Nursing Elites

1. Select the option that best shows complementary base pairing in DNA:

• A. A and G
• B. A and C
• C. A and A
• D. A and T

Correct answer: D

Rationale: The correct answer is D. A purine (A) must pair with a pyrimidine (T) in DNA. This eliminates options A and C as they do not follow the rule of complementary base pairing. Adenine (A) always pairs with thymine (T) due to their specific shape and bonding properties in DNA structure. Choice B is incorrect because adenine does not pair with cytosine in DNA.

2. How many chromosomes do sperm and egg produce in meiosis?

• A. 46
• B. 23
• C. 45
• D. 24

Correct answer: B

Rationale: Sperm and egg cells undergo meiosis to form gametes with half the number of chromosomes found in somatic cells. Each sperm and egg cell produces 23 chromosomes through meiosis. Choice A is incorrect because 46 chromosomes represent the diploid number found in somatic cells. Choice C is incorrect as it is an uncommon number for chromosome production in human gametes. Choice D is incorrect as the total number of chromosomes in sperm or egg cells is 23, not 24.

3. During which phase of mitosis do the chromosomes align in the center of the cell?

• A. Prophase
• B. Metaphase
• C. Telophase
• D. Anaphase

Correct answer: B

Rationale: The correct answer is Metaphase. During Metaphase, the chromosomes line up along the center of the cell's equator, forming the metaphase plate. This alignment ensures that during the subsequent phase, Anaphase, the sister chromatids can separate and move towards opposite poles. Prophase is the initial phase of mitosis where chromosomes condense and the nuclear envelope breaks down. Telophase is the final phase of mitosis where two new nuclei form.

4. Which of the following are considered the most important molecules in biology?

• A. Carbohydrates, lipids, protein, and nucleic acids
• B. Carbohydrates, lipids, protein, and calcium
• C. Carbohydrates, lipids, protein, and sulfur
• D. Carbohydrates, lipids, protein, and iron

Correct answer: A

Rationale: The correct answer is A: Carbohydrates, lipids, protein, and nucleic acids are considered the most important molecules in biology. Carbohydrates are essential for providing energy, lipids for storing energy and forming cell membranes, proteins for various structural and functional roles, and nucleic acids (DNA and RNA) for storing genetic information. Choices B, C, and D are incorrect because while carbohydrates, lipids, and proteins are crucial biomolecules, calcium, sulfur, and iron are not considered among the most important molecules in biology.

5. The apical side of an epithelial cell:

• A. Is exposed to fluid or air
• B. Is on the bottom side of the cell
• C. Does not allow any substances to pass through
• D. None of the above

Correct answer: A

Rationale: The apical side of an epithelial cell is the top side, which is typically exposed to fluids, air, or the inside of an organ. This side allows substances to pass through it, facilitating the absorption, secretion, or excretion of various substances. Choice B is incorrect as the apical side is not on the bottom but the top side. Choice C is incorrect as the apical side does allow substances to pass through. Choice D is incorrect as there are characteristics associated with the apical side.

Similar Questions