, which prevents infection if given before exposure to the virus.

Which statement describes the role of flowers in plant survival? A. Flowers can absorb carbon dioxide for sugar production. B. Flowers produce oxygen through cellular respiration. C. Flowers contain cells that carry out photosynthesis. D. Flowers contain cells that produce gametes.

D. Flowers contain cells that produce gametes. Flowers are the reproductive organs of plants.

Which of the following is true of a zygote? A. It forms into a blastocyst B. It is an unfertilized egg C. It produces haploid male gametophytes D. It is made up of only one cell

D. It is made up of only one cell The zygote is a fertilized egg. It is the first cell of a human embryo and contains the same amount of genetic information as all other somatic cells.

The northern elephant seal was almost hunted to extinction in the 1800s. By the late 1890s, approximately one hundred seals were left, reducing the gene pool of the population. What will be the consequence of this reduction? A. Competition within the population will increase. B. The surviving elephant seals will be better able to adapt. C. Inbreeding will be less frequent among the remaining population. D. The elephant seals will be more vulnerable to environmental change

D. The elephant seals will be more vulnerable to environmental change. The more genetic variation a population has, the more easily the population can deal with environmental change. If the gene pool decreases, genetic variation decreases

In what way did gene therapy, the replacement of a faulty gene with a normal one, stimulate medical research? A. New medications had to be developed and tested. B. The effects of viral DNA had to be studied. C. The way in which DNA replicates had to be determined. D. The genes on each chromosome had to be mapped and described.

D. The genes on each chromosome had to be mapped and described. The human genome project mapped out each gene of humans making gene therapy possible.

The cambuim is a section of cells in a plant that can become either part of the xylem or phloem, depending on the growth and needs of the plant. If the cambium of a particular plant was damaged, what would be the most likely effect on the plant? A. The plant would lose its ability to carry out photosynthesis. B. the plant would have uncontrolled growth. C. The plant would not experience any change in physiology. D. The plant would not be able to transport nutrients and water.

D. The plant would not be able to transport nutrients and water. The xylem and phloem are responsible for the transportation of nutrients, and water throughout the plant. If cambium cells were damaged, the plant would not be able to make xylem and phloem.

Which of the following best explains the difference in the amount of available energy in the trophic levels of the desert ecosystem? A. There is less energy available in the producers because their tissues are less dense than those at higher trophic levels. B. There is more energy available in the second trophic level because less energy is needed for hunting compared to the higher trophic levels. C. There is more available energy in the birds of prey because they have greater muscle mass for storing energy than organisms in lower trophic levels have. D. There is less available energy in the fourth trophic level because of the loss of energy through metabolism in each of the lower trophic levels

D. There is less available energy in the fourth trophic level because of the loss of energy through metabolism in each of the lower trophic levels. Each successive trophic level contains about 10% of the available energy from the previous trophic level. The other 90% is lost as heat to the atmosphere through metabolism by the organisms in that level.

White blood cells are an important part of the human immune response. Two types of white blood cells, neutrophils and macrophages, act as phagocytes. Phagocytes perform which of the following functions in the human body? A. They produce antibodies. B. They bind to antigens and develop into plasma cells. C. They form a barrier against pathogens. D. They engulf and destroy bacteria.

D. They engulf and destroy bacteria. Phagocytes are whole cells that capture invading cells or pieces of cells by surrounding and engulfing them. Once the invading cell is inside the phagocyte it is killed by enzymes.

If the xylem in a young tree is damaged, which process is first affected? A. performing photosynthesis B. transporting sugar to the roots C. transporting water to the leaves D. absorbing water from the soil

D. absorbing water from the soil Xylem carries water and nutrients from the soil, up into the leaves. The water is used to carry out photosynthesis, the products of which are sugar and oxygen.

Which of the following is a limiting factor in a population of organisms. A. reproductive replacement B. life spans of the members C. fluctuations in atmospheric temperature D. availability of food

D. availability of food The availability of food is a limiting factor in a population of organisms. If there is not enough food, some of the organisms will die and the population will decrease in number.

