ap bio midterm mcq questions

A student designs an experiment to investigate the influence of temperature on enzyme function. The student's plan is presented in Table 1. Which test tubes are controls in the experiment?

c) Test tubes 1, 3, 5, and 7

Which of the following best describes the numbered areas?

a) Areas 1 and 3 are polar, since the membrane molecules are aligned with water molecules.

All eukaryotic cells contain at least one Golgi complex, typically located in the cytoplasm and near the endoplasmic reticulum. Which of the following best describes a process that occurs within the Golgi complex?

a) Enzymatic modification of newly synthesized integral membrane proteins

The active transport pump used to move sodium ions across the membranes of gill cells in a freshwater fish has each of the following characteristics EXCEPT:

a) It uses osmosis to carry sodium ions into the cells.

Figure 1 represents a nucleic acid fragment that is made up of four nucleotides linked together in a chain.

b) The identity of each nitrogenous base

Figure 1 represents a common process that occurs in organisms. Figure 1. Structural formula for a common biological reaction. Which of the following is an accurate description of the process shown in Figure 1 ?

d) The formation of a covalent peptide bond in a dehydration synthesis reaction

All of the following cell components are found in prokaryotic cells EXCEPT

d) nuclear envelope

Researchers investigated the effect of urea on the three-dimensional structure of a certain enzyme. The researchers dissolved the enzyme in an aqueous buffer solution and added urea to the solution. The enzyme did not appear to have a secondary or tertiary structure. The researchers carefully removed the urea from the solution and determined that the enzyme had the original secondary and tertiary structure again. Based on the results of the experiment, which of the following statements best predicts the effect of urea on the enzyme's function?

a) Function will be disrupted by adding the urea and regained by removing the urea.

A researcher designs an experiment to investigate whether soil bacteria trigger the synthesis of defense enzymes in plant roots. The design of the experiment is presented in Table 1. For each group in the experiment, the researcher will determine the average rate of change in the amount of defense enzymes in the roots of the seedlings. Which of the following statements best helps justify the inclusion of group 2 as one of the controls in the experiment?

a) It will show whether the changes observed in group 1 depend on the metabolic activity of soil bacteria.

Researchers investigated the influence of environmental pH on the activity of peroxidase, an enzyme that catalyzes the conversion of hydrogen peroxide to water and oxygen gas. In an experiment, the researchers added a hydrogen peroxide solution containing guaiacol to several identical test tubes and adjusted the solution in each test tube to a different pH. The researchers included the guaiacol because it caused the solutions to change color as the reactions proceeded, which the researchers relied on for measuring reaction rates. Finally, the researchers added the same amount of peroxidase to each test tube and measured the rate of each reaction at 23°C. The results of the experiment are represented in Figure 1. Based on Figure 1, which of the following statements best predicts the effect that a change from a moderately acidic environment (pHpH near 6) to a basic environment will have on peroxidase activity?

a) Peroxidase activity will decrease.

A student calculated the average surface area-to-volume ratio of four different types of human epithelial cells. The results are shown in the table below. Based on the data, which type of cell would be best suited for the lining the alveoli of the lungs, where diffusion of carbon dioxide and oxygen must occur very rapidly?

a) Simple squamous cells

Acetylcholinesterase (AChE)(AChE) is a protein that catalyzes the conversion of acetylcholine to acetate and choline. When the concentration of AChEAChE in an aqueous solution is held constant, the rate of the reaction catalyzed by AChEAChE increases with increasing concentrations of substrate. At low concentrations of acetylcholine, a small increase in the substrate concentration results in a large increase in the reaction rate. At high concentrations of acetylcholine, however, a large increase in the substrate concentration results in only a small increase in the reaction rate. Which of the following statements correctly explains the observed effect of the acetylcholine concentration on the rate of the enzyme-catalyzed reaction?

a) The active site of AChEAChE is specific for acetylcholine, and only one substrate molecule can occupy the active site at a time.

In an experiment, the efficiency of oxygen exchange across the plasma membrane is being assessed in four artificial red blood cells. The table above lists some properties of those artificial cells. Other conditions being equal, which artificial cell is predicted to be the most efficient in exchanging oxygen with the environment by diffusion?

a) The cuboidal cell

Muscle cells have high ATPATP demands. Which of the following is a scientific claim about how the structure of the mitochondria in muscle cells should be different than it is in other cells because of the high energy demands of mitochondria?

a) The inner membrane of the mitochondria in muscle cells should have more folds to increase the surface area, allowing more ATPATP to be synthesized.

