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Which statement describes an activity of a decomposer?*
The calcium concentration in the root cells of certain plants is higher than in the surrounding soil. Calcium may continue to enter the root cells of the plant by the process of*
Homeostasis is maintained in a single-celled organism by the interaction of*
Within which structure of an animal cell does DNA replication take place?*
The shape of a protein is originally determined by the*
Plant cells can synthesize energy-rich organic molecules, and later break them down to extract that energy for performing life processes. These activities require direct interaction between the*
Selective breeding has been used for thousands of years to*
A deletion of a DNA segment alters a gene in a single skin cell of an individual. Which statement best describes a result of this mutation?*
Some goats have been genetically modified with a human gene that codes for a blood anticlotting factor. The anticlotting factor can then be extracted from the goat milk and used during surgery. To produce these genetically modified goats, scientists most likely*
Which characteristic is necessary for natural selection to occur in a species?*
Researchers use a variety of techniques to learn more about the function of a specific gene in an organism. In one type of experiment, called a loss-of-function experiment, the gene being investigated is eliminated. In a gain-of-function experiment, extra copies of the gene being investigated are inserted. The cell process most directly affected in both experiments is*
Plants are green because they contain the protein chlorophyll. A bucket was left on the lawn for one week. When the bucket was removed, the grass under the bucket had turned from green to a yellowish white color. This change is due to the interaction between the grass and*
Which statement describes a function of the human male reproductive system?*
Exposure to toxins during early stages of pregnancy is more likely to cause birth defects than exposure in late pregnancy because*
Although a liver cell and a muscle cell in a human developed from the same single cell, their appearance and functions are different. This is because the liver cell*
Sexual reproduction in a species usually results in*
As water flows downhill, its energy can be used to generate electricity. Later, this water may evaporate, fall as rain, and be used again to generate electricity in the same way. This explains why electricity generated with water is considered*
Scientists have found that although plants require light to carry on photosynthesis, very high levels of sunlight can kill some plants. This illustrates that many biochemical processes may occur*
A relationship between a consumer and producer is best illustrated by a*
The evolutionary pathways of several species are represented in the diagram below.
Which species was best adapted for survival in changing environmental conditions?*
The diagram below represents a microscopic view of blood.
Cell A protects the body by producing specific chemicals in response to pathogens. Cell A is*
The diagram below represents a change in guard cells that open and close pores in a plant.
This change directly helps to*
Which statement represents a characteristic of an ecosystem that is not likely to sustain itself?*
Which statement best explains why different plant species are found at different water depths as represented in the diagram below?
Some people see the benefit of wind energy as a clean alternative to fossil fuels for energy production. Others believe it is dangerous for migratory birds. These opinions best illustrate that decisions about alternate energy sources*
One way humans can promote the survival of organisms in an ecosystem is to*
Environmentalists are hoping to protect endangered organisms by calling for a reduction in the use of pesticides, because loss of these organisms would*
Which farming practice causes the least harm to the environment?*
Some bacteria are unable to survive unless a certain nutrient is present in their food supply. After exposure to ultraviolet radiation, some of these bacteria are able to synthesize this nutrient. This change is most likely due to*
Which action by humans could improve the quality of the air?*
Base your answers to questions 31 through 33 on the information below and on your knowledge of biology.
Euglena are single-celled organisms that live in ponds. All euglena have chloroplasts and can make their own food. They can also take in food from the environment. The diagram below represents a euglena.
An experiment was set up to determine the effect of nitrates, a pollutant, on the number of chloroplasts present in euglena. Five tanks were set up, each with euglena and a different concentration of nitrate solution: 0%, 0.5%, 1.0%, 1.5%, and 2.0%.
The tanks were placed in a sunny location where each tank received the same amount of light.
Which statement is a possible hypothesis for this experiment that could be supported by the results of this experiment?*
Which statement correctly identifies a variable in this experiment?*
Euglena can be classified as both*
Two methods of reproduction are represented in the diagram below.