Which structure is represented by the letter D? A. scrotum B. testes C. prostate gland D. epididymides

D. epididymides The epidiymides lie adjacent to the testes and serve as a storage site for sperm on the way to the vas deferens

DDT and other pesticides used over 50 years ago are still affecting the environment today. Scientists have found these substances in recent glacier runoff. Glacier runoff occurs during the summer, when precipitation that has fallen on glaciers during the winter is released. Ice layers from existing glaciers have been analyzed. The results of this analysis show that the concentrations of DDT and other pesticides were highest about 10 years after the use of these substances was banned. This information shows that A. DDT and other pesticides cause glacier runoff during the summer. B. it takes humans over 50 years to analyze a glacier. C. precipitation helps to break down pesticides. D. the decision of one human generation may have an impact on future generations.

D. the decision of one human generation may have an impact on future generations.

The rate at which blood flows through the human body changes in response to many factors. Which statement describes one of these factors and its effect on blood flow? A. A high viscosity of blood causes an increased resistance in the blood vessels and leads to slow blood flow. B. A low blood pH decreases the rate of diffusion through the blood vessels and leads to slow blood flow. C. The changing of the shape of red blood cells to a crescent shape decreases resistance and lead to a faster blood flow. D. The narrowing of blood vessels increases pressure and leads to a faster blood flow.

A. A high viscosity of blood causes an increased resistance in the blood vessels and leads to slow blood flow. Viscosity refers to the thickness of blood. This thickness is caused by the number of red blood cells. Thick blood travels through blood vessels at a slower rate than thin blood.

A weightlifter is using heavy weights in short bursts for a competition. Because his muscle cells are not able to take in enough oxygen to make very much ATP the weightlifter begins to get fatigue in his muscles. Which of the following processes is most likely going on in the muscles of the weightlifter as he competes in his event? A. As the cells run out of oxygen they switch to anaerobic respiration, which allows the cell to make small amounts of ATP in the absence of oxygen. B. As the cells run out of oxygen, they die off gradually and the weightlifter's muscles have fewer contracting muscle cells. C. The cells will never run out of oxygen if the weightlifter is breathing. D. As the cells run out of oxygen, they will continue to make the same amount of ATP, since oxygen is not required to make ATP.

A. As the cells run out of oxygen they switch to anaerobic respiration, which allows the cell to make small amounts of ATP in the absence of oxygen. Anaerobic respiration is used by cells in the absence of ATP. This process converts sugars to alcohol and only creates a small amount of ATP compared to aerobic respiration.

Stem cell research has been a controversial subject in past years. What is the reason for this? A. Cells for study are often taken from human embryos. B. Stem cell techniques will not accomplish the intended purpose. C. The cells cannot be isolated. D. Replacement tissue will never be grown from a person's own stem cells.

A. Cells for study are often taken from human embryos. Embryos contain cells that are non-differentiated and can turn into any type of cell in the body. These cells could be used to create new tissues for people with diseases or malformations.

When an environment has reached its carrying capacity for a certain population, which of the following is true? A. Growth and immigration rate is equal to death and emigration rate. B. Growth and immigration rate is greater than death and emigration rate. C. Growth and immigration rate is less than death and emigration rate. D. Growth rate is exponential.

A. Growth and immigration rate is equal to death and emigration rate. Carrying capacity is the maximum population size of a species that can exist in a given environment given the resources.

When fertilizers run off farmland into streams and ponds, the nitrogen content of the water increases. This can lead to rapid growth of algae in a process called eutrophication. How can this process affect other organisms in the water? A. Oxygen is used up as algae is decomposed, reducing the amount available to other organisms. B. The water becomes better able to support aerobic organisms. C. The algae provide food for fishes and other organisms, leading to decreased algae populations. D. The extra nitrogen provides additional food for the other organisms, increasing their population.

