Nursing Elites

1. Which organelle is the site of photosynthesis in plant cells?

• A. Mitochondria
• B. Chloroplasts
• C. Ribosomes
• D. Endoplasmic Reticulum

Correct answer: B

Rationale: The correct answer is B: Chloroplasts. Chloroplasts are responsible for conducting photosynthesis in plant cells. They contain chlorophyll, a pigment that captures light energy and converts it into chemical energy through the process of photosynthesis. Mitochondria (choice A) are known as the powerhouse of the cell and are involved in cellular respiration, not photosynthesis. Ribosomes (choice C) are responsible for protein synthesis. The endoplasmic reticulum (choice D) is involved in protein and lipid synthesis and transport within the cell, not photosynthesis.

2. Which of the following is not found within a bacterial cell?

• A. mitochondria
• B. DNA
• C. vesicles
• D. ribosome

Correct answer: A

Rationale: The correct answer is A: mitochondria. Mitochondria are not found in bacterial cells. Bacterial cells lack membrane-bound organelles like mitochondria, which are commonly found in eukaryotic cells. Choices B, C, and D are all components that can be found within a bacterial cell. Bacterial cells contain DNA as their genetic material, vesicles for various cellular functions, and ribosomes for protein synthesis. Therefore, the presence of mitochondria is the distinguishing factor that is not found in bacterial cells, making option A the correct answer.

3. Which cellular structure is largely protective in function?

• A. Mitochondrion
• B. Vacuole
• C. Cell membrane
• D. Ribosome

Correct answer: C

Rationale: The correct answer is C: Cell membrane. The cell membrane, also known as the plasma membrane, is largely protective in function as it serves as a selectively permeable barrier that surrounds the cell, providing structural support and helping to maintain cell integrity. It regulates the movement of substances in and out of the cell, thus protecting the cell from harmful external factors while allowing essential nutrients to enter. Mitochondrion (choice A) is responsible for energy production, not primarily protective. Vacuole (choice B) is mainly involved in storage and transport. Ribosome (choice D) is involved in protein synthesis, not protective functions.

4. Imagine that two parents both carry the recessive gene for cystic fibrosis. Any homozygous recessive offspring will manifest the disease. What percentage of the offspring is predicted to be carriers but not manifest the disease?

• A. 0%
• B. 25%
• C. 50%
• D. 100%

Correct answer: B

Rationale: When both parents carry the recessive gene for cystic fibrosis (homozygous recessive), there is a 25% chance for each offspring to inherit two recessive alleles and, therefore, manifest the disease. There is also a 50% chance for each offspring to inherit one recessive allele and one dominant allele, making them carriers of the disease but not manifest it. Therefore, 25% of the offspring are predicted to be carriers but not manifest the disease. Choice A (0%) is incorrect because there is a portion of offspring that will be carriers. Choice C (50%) is incorrect as this percentage corresponds to carriers who will not manifest the disease. Choice D (100%) is incorrect as not all offspring will be carriers and not manifest the disease.

5. Bacillus subtilis may be described as ___________.

• A. spiral
• B. globular
• C. rod-shaped
• D. grape-like clusters

Correct answer: C

Rationale: Bacillus subtilis is a rod-shaped bacterium. Its name "Bacillus" refers to its rod-like shape, which is a characteristic feature of this bacteria.

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