a cell from heart muscle would more than likely contain an unusually high proportion of

HESI A2

Biology HESI A2 Practice Test

1. A cell from heart muscle would more than likely contain an unusually high proportion of which of the following?

A. lysosomes
B. mitochondria
C. mRNA
D. ribosomes

Correct answer: B

Rationale: A cell from heart muscle would more than likely contain an unusually high proportion of mitochondria because the heart muscle requires a significant amount of energy to function properly. Mitochondria are the powerhouse of the cell and are responsible for producing energy in the form of ATP through cellular respiration. Therefore, to meet the high energy demands of the heart muscle, it would need a higher concentration of mitochondria compared to other cell types. Choices A, C, and D are incorrect because while lysosomes, mRNA, and ribosomes are essential components of a cell, they do not play as direct a role in meeting the high energy demands of heart muscle as mitochondria do.

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 term for the breakdown of glycogen into glucose subunits?

A. Hydrolysis
B. Reduction
C. Metabolism
D. Transpiration

Correct answer: A

Rationale: Hydrolysis is the term used to describe the breakdown of large molecules into smaller units by adding water. In the case of glycogen being broken down into glucose subunits, this process involves the addition of water molecules to break the glycosidic bonds between glucose molecules, resulting in the release of individual glucose subunits. This process is crucial for providing cells with a source of energy when needed. Choice B, Reduction, refers to a chemical reaction involving a gain of electrons or a decrease in oxidation state, not the breakdown of glycogen into glucose subunits. Choice C, Metabolism, is a broad term encompassing all biochemical processes in an organism, including anabolism and catabolism, but does not specifically describe the breakdown of glycogen into glucose subunits. Choice D, Transpiration, is the process of water movement through a plant and is not related to the breakdown of glycogen into glucose subunits.

4. Why doesn't an antibiotic work for treating the flu?

A. The antibiotic is for a different type of infection
B. The antibiotic is not effective against viruses
C. The antibiotic is not prescribed in a high enough dosage
D. None of the above

Correct answer: B

Rationale: The correct answer is B. Antibiotics are used to treat bacterial infections, not viral infections like the flu. The flu is caused by a virus, and antibiotics are ineffective against viruses. Choice A is incorrect because it does not address the fact that antibiotics do not work on viruses. Choice C is incorrect as the issue is not related to the dosage amount, but rather the nature of the infection. Choice D is incorrect as there is a specific reason why antibiotics do not work for the flu.

5. Which of the following is true of optical microscopy?

A. Utilizes scanning electrons
B. Utilizes visible light
C. Utilizes dye for samples
D. More than one of the above is true

Correct answer: D

Rationale: The correct answer is D, 'More than one of the above is true.' Optical microscopy utilizes visible light (Choice B) and often involves the use of dyes for samples (Choice C). Using dyes helps enhance contrast, making it easier to visualize the structures being observed. Choice A is incorrect as optical microscopy does not utilize scanning electrons, but rather visible light.