A. Oxygen is used up as algae is decomposed, reducing the amount available to other organisms. Algal blooms, often caused by high levels of nitrogen in water lead to low dissolved oxygen levels and the death of many species in these ecosystems.

The removal of which of the following groups would cause an immediate decrease in the amount of energy flowing through the system? A. Producers B. Consumers C. Decomposers D. Inorganic nutrients

A. Producers Producers gather energy from the sun and convert it to useable molecules for consumers. Removing producers from any food chain or web will cause an immediate decrease in available energy.

What is immunity? A. The body's ability to produce cells that inactivate foreign cells or substances. B. The body's ability to regulate homeostasis through feedback loops. C. The body's ability to produce the "fight or flight" response. D. The body's ability to use the endocrine system to fight disease.

A. The body's ability to produce cells that inactivate foreign cells or substances. The immune system produces specific and non-specific responses to pathogens, and foreign cells and substances. This process helps maintain homeostasis in individuals.

How are cellular respiration and photosynthesis related, in terms of energy? A. The energy captured in photosynthesis is used to power cellular respiration. B. The energy transformed in cellular respiration is used to power photosynthesis. C. Photosynthesis and respiration perform the same task in terms of energy transformation. D. Energy is not involved in either photosynthesis or cellular respiration.

A. The energy captured in photosynthesis is used to power cellular respiration. Energy from the sun is used captured during photosynthesis and stored in the bonds of glucose molecules. During cellular respiration, this energy transferred to ATP molecules to be used to do work in the cell.

What is the main purpose of seeds in plants that have them? A. To protect and distribute the zygote. B. To entice animals to eat the plant. C. To be fertilized by other plants. D. To store water for the mother plant.

A. To protect and distribute the zygote. A seed contains a complete zygote wrapped in a seed coat. The seed's hard outer covering protects the seed until it can be dispersed, by wind or animals, to another location. This adaptation allows for a wider distribution of seed plants than those that do not have seeds.

Which of the following factors would most directly affect blood flow through the circulatory system? A. blood pressure B. blood sugar C. respiratory rate D. outside temperature

A. blood pressure The factors that most directly affect blood flow are blood pressure, blood volume, resistance and activity level.

The presence of wastes, such as plastic bags and motor oil, in lakes and streams miles away from developed areas suggests that A. ecosystems are interconnected and human action can alter ecosystem equilibrium. B. recycling programs have failed to conserve biotic resources. C. natural processes can alter ecosystem stability. D. direct harvesting practices have led to irreversible destruction of ecosystems

A. ecosystems are interconnected and human action can alter ecosystem equilibrium. Human impacts on the environment can be far-reaching. What we do in our own area of the Earth, can effect what happens in other areas as well.

The framework of organic molecules essential to all organisms is composed mainly of carbon atoms. Which processes are involved in the cycling of carbon within an environment? A. photosynthesis and respiration B. evaporation and condensation C. transcription and translation D. diffusion and transpiration

A. photosynthesis and respiration Photosynthesis captures carbon dioxide from the atmosphere and converts it to glucose. Cellular respiration converts glucose to carbon dioxide.

New fuels are being produced by converting corn and grasses into compounds containing alcohols that can be broken down for energy in various engines. The purpose of this research is to A. reduce the use of nonrenewable resources. B. increase the rate of air pollution. C. reduce the rate of homeostasis in organisms. D. cause a loss of biodiversity in the rain forests.

A. reduce the use of nonrenewable resources. The use of nonrenewable resources has negative effects for many ecosystems as well as human beings. New ways to use renewable resources for energy are now being developed.

The pH of the water in several lakes in Norway and Sweden had decreased to below 5.0 due to an increase in acid rain. Which of the following is most likely to happen in these lakes? A. the decline of several fish populations B. an increase in numbers of fish C. an increase in the amount of primary producers D. increased predator-prey relationships

A. the decline of several fish populations Fish are sensitive to changes in pH and would experience a decrease in numbers if a shift in the pH of the water occurred.

