Nursing Elites

1. What is the main function of the nervous system?

• A. To fight infection
• B. To control body movement and coordination
• C. To regulate metabolism
• D. To transport oxygen

Correct answer: B

Rationale: The main function of the nervous system is to control body movement and coordination by transmitting signals between different parts of the body. Choice A is incorrect because the immune system, not the nervous system, is primarily responsible for fighting infections. Choice C is incorrect as regulating metabolism is primarily handled by the endocrine system. Choice D is incorrect because the transportation of oxygen is mainly the function of the circulatory system, specifically the blood.

2. During which phase of the cardiac cycle do the atria contract, pushing blood into the ventricles?

• A. Atrial diastole
• B. Ventricular systole
• C. Atrial systole
• D. Ventricular diastole

Correct answer: C

Rationale: Atrial systole is the phase of the cardiac cycle during which the atria contract, pushing blood into the ventricles. This occurs after the atria have been filled during atrial diastole. Ventricular systole refers to the phase when the ventricles contract to push blood out of the heart, not when the atria contract. Ventricular diastole is the phase when the ventricles relax and fill with blood, not when the atria contract. Therefore, the correct answer is atrial systole as it specifically describes the atrial contraction phase.

3. What property of a substance remains constant regardless of changes in its location in the universe?

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

Correct answer: A

Rationale: Mass is the amount of matter in an object and remains constant regardless of its location in the universe. Weight, on the other hand, is the force of gravity acting on an object and can vary depending on the gravitational pull at different locations. Density and volume can change based on the conditions the substance is in, so they are not constant properties. Therefore, the correct answer is mass as it does not change with changes in location.

4. What happens when a protein unfolds?

• A. Activation
• B. Denaturation
• C. Renaturation
• D. Folding

Correct answer: B

Rationale: - Activation (Option A) refers to the process of initiating or increasing the activity of a molecule, such as an enzyme. Protein unfolding does not involve activation. - Denaturation (Option B) is the correct answer. Denaturation refers to the process by which a protein loses its three-dimensional structure, leading to the disruption of its function. This can be caused by factors such as heat, pH changes, or chemicals. - Renaturation (Option C) is the process by which a denatured protein regains its native structure and function. Protein unfolding is the opposite of renaturation. - Folding (Option D) is the process by which a protein assumes its functional three-dimensional structure. Unfolding is the reverse process of folding, not folding itself.

5. Which of the following statements is true regarding a supersaturated solution?

• A. It is unstable and tends to crystallize
• B. It contains more solute than it could dissolve
• C. It has a higher concentration than a saturated solution
• D. It is rarely encountered in everyday solutions

Correct answer: A

Rationale: A supersaturated solution is unstable and tends to crystallize because it contains more solute than it could dissolve at a given temperature. This excess solute is in a metastable state and can precipitate out if disturbed, leading to the formation of crystals. Option B is incorrect because a supersaturated solution does contain more solute than it could normally dissolve, but it becomes unstable due to this excess solute. Option C is incorrect because while a supersaturated solution does have a higher concentration than a saturated solution, the defining characteristic related to its instability is the excess solute. Option D is incorrect as supersaturated solutions can be encountered in various everyday scenarios, such as certain sugar solutions used in cooking or rock candy production.

Similar Questions