European flycatchers feed caterpillars to their hatchlings. Graph 1 shows the average dates of hatching and fledging (leaving the nest), and the biomass of the caterpillars between early May (when flycatcher young hatch) and June (when fledging of young occurs). Graph 1. Comparison of European flycatcher hatching and fledging dates and caterpillar biomass Based on the data, scientists claim that the reproductive behavior of European flycatchers is influenced by the availability of energy sources. Which of the following statements best justifies this claim?

a) Young European flycatchers hatch from eggs when caterpillar biomass is available for the young birds to consume and convert into energy for growth.

When a substance moves across the plasma membrane along a concentration gradient at a rate faster than would be expected by simple diffusion alone but without the expenditure of metabolic energy, the process is best described as

a) facilitated diffusion

a small protein is composed of 110 amino acids linked together in a chain. as shown in figure 1 the first and last five amino acids in the chain are hydrophobic (have nonpolar and uncharged R-groups), whereas the remaining 100 amino acids are hydrophilic (have charged or polar R- groups). the nature of the R- group determines if the amino acid is hydrophobic or hydrophilic. a mutation results in the production of a version of the small protein that is only 105 amino acids long, as shown in figure 2. five of the hydrophobic amino acids are missing from one end of the change. describe how the mutation would change the tertiary structure of the protein. be specific.

a) globular shape because tertiary structure

Catalase is an enzyme found in yeast cells that facilitates the chemical breakdown of hydrogen peroxide to water and oxygen gas. An experiment was conducted to determine the effect of pHpH on catalase function. Five buffer solutions of varying pHpH (2, 4, 6, 8, and 10) were prepared and added to separate test tubes. Hydrogen peroxide (H2O2)(H2O2) was added to each test tube. Yeast was added, and the reactions were timed. After 1 minute the amount of oxygen gas released was determined by measuring the foam layer produced in each test tube. Figure 1 illustrates the experimental setup. A set of five additional test tubes were prepared and used as controls. Which of the following best describes the contents expected to be contained in one of the five control test tubes?

a) pHpH 4 buffer solution and hydrogen peroxide only

A researcher claims that a certain herbicide suppresses plant growth by inhibiting chloroplast function. To test the claim, the researcher treats isolated chloroplasts with increasing concentrations of the herbicide. The data from the experiment are presented in Table 1. Which of the following statements best clarifies how the data support the researcher's claim?

b) ATPATP synthase activity depends on a proton gradient across the thylakoid membrane.

The following questions refer to the following diagram. For each phrase or sentence, select the labeled part to which it is most closely related. Each option may be used once, more than once, or not at all for each group.

b) B (chloroplasts)

Plant cell walls are composed of cellulose, while fungal cell walls are composed of chitin. A group of scientists hypothesize that this difference means the cell wall has largely different functions in plant cells and fungal cells. Alternatively, another group of scientists hypothesize that despite their biochemical differences, plant and fungal cell walls serve similar functions. Which of the following observations would best support the alternative hypothesis described above?

b) In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane.

Which of the following statements best explains the processes of passive and active transport?

b) Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy.

Which of the following statements best describes how organisms such as rabbits obtain the carbon necessary for building biological molecules?

b) Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they rearrange into new carbon-containing molecules.

In an experiment, a researcher prepares a reaction mixture by dissolving a substance in a buffered solution. The substance is the substrate of a certain enzyme. The researcher adds a small amount of the enzyme to the reaction mixture and measures the amount of product that is formed over time. The data are represented in Figure 1. Which of the following best predicts the immediate result of adding more substrate to the reaction mixture at the point indicated by the arrow in Figure 1?

b) The amount of product will decrease until the reaction reaches its equilibrium point or until the enzyme is been used up by the reaction.

DNA and RNA are nucleic acids that can store biological information based on the sequence of their nucleotide monomers. Figure 1 shows a short segment of each of the two types of nucleic acids. Which of the following best describes a structural difference between DNA and RNA?

b) The backbone of DNA contains deoxyribose, whereas the backbone of RNA contains ribose.