Abnormalities present in the cells that line the uterus may prevent the production of offspring by directly interfering with which process? A. the development of the embryo B. the differentiation of gametes into zygotes C. the secretion of estrogen by the ovary D. the production and release of egg cells

A. the development of the embryo The uterus is the site of implantation and development of the human embryo.

A strip mining company wants to lease some land that is currently part of a national park. They promise to reclaim the land should any minerals be mined from the area, and they are willing to pay top dollar for the rights. As an ecologist, what factors would you raise with the local government? A. the threat to local biodiversity B. management of the land after the company leaves C. the new jobs that would be created D. the increased traffic in the area

A. the threat to local biodiversity Any time land is modified from its original natural state, the local organisms will be affected.

Sperm are created through meiosis in an area of the testes called the seminiferous tubules. Through which structure do the sperm travel to exit the testes? A. vas deferens B. seminiferous tubules C. scrotoum D. epididymis

A. vas deferens The vas deferens leads out of the testes. Here sperm are mixed with fluids to nourish and protect them. This mixture is called semen and travels out of the urethra into the vagina for fertilization of the egg.

Salt water is an abundant resource but unusable for irrigation and drinking. As demands on freshwater sources increase, the use of desalination processes to remove salt from ocean water is increasing. A concern of desalinating water is the large amounts of recovered salts that are returned to the ocean. Which of the following describes the most likely impact of desalination on the surrounding ocean environment? A. Methane gas would pollute the ocean environment as shoreline organisms begin to die and decay. B. Alteration in ocean salt levels would cause loss of species and unbalanced populations in marine food webs. C. Nonrenewable resources in the ocean environment would become depleted and upset the ecosystem's balance. D. Increased levels of salts and minerals in the ocean would result in overpopulation of marine bivalves due to strengthened shells.

B. Alteration in ocean salt levels would cause loss of species and unbalanced populations in marine food webs. Any change in abiotic factors (such as salinity) will have effects on the organisms in an ecosystem.

Which statement describes how photosynthesis and cellular respiration are interrelated? A. Oxygen is produced during cellular respiration and stored during photosynthesis. B. Carbon dioxide and water released by cellular respiration are used in photosynthesis. C. Photosynthesis releases the energy that is stored during the process of cellular respiration. D. Glucose is used during cellular respiration to produce food that is broken down during photosynthesis.

B. Carbon dioxide and water released by cellular respiration are used in photosynthesis. The products of cellular respiration (CO2 and H2O) are the reactants of photosynthesis. The overall equations for photosynthesis and cellular respiration are the reverse of each other.

Terrestrial plants have stomata on the surface of their leaves. Stomata are surrounded by two guard cells that change shape in response to environmental factors and open or close the stoma. Which of the following best explains how the structure of the leaf is used in processes that occur in plants? A. Water enters the plant through the surface of the leaf for transpiration B. Gases for photosynthesis are exchanged through the surface of the leaf. C. Energy for cellular reproduction is absorbed through the surface of the leaf. D. Carbon dioxide enters the plant through the surface of the leaf for cellular reproduction.

B. Gases for photosynthesis are exchanged through the surface of the leaf. Gas exchange in leaves is called transpiration and occurs through the stomata.

Why does ice stay at the top of oceans instead of sinking to the bottom? A. Ice is colder than liquid water. B. Ice is less dense than liquid water. C. Ice is more dense than liquid water. D. Ice is warmer than liquid water.

B. Ice is less dense than liquid water. As water freezes, its molecules spread apart into a specific arrangement that makes frozen water less dense than liquid water.

What function does ATP carry out in living things? A. It aids in protein folding and coiling. B. It is used to capture and transfer energy. C. It identifies DNA start sequences for transcription. D. It helps maintain the fluidity of cell membranes.