How does the DNA in the offspring produced by these methods compare to the DNA in the original organism?*
Puppies are often given medicine to eliminate roundworms from their intestines. These worms consume some of the food the puppies have digested. The worms and the puppies represent a relationship known as*
The diagram below represents cells and hormones present in the human body.
Which statement correctly describes an interaction between the hormones and the cells?*
In the diagram below, which letter indicates the part of the cell that carries out a function most similar to a function of the human excretory system?
In a DNA sample, 15% of the bases are thymine (T). What percentage of the bases in this sample are adenine (A)?*
The graph below shows the results of an action of the enzyme catalase on a piece of meat. Evidence of enzyme activity is indicated by bubbles of oxygen.
Which statement best summarizes the activity of catalase shown in the graph?*
Which process is represented in the diagram below?
Base your answers to questions 41 and 42 on the diagram below and on your knowledge of biology. The diagram represents various levels of interaction between organisms in a prairie ecosystem.
If the amount of carbon dioxide in the atmosphere were to decrease, which organism in the diagram would be one of the first affected by this change?*
Which statement best describes a function of the molds, bacteria, and yeasts in this ecosystem?*
The diagram below represents the measurement of a biological specimen.
What is the approximate length of the specimen in millimeters?*
Base your answers to questions 44 through 48 on the information and data table below and on your knowledge of biology.
Diabetes is a disease characterized by consistently high blood glucose levels (at or above 126 mg/100 mL) as a result of hormone deficiency. For a study of diabetes, blood glucose levels from individual A and individual B were recorded each hour over a 5-hour period following a meal. The results are shown in the data table below.
Directions: Using the information in the data table, construct a line graph on the grid on the next page, following the directions below.
Mark an appropriate scale, without any breaks, on each labeled axis. *
Plot the data for individual A on the grid, surround each point with a small circle, and connect the points. 
Plot the data for individual B on the grid, surround each point with a small triangle, and connect the points. 
Which individual most likely has diabetes?*
Identify one hormone associated with the maintenance of blood glucose levels. 
Base your answers to questions 49 and 50 on the food chain and information below. The food chain involves organisms in Yellowstone National Park.
Grasses → Elk → Wolves
Wolves in the park were killed or driven off by humans in the 1920s and 1930s. In the winter of 1995, humans released 17 wolves from Canada into the park. A year later, 14 more wolves were released.
One possible reason that the wolves were released into the park was to*
After the wolves were released, the populations of some scavengers increased. This was most likely due to*
Base your answer to question 51 on the information below and on your knowledge of biology.
Dissolved oxygen (DO) can be found in an aquatic ecosystem and is often one factor that affects the size of populations of aquatic organisms. Water temperature is very important in determining the amount of DO in a water supply. The colder the temperature of the water, the more DO the water can hold.
State one possible reason why the biodiversity of an aquatic ecosystem could decrease if the water temperature were to increase. Support your answer. *
Base your answers to questions 52 through 54 on the passage below and on your knowledge of biology.
Polio is a virus that can cause paralysis or death. At its peak, the disease affected about 500,000 people a year worldwide before the development of an effective vaccine in 1955.
When the first polio vaccine was developed, it was tested in experiments using thousands of children as subjects. The children were injected with either the experimental vaccine or given a harmless injection without the vaccine. Only after these extensive tests was the vaccine finally accepted as being successful in preventing the disease.
Although, at this time, polio has been nearly eliminated in the Western Hemisphere, certain countries in the world still report new cases of the disease. Complete elimination of the disease can be achieved in these countries by vaccinating all of the children at the same time with the polio vaccine.
Identify the substance in the polio vaccine that makes it effective. *
Describe how the body responds to the vaccine, making it effective against a particular disease. *
Explain why the children in the first testing of the polio vaccine were not all given an injection of the experimental vaccine. *
Base your answer to question 55 on the information below and on your knowledge of biology.