Researchers compared similar proteins from related organisms in different habitats. They found that the proteins from organisms living in harsh environments had a greater number of cysteine amino acids than did proteins from organisms not living in harsh environments. The structure of cysteine is shown. Bonds can form between the sulfur atom of different cysteine amino acids (S-S bonds).

b) The change leads to increased protein stability because of an increased number of S-S bonds in the tertiary structure of the proteins.

Which of the following best describes how amino acids affect the tertiary structure of a protein?

b) The interactions of the different R-groups with other R-groups and with their environment determine the tertiary structure of the protein.

Water and ammonia interact to form hydrogen bonds, as represented in the figure.Which statement best helps explain the formation of the hydrogen bond represented in the figure?

b) The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.

The following questions refer to an experiment in which a dialysis-tubing bag is filled with a mixture of 3% starch and 3% glucose and placed in a beaker of distilled water, as shown below. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot. From the initial conditions and results described, which of the following is a logical conclusion?

b) The pores of the bag are larger than the glucose molecules but smaller than the starch molecules.

Brown fat is a type of fat tissue found in hibernating mammals. Inside the mitochondria of these fat tissue cells, these mammals have an uncoupling protein embedded in the inner mitochondrial membrane. This uncoupling protein allows hydrogen ions to leak from the intermembrane space back into the mitochondrial matrix. Figure 1 shows details of the processes in the inner mitochondrial membrane. Figure 1. Processes in the inner mitochondrial membrane Which of the following statements provides reasoning that supports the claim that brown fatty tissue keeps an animal warm?

b) The uncoupling protein in this tissue reduces the proton gradient across the membrane and thus produces heat to warm the animal without ATPATP production.

Which of the following best describes the structures of carbohydrates?

b) They occur as monomers, chains of monomers, and branched structures.

The figure below illustrates a eukaryotic cell. Which of the following best describes how the three structures indicated by the arrows work together? (rough ER, golgi apparatus, vesicles)

b) To synthesize and isolate proteins for secretion or for use in the cell

Liver cells manufacture glycoproteins, while adipose cells store fat. Which of the following subcellular structures is likely to be more prominent in liver cells than in adipose cells?

b) golgi apparatus

A researcher claims that spinach leaves capture the most energy from light waves in the range of 500 nmnm to 600 nmnm. To test the claim, the researcher will place spinach leaves in separate chambers and expose the leaves to different wavelengths of light. For each chamber, the researcher will measure the amount of oxygen gas (O2)(O2) that is produced in one hour. Which of the following graphs best represents data from the experiment that will support the researcher's claim?

b) positive left to right, straight horizon line, down left to right (looks like table /-\)

Which of the following components of the cell membrane is responsible for active transport?

b) protein

Which of the following best describes the formation of the bond shown in Figure 1 ?

c) A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2O .

Aminolevulinate dehydratase (ALADALAD) is an enzyme that relies on zinc as a cofactor. A zinc ion binds to the ALADALAD active site, where it forms favorable interactions with the side chains of three amino acids. Researchers have found that substituting a lead ion for a zinc ion in the ALADALAD active site causes inhibition of ALADALAD. Which of the following statements best helps explain how the lead ion causes inhibition of ALAD?

c) It changes the three-dimensional structure of the active site so that ALADALAD is no longer compatible with its substrate.

Pectinase is a protein that catalyzes the breakdown of pectic polysaccharides in plant cell walls. A researcher designs an experiment to investigate the effect of salinity on the ability of pectinase to lower the activation energy of the reaction involved. The design of the experiment is presented in Table 1. For each test tube, the researcher will measure the amount of product formed over 20 minutes. Which of the following statements best helps justify the inclusion of test tube 5 in the experiment?

c) It will act as a control for test tube 6 by showing the effect of the presence or absence of the enzyme.

The molecular structures of linoleic acid and palmitic acid, two naturally occurring substances, are shown in the figure. Based on the molecular structures shown in the figure, which molecule is likely to be solid at room temperature?

c) Palmitic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together.

