Nursing Elites

1. Which property of matter remains constant regardless of changes in gravity?

• A. Mass
• B. Weight
• C. Volume
• D. Density

Correct answer: A

Rationale: Mass is a measure of the amount of matter in an object and remains constant regardless of changes in gravity. This is because mass is an intrinsic property of an object and does not depend on the gravitational field it is in. Weight, on the other hand, is the force of gravity acting on an object's mass and can vary depending on the strength of gravity. Volume is the amount of space an object occupies, which can change depending on the environment. Density is the mass of an object per unit volume, which can also change with variations in gravity. Therefore, the correct answer is Mass as it remains the same regardless of gravitational changes.

2. Which type of blood vessel carries blood back to the heart?

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

Correct answer: B

Rationale: The correct answer is B: Vein. Veins carry blood back to the heart from various parts of the body, functioning as the vessels that return blood to the heart. Arteries, on the other hand, carry blood away from the heart to different parts of the body to deliver oxygen and nutrients. Capillaries are tiny blood vessels where the exchange of gases, nutrients, and waste products occurs between the blood and tissues. Lymphatic vessels are part of the lymphatic system, responsible for maintaining fluid balance and aiding in immunity. Therefore, the correct choice is B as it directly relates to the blood flow back to the heart.

3. How do hydrogen bonds in water affect its characteristics?

• A. Hydrogen bonds are not polar enough to attract non-polar molecules.
• B. Hydrogen bonds cause water to be less dense when it is a solid than when it is a liquid.
• C. Hydrogen bonds cause water to have high surface tension, allowing some organisms to move across it.
• D. Hydrogen bonds cause water to be a good solvent.

Correct answer: C

Rationale: Hydrogen bonds in water contribute to its high surface tension, enabling some organisms to move across the water's surface. This property is essential for certain insects and small animals that rely on surface tension to move or stay afloat on water. Choice A is incorrect because hydrogen bonds are polar and can attract polar and other charged molecules. Choice B is incorrect as hydrogen bonds make ice less dense than liquid water, which is a unique property. Choice D is incorrect as the ability of water to act as a good solvent is primarily due to its polarity, not just hydrogen bonding.

4. Which of the following is part of the central nervous system?

• A. Spinal cord
• B. Peripheral nerves
• C. Brainstem
• D. Cerebellum

Correct answer: A

Rationale: The correct answer is A: Spinal cord. The central nervous system comprises the brain and spinal cord. The spinal cord plays a crucial role in transmitting information between the brain and the body. Choices B, C, and D are not part of the central nervous system. Peripheral nerves belong to the peripheral nervous system, whereas the brainstem and cerebellum are components of the brain, distinct from the central nervous system.

5. Melatonin is a hormone produced by the pineal gland. What is its primary function?

• A. Regulate blood pressure
• B. Stimulate the digestive system
• C. Control sleep-wake cycles
• D. Maintain bone density

Correct answer: C

Rationale: Melatonin is primarily known for its role in controlling sleep-wake cycles. It is produced by the pineal gland in response to darkness, helping signal the body that it is time to sleep. Melatonin levels typically rise in the evening and stay elevated throughout the night, promoting sleep. Choices A, B, and D are incorrect as melatonin's primary function is not to regulate blood pressure, stimulate the digestive system, or maintain bone density. While melatonin may have some indirect effects on these functions, its main role lies in regulating the circadian rhythm and promoting a restful sleep cycle.

Similar Questions