In many areas, there are some small mammals whose fur color is influenced by temperature. In these animals, the trait for fur color is expressed only if the air temperature is above a certain level. In cold weather, when the ground is covered with snow, the trait is not expressed and the fur color is white.
Explain how the fur color change trait may help the small mammals survive. *
Base your answer to question 56-60 on the information below and on your knowledge of biology.
New varieties of organisms have resulted from human activities. These organisms have often led to problems in modern society. Two of these new varieties are listed below.
Antibiotic-resistant bacteria Pesticide-resistant insects
Select one of these varieties and discuss a problem associated with the development of this new variety of organism. In your answer, be sure to:
• identify the variety you selected
• identify one biological process by which a population of this variety may develop resistance 
• describe how this process is involved in the production of a population of resistant organisms 
• identify one problem caused by this resistance 
• state one solution to this problem 
• identify one possible negative effect of this solution 
Base your answer to question 61-63 on the passage below and on your knowledge of biology.
Green Tea & Acne
Green tea might be an effective treatment for acne, according to a study by researchers from Memorial Medical Center in the Philippines, reported by United Press International (UPI). The study showed that 3 percent green tea cream is comparable to 4 percent benzoyl peroxide in the treatment of moderate to severe acne.
Green tea has been shown to fight bacteria, reduce inflammation and decrease hormone activity — three characteristics that make the ancient tea an excellent candidate for an acne therapy.
In the study, one group of subjects applied benzoyl peroxide cream twice daily for 12 weeks and another used green tea extract cream twice daily for the same period. Patients received identical bottles of cream and were unaware of the type of treatment they were assigned. The researchers noted the green tea cream seemed to lighten patients’ [acne] and improve the overall appearance of their complexion.
The preliminary data suggest green tea extract cream causes fewer side effects than benzoyl peroxide treatment. Patients in the green tea group reported fewer cases of dry skin, itching and allergic responses. Azucena Arguelles, MD, a private practice dermatologist from Mountain View, CA, told UPI that the findings, while promising, are not yet substantial enough to change clinical practice.
Advance for Nurses, Nov. 10, 2003, “Green Tea & Acne,” www.advanceweb.com
Explain how this experiment can be used to develop a new treatment for acne. In your answer, be sure to:
• identify the organism targeted by green tea 
• identify one advantage of using green tea extract instead of benzoyl peroxide cream to treat acne 
• state one reason why, even though the findings are promising, they are “not yet substantial enough to change clinical practice” *
Base your answers to questions 64 and 65 on the information below and on your knowledge of biology.
Raw eggs and undercooked poultry may contain Salmonella bacteria. These bacteria can cause food poisoning by invading the cells lining the small intestine and producing a toxin that causes inflammation in the intestine. Symptoms usually appear 24 to 48 hours after the bacteria are ingested. Symptoms include fever, diarrhea, vomiting, dehydration, and abdominal pain that may last for several days.
Explain why Salmonella bacteria are described as pathogens. *
State one possible reason why the symptoms of food poisoning do not appear for 24 to 48 hours after eating food contaminated with Salmonella bacteria. *
A student was visiting a friend at her home. Her friend owned two cats. After playing with the cats for a while, the student began to sneeze. Her nose began to run and her eyes became red, watery, and itchy. It also became hard for her to breathe. A few minutes after leaving her friend’s home, the symptoms disappeared.
Provide a biological explanation for the symptoms the girl developed at her friend’s house. In your response, be sure to:
• identify the body system that was responsible for triggering the reaction she experienced 
• identify the type of reaction the student was most likely experiencing 
• state one reason why her symptoms are not likely due to an infectious agent *
Base your answer to question 69-72 on the information below and on your knowledge of biology.
