Nursing Elites

1. Which type of immune cell does the human immunodeficiency virus (HIV) target and destroy?

• A. Neutrophils
• B. Macrophages
• C. Helper T cells
• D. Memory B cells

Correct answer: C

Rationale: HIV targets and destroys Helper T cells, which are vital for coordinating the immune response against infections. The destruction of Helper T cells weakens the immune system, leading to acquired immunodeficiency syndrome (AIDS). Neutrophils (Choice A) are primarily involved in acute inflammatory responses and fighting bacterial infections. Macrophages (Choice B) play a role in phagocytosis and antigen presentation but are not the primary target of HIV. Memory B cells (Choice D) are responsible for mounting a quicker and more robust antibody response upon re-exposure to a pathogen, but they are not the main target of HIV infection.

2. What does the term 'dilution' refer to in a solution?

• A. Adding more solvent to decrease concentration
• B. Adding more solute to increase concentration
• C. Reducing the temperature to increase solubility
• D. Increasing pressure to increase solubility

Correct answer: A

Rationale: The term 'dilution' in a solution refers to adding more solvent to decrease the concentration of the solution. Dilution involves reducing the concentration of the solute in the solution by increasing the amount of solvent. Choice B is incorrect because adding more solute would increase the concentration, not decrease it. Choices C and D are also incorrect as they relate to factors affecting solubility, not dilution specifically. Therefore, choice A is the correct answer as it accurately defines the process of dilution in a solution.

3. When a person pushes a box across the floor, which of the following forces is NOT doing work?

• A. The person's pushing force
• B. The normal force from the floor
• C. The gravitational force on the box
• D. The frictional force between the box and the floor

Correct answer: B

Rationale: The normal force from the floor is perpendicular to the direction of motion of the box, so it does not contribute to the work being done. Work is only done by forces acting in the direction of motion of an object. In this case, the normal force is acting at a right angle to the motion, hence it does not perform any work on the box. The person's pushing force, the gravitational force, and the frictional force are all acting in the direction of motion of the box, so they contribute to the work being done in moving the box across the floor.

4. A large geographic area characterized by similar climate, plants, and animals is called a:

• A. Population
• B. Community
• C. Biome
• D. Ecosystem

Correct answer: C

Rationale: A) Population refers to a group of individuals of the same species living in a specific area. B) Community refers to all the populations of different species living and interacting in a particular area. C) Biome is a large geographic area characterized by similar climate, plants, and animals. Biomes are defined by factors such as temperature, precipitation, and vegetation types. D) Ecosystem refers to a community of living organisms interacting with each other and their physical environment. An ecosystem can be part of a biome.

5. In the cardiovascular system, what does the term 'double circulation' refer to?

• A. The separation of oxygenated and deoxygenated blood flow within the heart.
• B. The regulation of blood pressure through vasoconstriction and vasodilation.
• C. The cyclic contraction and relaxation of the heart muscle.
• D. The existence of two separate circulatory pathways, one for the lungs and one for the body.

Correct answer: D

Rationale: The term 'double circulation' in the cardiovascular system refers to the existence of two separate circulatory pathways, one for the lungs (pulmonary circulation) and one for the body (systemic circulation). Oxygen-poor blood is pumped from the heart to the lungs for oxygenation, and then oxygen-rich blood is pumped from the lungs back to the heart to be circulated to the rest of the body. Choices A, B, and C are incorrect as they do not accurately describe the concept of 'double circulation.' Choice A refers to the separation of oxygenated and deoxygenated blood within the heart, choice B relates to blood pressure regulation mechanisms, and choice C describes the cardiac muscle's contraction and relaxation, none of which define 'double circulation' in the context of the cardiovascular system.

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