Nursing Elites

1. Which organelle is responsible for making proteins?

• A. Ribosome
• B. Chloroplast
• C. Lysosome
• D. Mitochondrion

Correct answer: A

Rationale: Ribosomes are the organelles responsible for protein synthesis within the cell. They are the sites where amino acids are linked together to form proteins based on the instructions carried by mRNA (messenger RNA). Ribosomes can be found free-floating in the cytoplasm or attached to the endoplasmic reticulum, and they play a crucial role in translating genetic information into proteins. Chloroplasts are responsible for photosynthesis, lysosomes are involved in digestion and waste removal, and mitochondria are known as the powerhouse of the cell responsible for energy production through cellular respiration. Therefore, the ribosome is the correct organelle responsible for making proteins.

2. What organelle do plant cells have that functions as storage, waste disposal, and protection?

• A. Nucleus
• B. Mitochondria
• C. Vacuoles
• D. Ribosomes

Correct answer: C

Rationale: Correct! Plant cells have vacuoles that serve as storage centers, help in waste disposal by containing and isolating harmful materials, and contribute to protection by storing toxic substances. The other choices are incorrect because the nucleus contains genetic material, mitochondria are responsible for energy production, and ribosomes are involved in protein synthesis.

3. What are the three main events of the haploid cell cycle?

• A. DNA replication, mitosis, and cytokinesis
• B. DNA replication, meiosis, and cytokinesis
• C. DNA replication, cytokinesis, and degradation
• D. Mitosis, meiosis, and apoptosis

Correct answer: A

Rationale: In the haploid cell cycle, the three main events are DNA replication, where the cell's genetic material is duplicated; mitosis, which is the division of the nucleus to ensure each daughter cell receives a complete set of chromosomes; and cytokinesis, the division of the cell cytoplasm to separate the two daughter cells. Meiosis is not part of the haploid cell cycle as it occurs in diploid cells to produce haploid gametes. Apoptosis is a process of programmed cell death and is not a routine event in the cell cycle. Therefore, the correct answer is A. Choices B, C, and D are incorrect as meiosis and apoptosis are not part of the haploid cell cycle, and degradation is not a typical event in the cell cycle.

4. Cytosine and thymine are known as:

• A. Purines
• B. Pyrimidines
• C. Both
• D. None of the above

Correct answer: B

Rationale: Cytosine and thymine are known as pyrimidines because they have a single carbon ring structure. Purines, on the other hand, have a double-ring structure. Choice A ('Purines') is incorrect because purines have a double-ring structure, unlike cytosine and thymine. Choice C ('Both') is incorrect as it implies they are both purines and pyrimidines, which is not true. Choice D ('None of the above') is incorrect because cytosine and thymine are indeed pyrimidines.

5. How many pairs of chromosomes do all humans have?

• A. 24 pairs
• B. 23 pairs
• C. 22 pairs
• D. 20 pairs

Correct answer: B

Rationale: All humans have 23 pairs of chromosomes, totaling 46 chromosomes. Choice A is incorrect because humans do not have 24 pairs. Choice C is incorrect as humans have 23 pairs, not 22 pairs. Choice D is incorrect as humans have 23 pairs of chromosomes, not 20 pairs.

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