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

c) Passage of a solute against its concentration gradient

The carbohydrates glucose, galactose, and fructose have the same chemical formula (C6H12O6) but different structural formulas, as represented in the figure.Which of the following statements about glucose, galactose, and fructose is most likely true?

c) The carbohydrates have different properties because they have different arrangements of carbon, hydrogen, and oxygen atoms.

Intravenous (IV) solutions administered to patients are normally isotonic. Which of the following is most likely if an IV of distilled water is administered to a patient?

c) The cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood.

Researchers investigated the influence of environmental pHpH on the activity of peroxidase, an enzyme that catalyzes the conversion of hydrogen peroxide to water and oxygen gas. In an experiment, the researchers added a hydrogen peroxide solution containing guaiacol to several identical test tubes and adjusted the solution in each test tube to a different pHpH. The researchers included the guaiacol because it caused the solutions to change color as the reactions proceeded, which the researchers relied on for measuring reaction rates. Finally, the researchers added the same amount of peroxidase to each test tube and measured the rate of each reaction at 23°C23°C. The results of the experiment are represented in Figure 1. One of the researchers proposes using oxygen gas production to measure reaction rates. Which of the following statements best justifies the use of the proposed modification as a way of creating an appropriate control for the investigation?

c) The experiment can be repeated without guaiacol, which will reveal the effect of guaiacol on the reaction rates.

The diagram above represents a typical rod-shaped bacterium. Which of the following best describes a feature shown in the diagram that is unique to archaea and bacteria?

c) The organism does not have a nuclear membrane surrounding its genetic material.

Students conducted a controlled experiment to investigate whether sawdust provides enough nutrients to support plant growth. The students separated ten nearly identical sunflower seedlings into two groups. They grew the seedlings in the first group in potting soil and the seedlings in the second group in sawdust composed mostly of cellulose. After twenty days, the students recorded observations about the seedlings in each group. The students' observations are presented in the table.The observed differences between the groups most likely resulted from differences in the ability of the seedlings to produce which of the following monomers?

c) These structures are the only ones that depict protein and nucleic acid

A sample of human blood was placed in a test tube containing a physiological saline solution (0.9% sodium chloride). This type of solution is often used intravenously to quickly rehydrate patients. A drop of the blood from the test tube was placed on a slide and red blood cells (RBCs) were observed under a microscope. Three possible outcomes are diagrammed below. Which of the following best predicts which diagrammed microscope view the laboratory worker would see and best explains why?

c) View 2 because the rate of water movement into the RBCs equals the rate of water movement out of the cells

Which of the following scientific questions is most relevant to the model represented in the figure above?

c) Which molecular substance is actively transported across the plasma membrane?

A researcher claims that budding yeast are able to survive in different environments because they produce enzymes that allow them to use different molecules as sources of matter and energy. Which of the following statements best helps justify the researcher's claim by providing a relevant example?

c) Yeast cells produce invertase, which is an enzyme that catalyzes the conversion of the disaccharide sucrose into glucose and fructose.

Researchers claimed that a particular organelle originated from a free-living prokaryotic cell that was engulfed by a larger cell, as shown in Figure 1. Figure 1. A model showing a cell engulfing a smaller cell Which of the following provides evidence to best support the researchers' claim?

c) the organelle has a double membrane

A researcher proposes a model to explain how enzyme-substrate interactions determine enzyme specificity. The model is based on the idea that substrate molecules form favorable interactions with the amino acid side chains in an enzyme's active site. Based on the model, which of the following statements best explains an enzyme's specificity for a particular substrate molecule?

d) A molecule with negative charges interacts with positively charged side chains in the enzyme's active site.

A researcher claims that the initial rise of oxygen in Earth's early atmosphere, which occurred approximately 2.3 billion years ago, resulted from the metabolic activity of prokaryotic organisms. The claim is based on an interpretation of the geochemical and fossil evidence represented in Figure 1. Figure 1. Selected events in geologic time based on geochemical and fossil evidence Which of the following types of evidence will best support the researcher's claim?

d) Evidence that the cyanobacteria produced oxygen as a by-product of photosynthesis

Figure 1 is a diagram of water molecules at the air-water interface at the surface of a pond.Based on Figure 1, which of the following best describes how the properties of water at an air-water interface enable an insect to walk on the water's surface?

d) Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

Polypeptides are continuously being formed and degraded. One of these processes is shown.

d) It represents a polypeptide chain that is broken down through a hydrolysis reaction.

