Nursing Elites

1. Which vitamin plays a crucial role in calcium absorption in the small intestine?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin E

Correct answer: C

Rationale: The correct answer is Vitamin D. Vitamin D plays a crucial role in calcium absorption in the small intestine by enhancing the absorption of calcium and phosphorus. This helps in regulating the levels of these minerals in the body, which are essential for maintaining healthy bones. Vitamin A (Choice A) is important for vision and immune function, but it is not directly related to calcium absorption. Vitamin C (Choice B) is primarily known for its role in collagen synthesis and antioxidant functions, not calcium absorption. Vitamin E (Choice D) acts as an antioxidant and is not directly involved in calcium absorption in the small intestine.

2. Microfilaments and microtubules are both components of the cytoskeleton, but they have different functions. Which of these describes microfilaments?

• A. Provide structural support and shape
• B. Facilitate cell movement and contraction
• C. Form the mitotic spindle during cell division
• D. Transport materials within the cell

Correct answer: A

Rationale: Microfilaments are thin, solid rods made of the protein actin and are primarily responsible for providing structural support to the cell and determining its shape. While they also play a role in cell movement, their main function is related to maintaining the structural integrity of the cell. Choice B, 'Facilitate cell movement and contraction,' describes microtubules, which are responsible for facilitating cell movement, providing structural support, and aiding in cell division. Choice C, 'Form the mitotic spindle during cell division,' specifically refers to the function of microtubules in forming the mitotic spindle. Choice D, 'Transport materials within the cell,' is characteristic of microtubules that are involved in intracellular transport of organelles and materials within the cell.

3. Which of the following neurotransmitters slows down the activity of neurons to prevent overexcitation?

• A. Acetylcholine
• B. Dopamine
• C. GABA
• D. Serotonin

Correct answer: C

Rationale: The correct answer is C: GABA (gamma-aminobutyric acid). GABA is an inhibitory neurotransmitter that slows down neuronal activity, helping to prevent overexcitation in the brain. It counterbalances the effects of excitatory neurotransmitters like glutamate, playing a crucial role in maintaining the balance of neuronal activity in the brain. Acetylcholine (Choice A) is primarily an excitatory neurotransmitter involved in muscle movement and cognitive functions. Dopamine (Choice B) plays a role in reward-motivated behavior and motor control. Serotonin (Choice D) is involved in regulating mood, appetite, and sleep but is not primarily responsible for slowing down neuronal activity to prevent overexcitation.

4. Which of the following systems does not include a transportation network throughout the body?

• A. Cardiovascular system
• B. Endocrine system
• C. Immune system
• D. Nervous system

Correct answer: B

Rationale: The endocrine system does not include a transportation network throughout the body. While the cardiovascular system transports blood, oxygen, and nutrients, the immune system has lymphatic vessels for immune cell transportation, and the nervous system transmits signals via neurons. In contrast, the endocrine system coordinates bodily functions by releasing hormones directly into the bloodstream, which then act on target organs or tissues. This delivery mechanism is different from the continuous transportation networks found in the other systems listed, making the endocrine system the correct choice for this question.

5. A car is moving in a circle at a constant speed. Which of the following is NOT true about its motion?

• A. It has a constant centripetal acceleration
• B. Its tangential velocity remains constant
• C. It experiences a force directed towards the center of the circle
• D. It covers the same distance in equal time intervals along its circular path

Correct answer: B

Rationale: In circular motion at a constant speed, the car has a constant centripetal acceleration (choice A), experiences a force directed towards the center of the circle (choice C), and covers the same distance in equal time intervals along its circular path (choice D). However, the tangential velocity of an object in circular motion at a constant speed changes continuously as it moves around the circle, so it is not constant (choice B). The change in tangential velocity allows the car to maintain its motion in a circular path despite moving at a constant speed. Choice A is incorrect because centripetal acceleration is indeed present to keep the car moving in a circular path. Choice C is incorrect as a force towards the center is required to keep the car in circular motion. Choice D is incorrect because the car covers equal distances in equal time intervals to maintain its circular trajectory.

Similar Questions