B. It is used to capture and transfer energy. ATP is the "energy currency" of cells. Energy is stored in the bonds of this molecule and is released to do work in the cell when the bonds are broken. ATP is created during cellular respiration.

What is the main function of leaves? A. Leaves provide support for growth and a place to store food. B. Leaves provide a place for photosynthesis to occur. C. Leaves absorb water and minerals and transport nutrients to the stem. D. Leaves create a barrier that prevents water in the plant's tissues from evaporating.

B. Leaves provide a place for photosynthesis to occur. Leaves contain chloroplasts, the site of photosynthesis in plants.

Why are there so few aquatic plants and phytoplankton that live at the bottom zones in the ocean? A. The ocean floor contains many decomposers. B. Most sunlight is absorbed before reaching these levels. C. Water is a limiting factor. D. The temperature in these zones is extremely low.

B. Most sunlight is absorbed before reaching these levels. Plants and phytoplankton are primary producers that rely on the sun to carry out photosynthesis. The bottom zones of the ocean have little to no light.

Two different species of bacteria are examined. Scientists find that species X always produces CO2 and H2O during cellular respiration. Species Y always produces ethyl alcohol and CO2. Which conclusion can be made from these observations? A. Only species Y is aerobic. B. Only species Y is anaerobic. C. Both species X and Y are aerobic. D. Both species X and Y are anaerobic.

B. Only species Y is anaerobic. Anaerobic cellular respiration converts sugars to ethyl alcohol and carbon dioxide in the absence of oxygen.

Which of the following statements is true about natural systems? A. Consumers form the bottom levels of both the energy pyramid and the biomass pyramid. B. Producers are at the bottom level of both the energy pyramid and the biomass pyramid. C. Producers are at the bottom of the energy pyramid, but at the top of the biomass pyramid. D. Consumers are at the bottom of the energy pyramid, but at the top of the biomass pyramid.

B. Producers are at the bottom level of both the energy pyramid and the biomass pyramid. Both the biomass pyramid and the energy pyramid have producers at the bottom. Producers account for most of the biomass and most of the available energy in any given ecosystem.

Which will most likely happen if the decomposers are removed from the carbon cycle? A. The amount of carbon dioxide in the atmosphere will increase. B. The amount of carbon dioxide in the atmosphere will decrease. C. The amount of carbon dioxide used by producers will increase. D. The amount of carbon dioxide needed by consumers will decrease.

B. The amount of carbon dioxide in the atmosphere will decrease. Decomposers release carbon into the atmosphere, so if they were removed less carbon would reach the atmosphere.

While genetic engineering has positive benefits, there are also concerns associated with widespread use of genetic engineering in agriculture. If many farmers begin to plant more genetically modified crops that have an increased tolerance to insects, which of the following may result? A. an increase in the use of pesticides B. a decrease in genetic diversity of the crops C. an increase in the contamination of the water supply D. a decrease in crop productivity

B. a decrease in genetic diversity of the crops Genetic modifications of organisms does not allow for random mutation in the genetic code. This random mutation is responsible for the genetic diversity seen in populations of organisms.

A plant species lives in an area with limited sunlight. Which physiological adaptation would be most useful to the plant? A. colorful flowers B. large leaves C. deep roots D. thin cuticle

B. large leaves Leave are the part of a plant that contains chloroplasts. Chloroplasts are structures that contain chlorophyll, a pigment that captures sunlight and allows the plant to make sugars. The larger the leaf surface a plant has, the more sunlight it can capture.

Water is often called the "universal solvent" because many substances can be dissolved in water. What property of water allows it to be such a versatile solvent? A. purity B. polarity and cohesion C. high heat capacity D. expansion upon freezing

B. polarity and cohesion Water molecules are polar. This means that they have slight positive and negatively charged ends. Water molecules are attracted to a wide variety of molecules because of those charges and thus, acts as a solvent for a variety of compounds.