Environmentalists and public health experts are warning the public about some chemicals that they come in contact with daily, such as PBDEs and phthalates. PBDEs are used to make children’s clothing flame retardant and phthalates are used to manufacture many plastic bottles, toys, and cosmetics. Both of these chemicals accumulate in the body and endanger health.
In one family tested, the young children had PBDE levels seven times that of their parents. These levels were two to three times the levels that caused thyroid problems in animals. Animal studies have shown that phthalates cause reproductive defects. Even at low levels, phthalates may contribute to infertility and impaired testes in males. Both chemicals can cause nervous system damage.
Biomonitoring is a technology used to test for levels of industrial chemicals found in the body. The technology is less than ten years old, but results from animal studies led some countries to ban PBDEs in 2004.
Presently, the United States EPA (Environmental Protection Agency) does not require chemical manufacturers to conduct human toxicity studies prior to approval for use. If concerns regarding risk or exposure arise during the approval process, the EPA can ask for additional testing. Additional testing occurs for approximately 10 percent of the new chemicals submitted each year. The EPA has also set up voluntary testing programs with major chemical manufacturers to rate some of the 3,000 most widely used chemicals.
The use of industrial chemicals, such as PBDEs and phthalates, provides both advantages and disadvantages. Discuss the disadvantages of using these chemicals. In your answer, be sure to:
• state one specific reason why public health officials are concerned about the use of these chemicals 
• identify the technique used to determine exposure levels to these chemicals in humans 
• state one possible reason why young children might have higher levels of exposure to these chemicals than do adults 
• state one possible reason why chemical manufacturers might participate in the voluntary testing programs set up by the EPA *
The materials represented in the diagram below were used in a laboratory activity.
These materials were used to carry out the technique known as*
A coverslip should be slowly lowered from a 45° angle onto a slide in order to*
A substance is most likely to diffuse into a cell when*
Base your answers to questions 76 and 77 on the information and data table below and on your knowledge of biology.
Five students design an experiment to answer the question: “How is heart rate affected by running?” Two chairs were set up at different ends of a large room. The pulse rate of each student was taken at rest just before running. Each of the five students ran between the chairs a different number of times. Their pulse rates were taken after running and the results are shown in the table below.
If a control group is not included in an experiment, it would be difficult to*
Explain how the change in heart rate helps to maintain homeostasis during exercise. *
Base your answers to questions 78 through 80 on the information below and on your knowledge of biology.
The sequences below represent the same portions of a DNA molecule from the same gene used by a student to study the relationship between two plant species. A biological catalyst that recognizes the CCGG site is used to cut the DNA molecules into pieces. The catalyst cuts the DNA between the C and G of the site.
Draw lines in the sequences below for species 1 and species 2 to show where the catalyst would cut the DNA. 
Species 1: T A C C G G A T T A G T T A T G C C G G A T C G
Species 2: T A C G G A T G C C G G A T C G G A A A T T C G*
Complete the data table below to show the results of the action of the catalyst. 
Are the two species of plants closely related? Support your answer. *
Base your answer to question 81 on the information and diagrams below and on your knowledge of biology.
The drawings below were made during a laboratory exercise in which a microscope was used to view slides of preserved protozoa. The microscope had a 10× eyepiece and two different objectives.
Which statement about the size of the organisms is correct?*
A student performed a gel electrophoresis experiment. The results are represented in the diagram below.
Compared to the fragments at the top of the gel, the fragments at the lower end are*
Base your answers to questions 83 through 85 on the diagram below and on your knowledge of biology.
On an island populated by both warbler finches and small tree finches, there is a significant decrease in the amount of animal food. Which finch population would decrease more? Support your answer. 
Finch population: ________________________________________*
Identify one species of finch that would most likely survive a sudden change in climate that destroyed seeds with small, thin coverings, leaving only seeds with large, thick coverings. Support your answer. 
Species of finch: ________________________________________*
An island has populations of both the cactus finch and sharp-billed ground finch. Explain how these finches can live on the same island even though these finches have similar beaks and both eat plants. *