Nursing Elites

1. How many pairs of chromosomes are in a human cell?

• A. 46
• B. 23
• C. 64
• D. 32

Correct answer: B

Rationale: The correct answer is B: 23. Humans have 23 pairs of chromosomes, totaling 46 chromosomes. Each pair consists of one chromosome inherited from the mother and one from the father, making a total of 46 chromosomes in a human cell. Choice A (46) is incorrect as it represents the total number of chromosomes, not pairs. Choice C (64) and D (32) are incorrect as they do not reflect the accurate number of chromosome pairs in a human cell.

2. Which of the following cell organelles is the site of lipid synthesis?

• A. smooth endoplasmic reticulum
• B. ribosome
• C. rough endoplasmic reticulum
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is the smooth endoplasmic reticulum. This organelle lacks ribosomes on its surface, unlike the rough endoplasmic reticulum, which is involved in protein synthesis. The enzymes present in the smooth endoplasmic reticulum are responsible for synthesizing lipids such as phospholipids and steroids. Choice B, ribosomes, are responsible for protein synthesis and not lipid synthesis. Choice C, rough endoplasmic reticulum, is involved in protein synthesis due to the presence of ribosomes. Choice D, Golgi apparatus, is responsible for modifying, sorting, and packaging proteins for secretion, not lipid synthesis.

3. Photons, the basic unit of light, are:

• A. Charged particles
• B. Packets of energy with wave-particle duality
• C. Electromagnetic waves only
• D. Always absorbed by matter

Correct answer: B

Rationale: Photons are not charged particles; they are packets of energy that exhibit wave-particle duality, meaning they can behave as both particles and waves. While photons are part of the electromagnetic spectrum, they are not electromagnetic waves themselves but rather discrete energy packets. They are not always absorbed by matter; they can be reflected, transmitted, or scattered.

4. What happens to the density of a gas when its temperature increases at constant pressure?

• A. It increases.
• B. It decreases.
• C. It remains the same.
• D. Information is insufficient.

Correct answer: B

Rationale: When the temperature of a gas increases at constant pressure, the average kinetic energy of the gas molecules increases. This leads to the gas molecules moving faster and spreading out more, which causes them to occupy a larger volume. As a result, the density of the gas decreases because the same number of gas molecules are now distributed over a larger space. Choice A is incorrect because as the gas molecules spread out, the density decreases. Choice C is incorrect because the increase in temperature leads to a decrease in density due to the increased volume occupied by the gas molecules. Choice D is incorrect because with the provided scenario of temperature increase at constant pressure, the effect on density can be determined.

5. What element is responsible for the red color of blood?

• A. Magnesium
• B. Iron
• C. Copper
• D. Zinc

Correct answer: B

Rationale: The correct answer is B: Iron. Hemoglobin, the protein responsible for carrying oxygen in red blood cells, contains iron in its heme group, contributing to the blood's characteristic red color. Magnesium (choice A), copper (choice C), and zinc (choice D) are not responsible for the red color of blood. Magnesium is an essential mineral involved in various physiological processes, copper is a trace element important for enzyme function, and zinc is a micronutrient essential for multiple cellular functions but not related to the red color of blood.

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