The CFTR protein is made up of 1,480 amino acids linked together in a chain. Some humans produce a version of the CFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of the amino acid chain.Which of the following best predicts how the amino acid deletion will affect the structure of the CFTR protein?

d) It will affect the primary, secondary, and tertiary structures of the CFTR protein

Changing the shape or morphology of the mitochondrial inner membrane can change the efficiency of mitochondrial function. Which of the following outcomes will most likely result from a change in the shape of the mitochondrial inner membrane from a highly folded surface to a smooth, flat surface?

d) Mitochondria will become less efficient because the surface area of the inner mitochondrial membranes will decrease.

The manner in which several different ions and molecules move through a cell membrane is shown in the diagram above. For each ion or molecule, the relative concentration on each side of the membrane is indicated. Which of the following accurately describes one of the movements taking place?

d) Na+ transport out of the cell requires ATP hydrolysis.

Which of the following conclusions is most clearly supported by the representations of nucleic acid #1 and nucleic acid #2 ?

d) Nucleic acid #1 contains adenine-thymine base pairs, whereas nucleic acid #2 does not.

Researchers investigated the influence of environmental pHpH on the activity of peroxidase, an enzyme that catalyzes the conversion of hydrogen peroxide to water and oxygen gas. In an experiment, the researchers added a hydrogen peroxide solution containing guaiacol to several identical test tubes and adjusted the solution in each test tube to a different pHpH. The researchers included the guaiacol because it caused the solutions to change color as the reactions proceeded, which the researchers relied on for measuring reaction rates. Finally, the researchers added the same amount of peroxidase to each test tube and measured the rate of each reaction at 23°C23°C. The results of the experiment are represented in Figure 1. Which of the following actions will provide a negative control for the investigation?

d) Repeating the experiment using heat-denatured peroxidase

A researcher claims that genetic variation provides organisms with the ability to survive and reproduce in different environments. To support the claim, the researcher makes the following observation: bacteria that contain plasmids (small DNADNA molecules) are resistant to a wider range of antibiotics than are bacteria that contain no plasmids. Which of the following statements best establishes a connection between the observation and the researcher's claim?

d) Some plasmids contain antibiotic resistance genes.

Phycobiliproteins are a complex of accessory pigments and proteins found in cyanobacteria but not in green algae. A researcher claims that the phycobiliprotein pigments in cyanobacteria allow the cyanobacteria to survive in certain aquatic niches better than green algae can. Which of the following statements best justifies the researcher's claim?

d) The additional pigments absorb light at wavelengths that green algae cannot absorb; this may allow cyanobacteria to capture more light energy for photosynthesis than green algae can in certain areas.

The figure shows a model of the exchange of matter between the organisms that live together in an aquarium. The model includes matter exchange between plants, fish, and bacteria. The bacteria are represented as rod-shaped organisms living in the gravel at the bottom of the aquarium. Which of the following statements best describes how molecules released by the fish become nutrients for the plants?

d) The ammonia molecules released by the fish are converted by the bacteria to nitrates, which are used by the plants to make proteins and nucleic acids.

A researcher claims that the incorporation of carbon dioxide into organic molecules during photosynthesis does not violate the second law of thermodynamics. Which of the following statements best helps justify the researcher's claim?

d) The total system that includes photosynthetic organisms and the Sun becomes less ordered over time.

Dialysis tubing is permeable to water molecules but not to sucrose. Four dialysis tubes are half filled with 5 percent, 10 percent, 20 percent, and 40 percent sucrose solutions, respectively, and two dialysis tubes are half filled with distilled water. The dialysis tubes are all sealed at both ends, and the initial masses are determined. Five dialysis tubes are placed into beakers containing distilled water, and the sixth dialysis tube, containing distilled water, is placed into a 40 percent sucrose solution. The masses of the dialysis tubes are recorded at 30-minute intervals for 90 minutes, as shown in the table below. The contents of which dialysis tube are initially isotonic to the distilled water in the beaker?

e) 5 (all equal - isotonic)

Which of the following describes the most likely location of cholesterol in an animal cell?

a) Embedded in the plasma membrane