Nursing Elites

1. What pigment is responsible for the yellow color of bananas?

• A. Potassium
• B. Calcium
• C. Phosphorus
• D. Carotene

Correct answer: D

Rationale: Carotene is the pigment responsible for the yellow color of bananas. It belongs to a group of plant pigments called carotenoids, which are responsible for giving fruits and vegetables their vibrant colors, including the yellow hue of bananas. Potassium, calcium, and phosphorus are essential minerals found in bananas but are not responsible for their yellow color.

2. Which of the following is responsible for carrying oxygenated blood from the heart to the body?

• A. Vein
• B. Artery
• C. Capillary
• D. Lymphatic vessel

Correct answer: B

Rationale: The correct answer is B: Artery. Arteries carry oxygenated blood away from the heart to the body. Veins carry deoxygenated blood back to the heart, capillaries are tiny blood vessels where gas exchange occurs, and lymphatic vessels are part of the lymphatic system, which is responsible for draining excess fluid from tissues and transporting white blood cells.

3. In an SN2 reaction, what affects the rate of the reaction?

• A. Only the concentration of the nucleophile
• B. Only the concentration of the electrophile
• C. Neither the concentration of the nucleophile nor the electrophile
• D. Both the concentration of the nucleophile and the electrophile

Correct answer: D

Rationale: In an SN2 reaction, the rate of the reaction is affected by both the concentration of the nucleophile and the electrophile. The rate-determining step involves the nucleophile attacking the electrophile, so the concentrations of both species will impact the reaction rate. Increasing the concentration of the nucleophile increases the frequency of nucleophilic attacks, while increasing the concentration of the electrophile provides more opportunities for the nucleophile to react. Therefore, the correct answer is that both the concentration of the nucleophile and the electrophile affect the rate of the SN2 reaction. Choices A, B, and C are incorrect as they do not consider the interplay between the nucleophile and the electrophile in determining the overall reaction rate in an SN2 mechanism.

4. What is the main function of calcitonin, a hormone produced by the thyroid gland?

• A. Stimulate metabolism and heat production
• B. Increase calcium absorption from the intestines
• C. Enhance bone growth and development
• D. Lower blood calcium levels

Correct answer: D

Rationale: Calcitonin is a hormone produced by the thyroid gland that primarily functions to lower blood calcium levels. It achieves this by inhibiting bone breakdown and promoting calcium excretion by the kidneys. Therefore, the correct answer is D as it reflects the main role of calcitonin in calcium homeostasis. Choices A, B, and C are incorrect as they do not align with the primary function of calcitonin. Calcitonin does not stimulate metabolism and heat production (Choice A), increase calcium absorption from the intestines (Choice B), or enhance bone growth and development (Choice C).

5. What is the function of platelets in the blood?

• A. To transport oxygen
• B. To clot blood
• C. To fight infection
• D. To transport nutrients

Correct answer: B

Rationale: Platelets play a crucial role in clotting blood to prevent excessive bleeding when injuries occur. They are responsible for initiating the coagulation process by forming clots at the site of injury, sealing the damaged blood vessels, and preventing further blood loss. Platelets do not primarily transport oxygen, fight infection, or transport nutrients. While red blood cells are responsible for carrying oxygen, white blood cells are involved in fighting infections, and nutrients are transported by plasma, platelets' main function is related to hemostasis and wound healing.

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