AP Bio Practice Problems

An experiment to measure the rate of respiration in crickets and mice at 10 degree C and 25 degree C was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O^2 consumed per gram of organism over several five-minute trials and the following data were obtained. During aerobic cellular respiration, oxygen gas is consumed at the same rate as carbon dioxide gas is produced. In order to provide accurate volumetric measurements of oxygen gas consumption, the experimental setup should include which of the following?

A. A substance that removes carbon dioxide gas B.A plant to produce oxygen C.A glucose reserve D.A valve to release excess water A

A researcher claims that the synthesis of ATP from ADP and inorganic phosphate (Pi) is essential to cellular function. Which of the following statements best helps justify the researcher's claim?

A. ADP is a small molecule that some cells release into their environment as a way of communicating with other cells. B. ATP hydrolysis is an energy-releasing reaction that is often coupled with reactions that require an input of energy. C. Inorganic phosphate (Pi) is a substance that cells typically acquire from their environment. D. ATP synthase is a mitochondrial enzyme that catalyzes the conversion of ADP and Pi to ATP. B

Anabolism is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy. The synthesis of protein or carbohydrate polymers always produces which of the following as a byproduct of these synthesis reactions?

A. ATP B. Carbon dioxide C. Urea D. Water D

Experimental evidence shows that the process of glycolysis is present and virtually identical in organisms from all three domains, Archaea, Bacteria, and Eukarya. Which of the following hypotheses could be best supported by this evidence?

A. All organisms carry out glycolysis in mitochondria B. Glycolysis is a universal energy-releasing process and therefore suggests a common ancestor for all forms of life. C. Across the three domains, all organisms depend solely on the process of anaerobic respiration for ATP production D. The presence of glycolysis as an energy-releasing process is all organisms suggest that convergent evolution occurred. B

The figures below illustrate the similarities between ATP synthesis in mitochondria and chloroplasts. The figures can best assist in answering which of the following questions?

A. Do electron transport chains create a gradient so that ATP synthase can generate ATP molecules? B. What are the sources of energy that drive mitochondrial and chloroplast electron transport systems? C. What is the optimal temperature at which ATP synthase chemically converts ADP and a phosphate group into one molecule of ATP? D. What is the evolutionary relationship between the ATP synthase in mitochondria and the ATP synthase in chloroplast? A

Which of the following statements most directly supports the claim that different species of organisms use different metabolic strategies to meet their energy requirements for growth, reproduction, and homeostasis?

A. During cold periods pond-dwelling animals can increase the number of unsaturated fatty acids in their cell membranes while some plants make antifreeze proteins to prevent ice crystal formation in tissues. B. Bacteria lack introns while many eukaryotic genes contain many of these intervening sequences. C. Carnivores have more teeth that are specialized for ripping food while herbivores have more teeth that are specialized for grinding food. D. Plants generally use starch molecules for storage while animals use glycogen and fats for storage. D

Many different fermentation pathways occur in different organisms in nature. For example, skeletal muscle cells convert pyruvate into lactic acid when no oxygen is present. Yeast cells can produce alcohol and carbon dioxide under the same circumstances. However, regardless of the specific reactions, the purpose of glycolysis is an important one. Which statement best describes the importance of glycolysis?

A. It produces large amounts of ATP by substrate level phosphorylation. B. It reoxidizes NADH so that glycolysis can continue. C. It produces pyruvate, which is the raw material for oxidative phosphorylation. D. It occurs in the cytoplasm. D

If ATP breakdown (hydrolysis) is inhibited, which of the following types of movement across cell membranes is also inhibited

A. Movement of oxygen into a cell B. Movement of water through aquaporins C. Passage of a solute against its concentration gradient D. Facilitated diffusion of a permeable substance C

A student used a microscope to observe a wet-mount slide of red onion epidermal cells that were suspended in a 1% NaCl solution. The student then added a 15% NaCL solution to the slide and observed the changes that occurred. The student's observations are represented in Figure 1. Which of the following most directly explains the changes in the cells?

A. The degradation of DNA in the nuclei of the cells B. The lysis of chloroplasts in the cells C. The movement of water from the central vacuoles of the cells into the solution D. The movement of NaCl from the solution into the cytoplasm of the cells. C

A human kidney filters about 200 liters of blood each day. Approximately two liters of liquid and nutrient waste are excreted as urine. The remaining fluid and dissolved substances are reabsorbed and continue to circulate throughout the body. Antidiuretic hormone (ADH) is secreted in response to reduced plasma volume. ADH targets the collecting ducts in the kidney, stimulating the insertion of aquaporins into their plasma membranes and an increased reabsorption of water. If ADH secretion is inhibited, which of the following would initially result?

A. The number of aquaporins would increase in response to the inhibition of ADH B. The person would decrease oral water intake to compensate for the inhibition of ADH. C .Blood filtration would increase to compensate for the lack of aquaporins. D. The person would produce greater amounts of dilute urine. D

Which of the following best describes the function of the coenzymes NAD+ and FAD in eukaryotic cellular respiration?

