The graph shows the average growth rate for

38 pairs of newborn rats. One of each pair was injected with anterior pituitary extract. The other member of each pair served as a control.

At 75 days, what was the average weight of the rats injected with pituitary extract?

The graph shows the average growth rate for 5.

38 pairs of newborn rats. One of each pair was

injected with anterior pituitary extract. The other

member of each pair served as a control.

Based on the graph, it can be correctly concluded

that the pituitary extract

The graph shows the relationship between the

weight of treated and untreated rats and the

Three pieces of apple were cut so that all were the same mass and shape. The pieces were placed in three di erent concentrations of sugar water. After 24 hours, the pieces were removed and their masses determined. The graph shown indicates the change in the mass of each piece.

The three points on the graph represent

The apparatus pictured as shown was set up to 8. determine the conditions under which an enzyme

acts. A narrow tube containing egg white was

placed in each test tube and then the tube was

lled with the liquid indicated. The test tubes were then incubated for one day. At the end of that period, it was discovered that the egg white at the ends of the narrow tube in test tube 2 had disappeared. The most reasonable conclusion that can be drawn from this investigation is that

A student reported that a wilted stalk of celery became crisp when placed in a container of ice water. The student's statement was based on

A student reported that a wilted stalk of celery became crisp when placed in a container of ice water. The student then suggested that water entered the stalk and made it crisp. This suggestion is considered to be

An experiment was designed to determine the

e ect of nitrates on plant growth. Two groups

of plants were grown under identical conditions, except one group was watered with a dilute nitrate solution and the other group received water without nitrates. In this investigation, the group of plants grown without added nitrates is known as the

Which sequence should be followed when

conducting a laboratory investigation?

The diagrams shown represent an investigation

concerning the growth of bean plants. The roots

of three identical bean plants were each placed

through a hole in covered tubes containing water

as shown in the diagrams. Nothing was done to

plant A. Vaseline was used to cover the upper

surface of the leaves of plant B. Vaseline was used

to cover the lower surface of plant C. The water

level of each tube was marked and the plants were

placed together near a window. After 24 hours,

the water level in each tube was measured.

Which tube represents the control for this

investigation?

A drug company tested a new medication before putting it on the commercial market. Pills without medication were given to 500 test subjects in group A and pills containing medication were given to 500 test subjects in group B. In this experiment, the individuals in group A served as the

An investigation was performed with honeybees to determine the average amount of nectar a bee carried in relation to the distance the flowers were from the hive. The following data were collected: 400 meters, 45 milligrams; 100 meters, 43 milligrams; 600 meters, 44 milligrams; 200 meters, 47 milligrams; 300 meters, 41 milligrams; 500 meters, 42 milligrams.

Which inference is best supported by the data collected?

In a scientific investigation, after the question is

defined, the next step is most likely

The number of meadow mice in a certain grassy field was determined each year from 1977 to 1989. The results are represented in the data table.

During which time period did the greatest change in the size of the population of meadow mice take place?

A student conducted an original, well-designed experiment, carefully following proper scienti c procedure. In order for the conclusions to become generally accepted, the experiment must

A student records his body temperature at 6:00 am and 6:00 pm each day for 30 days. He notices a trend in his temperature data and o ers a possible explanation. His explanation is known as

Inan experiment, the setup that provides a basis of comparison is known as

A field study was conducted to observe a deer 20. population in a given region over time. The deer

were counted at different intervals over a period

of 40 years. During this period of time, both

ranching and hunting increased in the study region. A summary of the data is presented in the table.

During which 10-year period did the greatest increase in the deer population occur?

In an investigation designed to determine the effect of the amount of water on plant growth, two groups of equal-sized bean plants of the same species were grown under identical conditions, except for the amount of water they were given. One group was watered with 200 milliliters of water once a day, while the other group was watered with 400 milliliters of water once a day. After several days, the heights of the plants were measured. It was determined that the plants watered with 400 milliliters of water once a

day showed more growth. The variable in this investigation is the

What is the first step of a scientific investigation?

