Nursing Elites

1. Prokaryotic cells:

• A. Have a nucleus
• B. Have a capsule
• C. Have membrane-bound organelles
• D. Cannot move on their own

Correct answer: B

Rationale: Prokaryotic cells do not have a nucleus or membrane-bound organelles. One characteristic feature of prokaryotic cells is the presence of a capsule, which is a protective layer outside the cell wall. This capsule helps the prokaryotic cell adhere to surfaces, evade the host immune system, and protect against desiccation. Choice A is incorrect because prokaryotic cells lack a nucleus. Choice C is incorrect as prokaryotic cells do not have membrane-bound organelles. Choice D is incorrect as prokaryotic cells can move using structures like flagella or pili.

2. Which, if any, of the following statements about the biosphere is correct?

• A. The biosphere is the part of the Earth that supports life.
• B. The biosphere encompasses the entire surface of the Earth.
• C. A and B are correct.
• D. None of these statements is correct.

Correct answer: A

Rationale: Statement A is correct. The biosphere refers to the part of the Earth where life exists, including the land, water bodies, and atmosphere. It is the zone where living organisms and ecosystems exist. Statement B is incorrect because the biosphere covers various ecosystems on Earth but does not encompass the entire surface of the planet. The biosphere includes regions such as the lithosphere (land), hydrosphere (water bodies), and atmosphere, but not every part of the Earth's surface. Therefore, option C, stating both A and B are correct, is inaccurate. The correct answer is option A, as it accurately defines the biosphere.

3. Which of the following is a protein?

• A. cellulose
• B. hemoglobin
• C. estrogen
• D. ATP

Correct answer: B

Rationale: The correct answer is 'hemoglobin' because it is a protein that carries oxygen in the blood. Cellulose is a carbohydrate found in the cell walls of plants, not a protein. Estrogen is a hormone, not a protein. ATP (adenosine triphosphate) is a molecule that carries energy within cells, not a protein.

4. Why is DNA important for the metabolic activities of the cell?

• A. It initiates cellular mitosis.
• B. It provides cell wall stability.
• C. It increases glucose absorption.
• D. It controls the synthesis of enzymes.

Correct answer: D

Rationale: DNA is important for the metabolic activities of the cell because it controls the synthesis of enzymes. Enzymes are essential for catalyzing metabolic reactions in the cell. Choices A, B, and C are incorrect because DNA is not directly involved in cellular mitosis, cell wall stability, or glucose absorption.

5. 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.

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