A. They participate directly in the phosphorylation of ADP to ATP. B. They serve as final electron acceptors in the electron transport chain. C. They aid vitamins such as niacin in the breakdown of glucose. D. They accept electrons during oxidation-reduction reactions.

To investigate bacterial metabolism, a researcher divided a population (culture) of Staphylococcus capitis bacteria into two sets of culture tubes containing glucose. The researcher added a chemical to one set of tubes and measured the pH of the cultures at 5 -minute intervals as the bacteria metabolized the glucose into lactic acid. The data are shown in Table 1. Which of the following was the dependent variable in the researcher's experiment?

A. Time B. pH C. Glucose concentration D. Lactic acid concentration B

Amylase is an enzyme found in the saliva of animals. It begins the initial breakdown of organic molecules. Which of the following would be useful as a substrate to measure the activity of amylase in a kola bear?

A. cellulose B.Starch C.Glucose D.An Amino Acid B

An experiment to measure the rate of respiration in crickets and mice at 10 degree C and 25 degree C was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O^2 consumed per gram of organism over several five-minute trials and the following data were obtained. According to the data, the crickets at 25 degree C have greater oxygen consumption per gram of tissue than do the crickets at 10 degree C. This trend in oxygen consumption is the opposite of that in the mice. The difference in trends in oxygen consumption among crickets and mice is due to their.

A. relative size B. mode of nutrition C. mode of internal temperature regulation D. mode of ATP production C

Researchers applied radioactive phosphorus and radioactive calcium to a freshly cut tree stump. Eight days later, they came back to measure the distribution of the radioisotopes. They found that nineteen different species of shrubs and trees within a seven-meter radius had taken up the radioactive elements. No radioactivity was detected in the air. Radioactive isotopes were never detected in any samples containing just soil taken during the experiment. The findings implies that the

A. soil does not provide the ecosystem with minerals B. isotopes were undetectable in very small amount C. isotopes were transported via vascular tissues D. plants quickly return minerals to the soil in which they grow. C

Evaluate the following statements: Oxygen is NOT a greenhouse gas; therefore, gases containing oxygen, such as ozone, nitrous oxide, and carbon dioxide are NOT greenhouse gases either.

A.True. It is impossible for a gas containing oxygen to be greenhouse gas. B.True. Compounds display emergent properties that are very similar to the elements that form them. C.False. Compounds can have emergent properties that are very different from the elements that form them. D.False. Oxygen is a special case because of its reactivity and electromagnetically C

The active site between enzymes allow for specific substrate to bind. A substrate may bind to the active site of an enzyme in a variety of ways. Which of the following is NOT a valid mechanism for substrate-enzyme building?

A.hydrogen bonds B.peptide bonds C.ionic bonds D.van der Waals interactions B

If the M checkpoint is not cleared, what stage of mitosis will be blocked?

Anaphase

Select the one heading to which it is most closely related. Each heading may be used once, more than once, or not at all. (A) Glysolysis (B) Krebs cycle (citric acid cycle) (C) Calvin cycle (light-independent reactions of photosynthesis) (D) Chemiosmosis Process in which CO2, is released as a by-product of oxidation-reduction reactions

B. Krebs cycle(citric acid cycle)

At which of the cell cycle checkpoints do external forces have the greatest influence?

G1

Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. His results are posted below: Why would the bacteria congregate around the different areas of the algae?

The algae produce the most oxygen in the areas where they absorbed the most light for photosynthesis.

You notice that a plant that grows near drain that empties your air conditioner's condensate water grows faster than the other plants in your yard. What would be a plausible explanation for the plant's growth rate?

The excess water provides electrons for the light dependent reactions

The data shown above were collected from a eukaryotic cellular culture grown at a constant temperature of 37o C in a buffered environment. From what part of the cell and during which event were the samples most likely obtained?

Trial 1 took place in the mitochondrial matrix during the citric acid cycle

A popular diet is to lower your intake of sugars and force your body to digest proteins instead. Examine the diagram at the left. What is one reason why eating more proteins may cause you to lose weight?

Unlike fats and carbohydrates, energy cannot be extracted from proteins until the end of glycolysis

What is the main prerequisite for clearance at the G2 checkpoint?

accurate and complete DNA replication

Many of the negative regulator proteins of the cell cycle were discovered in what type of cells?

cancer cells

Which negative regulatory molecule can trigger cell suicide (apoptosis) if vital cell cycle events do not occur?

p53

In an experiment, a yeast culture was given a 10% glucose solution as a food source. The glucose used to make the solution contained a small amount of the radioactive isotope of carbon, Carbon-14. The yeast was kept in a sealed test tube under anaerobic conditions. After 30 minutes, which of the following substances would contain the radioactive carbon isotope?

the pyruvate inside each yeast cell