A student used a compound microscope to obtain 23. data on leaf stomate density. The student observed

a small area of the lower epidermis of a leaf and

counted two stomates in the high-power field of

vision. The student then observed a small area of the upper epidermis of the same leaf and found no stomates in the high-power field of vision. After making these observations, the student should

For many years, scientists were uncertain about the function of repeated base sequences in DNA that did not code for proteins. Recently, investigations of plants indicated that the greater the number of speci c repeated base sequences a plant species contains, the larger the plant will be. The Atlantic Giant pumpkin, which can reach a weight of almost 1,000 pounds, was found to contain a large number of these repeated DNA sequences. Similar findings were observed in other large plants. Which statement is not valid based on the information?

A new concept that is tested in a scientific investigation is known as

As part of an investigation, 10 bean seedlings

in one setup were grown in the dark, while

10 seedlings in another setup were grown in sunlight. All other growth conditions were kept the same in both setups. The seedlings grown in the dark were white with long, slender stems. These seedlings eventually died. The seedlings grown in the sunlight were green and healthy. Which hypothesis was most likely being tested in this investigation?

The results of one experiment carried out by a research team would be considered valid if

Which sentence represents a hypothesis?

A large island in the Pacific Ocean supports isolated populations of two groups of frogs. The following observations of these frogs were recorded by scientists.

Which observation best supports the inference that these frogs belong to the same species?

The structural formulas shown represent certain organic compounds found in living cells.

A strand of RNA is a polymer made up of many repeating units of the compound represented by

Which formula represents a monosaccharide?

Which formula represents a molecule of glycerol?

Which letter indicates a molecule of disaccharide?

The diagram shown represents the building block of a large molecule known as a

A molecule of this substance may be formed as a result of the hydrolysis of a

Vegetable oils, such as corn oil, belong to which general class of organic substances?

A biochemist was given a sample of an unknown organic compound and asked to determine the class of organic compounds to which it belonged. The chart shown represents the results of biochemist's analysis of the sample. Based on these results, to which class of organic compounds did this sample belong?

Which organic molecule is represented by C₆H₁₂O₆ ?

The type of molecule represented by the formula C₆H₁₂O₆ is most likely a component of

Which structural formulas of organic compounds shown represent proteins?

Select the compound, chosen from the list below,

which is most closely associated with this

statement:

These molecules are added during the

process of hydrolysis and are removed during

dehydration synthesis.

Select the compound, chosen from the list below,

which is most closely associated with this

statement:

These molecules often function as coenzymes.

Not all human cells are capable of synthesizing all

the compounds required for life. Those compounds

that cannot be synthesized must be ingested.

These ingested compounds include

All carbohydrates are compounds that contain the elements

Select the nutrient, chosen from the list below, that is best described by the statement shown:

Saturated molecules of this nutrient, which may predispose humans to cardiovascular disease are solid at room temperature.

Select the nutrient, chosen from the list below, that is best described by the statement shown:

This nutrient can serve as an energy source or provide nondigestible materials that increase the amount of roughage in the human diet.

The products represented by letter A are

Which molecules belong in area A?

A list of life activities is given. Which sequence of these activities would most likely occur in humans during the processing of a single protein molecule?

Which is a characteristic of an enzyme?

Graph I shows the relationship between the 51. relative rates of activity of enzymes A and B and temperature. Graph II shows the relationship between the relative rates of activity of enzymes A and B and pH.

Under which conditions is enzyme A most effective?

The optimum environment for enzyme B is

Enzymes are similar to antibodies in that both

Which graph below best illustrates the pattern of

enzyme action rates when a specific substrate is

slowly added to a system with a fixed enzyme

concentration?

The distortion (change in shape) of enzyme molecules which occurs at high temperatures is known as

An enzyme-substrate complex may result from the

interaction of molecules of

The graph shown represents the rate of enzyme

action for gastric protease when this enzyme concentration is kept constant. The pattern of enzyme action shown in the graph most likely results from varying which experimental factor (x in the graph)?

