which structure is responsible for organizing protein synthesis

HESI A2

HESI A2 Practice Test Biology

1. Which organelle is responsible for organizing protein synthesis?

A. Nucleus
B. Ribosome
C. Lysosome
D. Vacuole

Correct answer: B

Rationale: The correct answer is B: Ribosome. Ribosomes are responsible for organizing protein synthesis by assembling amino acids. They are the cellular machinery where proteins are synthesized. The other choices, such as the nucleus, lysosome, and vacuole, do not directly participate in protein synthesis. The nucleus contains DNA and controls cell activities, the lysosome is involved in digestion and waste removal, and the vacuole is responsible for storage and maintaining cell turgor pressure.

2. What happens during the S phase of the cell cycle?

A. Chromosomes are duplicated.
B. Cell growth occurs.
C. DNA is synthesized.
D. DNA is destroyed.

Correct answer: A

Rationale: During the S phase of the cell cycle, chromosomes are duplicated. This is a critical step in cell division as each chromosome is replicated to ensure that the resulting daughter cells receive an identical set of genetic information. Choices B, C, and D are incorrect because cell growth primarily occurs in the G1 phase, DNA synthesis happens during the S phase, and DNA destruction does not occur during any phase of the cell cycle.

3. How should a researcher test the hypothesis that radiation from cell phones is significant enough to raise the temperature of water in a test tube?

A. Dial a cell phone that rests beside a test tube of water, let it ring for two minutes, and record the temperature of the water before and after the two-minute interval.
B. Dial a cell phone that rests beside a test tube of water; let it ring for two, three, and four minutes; and record the temperature of the water before and after each interval.
C. Use three different brands of cell phone; dial each as it rests beside its own test tube of water, let it ring for two minutes, and record the temperature of the water before and after the two-minute interval.
D. Use three different brands of cell phone, dial each and let one ring for two minutes, one for three minutes, and one for four minutes; record the temperature of the water before and after each interval.

Correct answer: A

Rationale: To test the hypothesis that radiation from cell phones raises the temperature of water in a test tube, the most appropriate method is to dial a cell phone next to a test tube of water, let it ring for a consistent two-minute interval, and record the temperature before and after. Choice A is correct because it provides a controlled approach to isolate the impact of the phone's radiation on the water temperature. Choices B, C, and D introduce additional variables that could confound the results. Choice B varies the duration of exposure, making it difficult to attribute temperature changes specifically to the radiation. Choice C introduces the factor of different cell phone brands, which could introduce variability not related to radiation. Choice D also varies exposure times and introduces the factor of multiple phone brands, making it harder to determine the direct impact of cell phone radiation on water temperature. Therefore, choice A is the most suitable option for this experiment.

4. A cell containing 12 chromosomes divides into daughter cells in mitosis. How many chromosomes are in each daughter cell?

A. 3
B. 6
C. 12
D. 24

Correct answer: C

Rationale: During mitosis, the cell undergoes nuclear division without changing the number of chromosomes. Therefore, the daughter cells produced will have the same number of chromosomes as the parent cell. In this case, since the parent cell contains 12 chromosomes, each daughter cell will also have 12 chromosomes. Choices A, B, and D are incorrect because during mitosis, the chromosome number remains the same, and daughter cells inherit the same number of chromosomes as the parent cell.

5. What is the classification of organisms into different categories based on their physical characteristics and presumed natural relationship?

A. Biology
B. Taxonomy
C. Grouping
D. Nomenclature

Correct answer: B

Rationale: Taxonomy is the correct answer. Taxonomy is the branch of biology that deals with the classification of organisms into different categories based on their physical characteristics and presumed natural relationship. It involves naming and categorizing organisms into hierarchical groups to show their evolutionary relationships. Choice A, 'Biology,' is incorrect as it is the broader field of science that encompasses the study of living organisms. Choice C, 'Grouping,' is incorrect as it is a general term that does not specifically refer to the systematic classification of organisms. Choice D, 'Nomenclature,' is incorrect as it refers to the system of naming organisms rather than the classification based on physical characteristics and natural relationships.