a cell is in a solution in which the concentration of solutes is higher inside the cell than outside the cell what would you expect to happen to the c

HESI A2

Biology HESI A2 2024

1. A cell is in a solution in which the concentration of solutes is higher inside the cell than outside the cell. What would you expect to happen to the cell?

A. It will swell and possibly burst.
B. It will shrivel and shrink.
C. It will maintain its current size.
D. It will grow a supportive cell wall.

Correct answer: A

Rationale: When a cell is in a solution where the concentration of solutes is higher inside the cell than outside, it is in a hypertonic environment. In this situation, water will move into the cell in an attempt to equalize the concentration of solutes on both sides of the cell membrane through the process of osmosis. As a result, the cell will swell as it takes in more water, potentially leading to bursting or cell lysis. Choice B is incorrect because a cell in a hypertonic solution will not shrivel and shrink due to water moving into the cell. Choice C is incorrect because the cell will not maintain its current size; it will swell. Choice D is incorrect because growing a supportive cell wall is not the immediate response to being in a hypertonic environment.

2. What happens to glucose during glycolysis?

A. Its energy is entirely lost.
B. It splits into molecules of pyruvic acid.
C. It is stored in NADH.
D. It joins with molecules of citric acid.

Correct answer: B

Rationale: During glycolysis, glucose undergoes a series of enzymatic reactions in the cytoplasm of the cell, resulting in its breakdown into two molecules of pyruvic acid. This process also generates ATP and NADH as energy carriers. Choice A is incorrect because glucose is not entirely lost, but rather converted into other molecules. Choice C is incorrect because NADH is a product of glycolysis, not a storage form for glucose. Choice D is incorrect as glucose does not join with molecules of citric acid during glycolysis, but rather in subsequent stages of cellular respiration.

3. What is the role of ribosomes in the cell?

A. Break down cellular waste
B. Organize cellular division
C. Synthesize proteins
D. Provide cellular structure

Correct answer: C

Rationale: The correct answer is C: Synthesize proteins. Ribosomes are responsible for protein synthesis by linking amino acids together. Choice A is incorrect because ribosomes do not break down cellular waste. Choice B is incorrect as ribosomes do not organize cellular division. Choice D is incorrect because ribosomes do not provide cellular structure.

4. How should a researcher test the hypothesis that eating chocolate leads to acne in teenagers?

A. Take 100 teenagers and feed each one a different amount of chocolate daily for 60 days; then test for acne.
B. Take 100 teenagers and feed 50 two bars of chocolate daily for 60 days while the other 50 eat no chocolate; then test for acne.
C. Take 1 teenager and feed him or her two bars of chocolate for 30 days and no chocolate for 30 days; then test for acne.
D. Take 100 teenagers and feed them no chocolate for 30 days and two bars of chocolate apiece for 30 days; then test for acne.

Correct answer: B

Rationale: Option B is the correct approach to test the hypothesis that eating chocolate leads to acne in teenagers. This method involves having a control group (50 teenagers not consuming chocolate) and an experimental group (50 teenagers consuming two bars of chocolate daily), which allows for comparison. By having two distinct groups, researchers can assess the impact of chocolate consumption on acne development. Option A lacks a control group for comparison, making it harder to attribute any observed effects specifically to chocolate consumption. Option C only involves a single subject, which limits the generalizability of the results. Option D, where all teenagers experience both conditions, does not allow for a direct comparison between chocolate consumption and acne development, as all subjects are exposed to both conditions.

5. How many different types of nucleotides are there in DNA?

A. one
B. two
C. four
D. eight

Correct answer: C

Rationale: The correct answer is 'C: four.' DNA is composed of four different types of nucleotides: adenine, thymine, guanine, and cytosine. These nucleotides pair up in specific combinations to form the genetic code. Choices 'A: one,' 'B: two,' and 'D: eight' are incorrect because DNA consists of a set of four distinct nucleotides, not one, two, or eight.