In which of the following structures of the female human reproductive system is the blastocyst implanted during normal human development? A. ovary B. uterus C. vagina D. amniotic sac

B. uterus The blastocyst makes its way down the uterine tube and implants in the uterus.

Which of the following are abiotic factors that shape ecosystems? A. worms, plants and temperature B. wind, precipitation, and soil type C. niches, trees, and bacteria D. sunlight, mushrooms, and wind

B. wind, precipitation, and soil type Abiotic factors are those that are non-living.

A diagram representing the relationship between photosynthesis and cellular respiration is shown below. The numbered boxes in the diagram represent which of the following? A. 1 - water; 2 - nitrogen B. 1 - nitrogen; 2 - oxygen C. 1 - oxygen; 2 - carbon dioxide D. 1 - carbon dioxide; 2 - water

C. 1 - oxygen; 2 - carbon dioxide Photosynthesis by plants produces oxygen, which is then used by animals as a reactant in cellular respiration. The product of cellular respiration is carbon dioxide, which is used by plants in photosynthesis. And the cycle continues.

Many species of bacteria have become resistant to antibiotics because antibiotics have been so widely used. Now, bacteria that used to be killed by antibiotics are more difficult to treat. What is the best way to proceed in dealing with this public health problem? A. Antibiotics should no longer be used. B. Antibiotics should be made available to anyone without a prescription. C. Antibiotics should only be prescribed to people with bacterial infections. D. Anti-viral medications should now be used instead of antibiotics.

C. Antibiotics should only be prescribed to people with bacterial infections. Antibiotics are only useful against bacterial infections. When antibiotics are prescribed to individuals that do not have a bacterial infection, any bacteria they may have in their body can become resistant to the antibiotic and the resistant bacteria can multiply.

After an initial infection, B-cells recognize the measles virus. How is this helpful in human immune response? A. The B-cells use this recognition to defend the body against other pathogens, such as bacteria. B. The B-cells more quickly recognize and respond to any other virus that invades the body. C. The B-cells produce antibodies more quickly if the measles virus is encountered again. D. The B-cells transfer this recognition to T-cells, which will then devour the viruses.

C. The B-cells produce antibodies more quickly if the measles virus is encountered again. After an initial infection with a virus, B cells are able to recognize the virus and produce antibodies against it the second time. The person's reaction to the virus will be lessened.

The common brushtail possum is a marsupial native to Australia. This possum was introduced to New Zealand where it had no natural predators and had an abundant food supply. Which of these likely occurred a few years after the introduction of this possum to New Zealand? A. The possums became extinct. B. The possums developed shorter life spans. C. The possum population grew to a larger size. D. The possum population evolved into a different species.

C. The possum population grew to a larger size. With no natural predators, the possum population was allowed to grow unchecked.

The number of pythons found throughout Everglades National Park has increased in recent years. These huge snakes are not native to Florida and are believed to have been released into the wild by pet owners. Wildlife biologists have initiated attempts to capture and remove these pythons. Which statement best explains the biologists' reasons for removing these pythons from the Everglades? A. The pythons could upset the territorial boundaries of native organisms. B. The pythons could adapt to overcome diseases common to native snakes. C. The pythons could prey on native organisms and cause native population to decline. D. The pythons could begin to interbreed with native snakes and produce a more successful species.

C. The pythons could prey on native organisms and cause native population to decline. Introduced species often prey on native organisms declining their populations, sometimes to extinction.

Water is essential for life. Its special properties make water the single most important molecule in plant life. Which of the following properties of water enables it to move from the roots to the leaves of plants? A. Water expands as it freezes. B. Water is an excellent solvent. C. Water exhibits cohesive behavior. D. Water is able to moderate temperature.

C. Water exhibits cohesive behavior. Cohesion means that water molecules are attracted to each other and attracted to other substances, such as the walls of the xylem of plants. The water molecules behave this way because they are polar.

Large bodies of water, such as lakes and oceans, do not quickly fluctuate in temperature. What is the reason for this phenomenon? A. Water is an acid. B. Water is a versatile solvent. C. Water has a high heat capacity. D. Water acts as a buffer.