A student placed a test tube containing a mixture of compounds into a beaker of water maintained at 30^◦C. A chemical reaction took place and was completed in 30 minutes. A second test tube containing an equal amount of the same mixture plus substance Y was placed in the same beaker of water. The chemical reaction in the second test tube was completed in less than one minute. Substance Y was most likely

Which letter indicates a substrate molecule in this reaction?

Stage II in the diagram most correctly represents

The area labeled X is known as

Glucose-1-phosphate can be rapidly converted to glucose-6-phosphate by the addition of phosphoglucomutase. In this reaction, the phosphoglucomutase acts as

The graph shows the relationship between the rate of enzyme action and pH for three enzymes: pepsin, urease, and trypsin.

The optimum environment for pepsin is

Urease is most effective at a pH of

Which of these enzymes function in the most similar pH range?

Which conclusion can be drawn concerning the 68.

enzymes whose activity is represented in the

graph?

Which substances may function as coenzymes?

The graphs here show the relative rates of action of a specific enzyme at different temperatures and pH values.

The optimum temperature for the action of this enzyme is closest to the normal temperature of

As the temperature increases from 30^◦C to 50^◦C, the rate of action of this enzyme

When this enzyme and its substrate are mixed with pure water, the rate of enzyme action could be increased most by adding the appropriate amount of

In which human organ would this enzyme most likely have the greatest rate of action with its substrate?

The enzyme intestinal protease is most active at a pH of 8.0 and a temperature of 37^◦C. The activity of this enzyme would most likely decrease with an increase in the

The diagram shown represents an enzyme-catalyzed reaction. The chemical process represented by this reaction is

The diagram shown is of the lock-and-key concept of enzyme action that occurs in humans and on your knowledge of biology. Which letter represents an enzyme?

The rapid decrease in the rate of enzyme action above 40^◦C in the human body is most likely due to

At very high temperatures, most enzymes do not increase the rate of the reactions that they regulate. The most probable reason for this lack of enzyme

activity is that high temperatures

Which enzyme regulates the reaction represented by the word equation shown?

lipid + water ---> fatty acids + glycerol

If the enzyme represented in the graph shown functions like most enzymes, which would be the best label for the vertical axis or the X - axis of the graph?

[Assume enzyme concentration remains constant.]

Which enzyme shows the greatest change in its rate of action with the least change in pH?

Which enzymes would function in a region of the human body that have a neutral pH?

The graph shown represents the relationship between pH and the rate of enzyme action for two enzymes, X and Y. Which statement best describes this pattern of enzyme action?

What is the optimum temperature for the enzyme?

Enzyme is a type of protein molecule. Which type of molecule is used for the synthesis of an enzyme?

Which graph best represents the effect of an increasing substrate concentration and a constant enzyme on the relative rate of enzyme action?

Which statement best expresses the information represented in the graph shown?

Hydrogen peroxide (H₂O₂) is a toxic by-product of cellular metabolism in aerobic organisms. The reaction shown occurs within the cells to prevent the accumulation of hydrogen peroxide.

In this reaction, catalase functions as an

Which factor most likely accounts for the change in the rate of enzyme action as the temperature increases from 40◦ C to 58◦ C ?

Which statement about enzymes is not correct?

The graph shows the activities of two enzymes at different pH ranges. The contents of the small intestine have a basic pH. When gastric protease enters the small intestine, the activity of this enzyme will most likely

Which pH value indicates the most acidic condition?

A condition caused by the lack of an enzyme needed to metabolize a specific amino acid is known as

A student placed groups of 50 seeds in a variety of temperatures ranging from 0 to 50 ^◦C. A difference in the rate of germination observed in the groups at different temperatures was most likely due to the effect of temperature on

Small molecules combine chemically and form large, complex molecules by a process known as

The process in which two monosaccharide molecules combine under certain conditions is an example of

Which statement concerning these structural formulas is correct?

The division of large, complex molecules into smaller, simpler molecules by adding water is accomplished by a process known as

Within a cell, which of the following elements is found in the greatest amount?

Which sugar solution was the first to liberate a measurable volume of CO₂?

Which is an example of an organic substance?

In addition to carbon and hydrogen, a molecule of vegetable oil contains

In the diagram, which substance belongs in area Z?