C. Water has a high heat capacity. Water can absorb a large amount of energy without a large rise in temperature. This is called heat capacity. As the sun shines on bodies of water, they absorb great amounts of its energy without a large fluctuation in temperature.

What is the human embryo called after the eighth week of development? A. a zygote B. an infant C. a fetus D. a morula

C. a fetus Human gestation is divided into two phases: the embryonic phase, which lasts through the 8th week, and the fetal stage, which lasts from 9 weeks until birth. Most major organs and structures are formed during the embryonic stage. The fetal stage is characterized by rapid growth.

Which of the following describes fertilization? A. cell differentiation to form a blastula B. formation of germ layers in a deuterostome C. a sperm joining an egg to form a zygote D. sperm and egg production

C. a sperm joining an egg to form a zygote Fertilization of the egg by a sperm happens in the uterine tube and the zygote begins to undergo mitosis to form a blastocyst

What causes blood pressure? A. cholesterol in the blood B. stress that exercise puts on heart muscle C. contraction of the ventricles in the heart D. removal of oxygen from the blood

C. contraction of the ventricles in the heart Blood pressure is caused by contraction of the ventricles of the heart and also by the elasticity of the arterial walls. When the heart contracts, blood pressure is the highest. This is called systolic pressure. When the heart is relaxed, blood pressure is lowest. This is called diastolic pressure. Some pressure is maintained in the vessels at all times, even with the heart is in diastole. This pressure is kept relatively constant by the elastic properties of the walls of the arteries.

In a process called transpiration, plants get rid of excess water through pores in the leaves called stomata. This excess water is then released into the atmosphere as part of the water cycle. Which of the following terms best describes how the released water enters the atmosphere? A. condensation B. precipitation C. evaporation D. capillary action

C. evaporation Water that is released by plants through transpiration evaporates into the atmosphere to rejoin the water cycle.

What kind of genetically modified crops would be most successful in wet-tropical countries that are overcrowded? A. crops that are drought- and pest-resistant B. high-yield crops that do not need a lot of sunshine C. high-yield crops that are pest-resistant D. crops that are drought-resistant and need a lot of sunshine

C. high-yield crops that are pest-resistant If space is limited, high-yield crops would be best. Wet-tropical climates are often plagued by pests so crops that are pest-resistant would do well in those climates.

The drinking of alcoholic beverages by a pregnant woman is harmful to the development of her fetus. This is most damaging early in a pregnancy because during this time A. the lungs of the fetus become functional. B. alcohol can easily enter the mouth of the fetus. C. many of the essential organs of the fetus are forming. D. the fetus cannot excrete wastes.

C. many of the essential organs of the fetus are forming. Most of the essential organs and structures of a fetus are formed in the first 9 weeks of gestation.

Data on the immigration and emigration of a fish species would be most helpful in determining which of the following? A. biological magnification B. interspecies competition C. population of the species D. predator-prey relationships

C. population of the species Population size is determined by births, deaths, immigration and emigration.

Data on the immigration and emigration of a fish species would be most helpful in determining which of the following? A. biological magnification B. interspecies competition C. population of the species D. predator-prey relationships

C. population of the species Population size is determined by births, deaths, immigration and emigration.

Although vaccines cannot be used to treat a person who is sick, they can help to prevent infections. Vaccinations tell the body to create "memory cells", which will function later to create antibodies against certain pathogens. When a person is vaccinated, what are they injected with? A. antibodies to a disease bacterium B. live, inactive viruses C. weakened viruses or antigens from the virus D. blood from a person who has had the disease

C. weakened viruses or antigens from the virus Vaccinations contain antigens or weakened viruses from specific infections. The viruses are too weak to cause illness in the patient, but strong enough to allow the body's immune system to create B cells against the virus. These "memory cells" are stored in the body until the person is exposed to the virus at which point, they will create antibodies against the virus.