Nursing Elites

1. Balance the following redox reaction in acidic solution: I⁻ (aq) + Cr₂O₇²⁻ (aq) -> I₂ (aq) + Cr³⁺ (aq). Identify the oxidizing agent and reducing agent.

• A. I⁻ is oxidized, Cr₂O₇²⁻ is reduced
• B. I⁻ is reduced, Cr₂O₇²⁻ is oxidized
• C. Both I⁻ and Cr₂O₇²⁻ are oxidized
• D. Both I⁻ and Cr₂O₇²⁻ are reduced

Correct answer: B

Rationale: In the given redox reaction, I⁻ is gaining electrons to form I₂, which means I⁻ is being reduced (undergoing reduction). On the other hand, Cr₂O₇²⁻ is losing electrons to form Cr³⁺, indicating that Cr₂O₇²⁻ is being oxidized (undergoing oxidation). Therefore, I⁻ is the reducing agent and Cr₂O₇²⁻ is the oxidizing agent. Choice A is incorrect because I⁻ is being reduced, not oxidized. Choice C is incorrect as both species cannot be oxidized in the same reaction. Choice D is incorrect as both species cannot be reduced in the same reaction.

2. 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.

3. What is the most basic unit of structure in living things?

• A. Cell
• B. Organelle
• C. Oxygen
• D. Pigment

Correct answer: A

Rationale: The cell is indeed the most basic unit of life, forming the foundation of all living organisms. Cells are the building blocks of all living things, containing organelles that perform specific functions. While oxygen is essential for life, it is not a structural unit. Similarly, pigment is a component found within cells but is not the fundamental unit of structure. Therefore, the correct answer is 'A: Cell.'

4. What is the difference between type 1 and type 2 diabetes, both related to insulin and blood sugar?

• A. Type 1 is caused by insulin resistance, type 2 by insulin deficiency.
• B. Type 1 is temporary, type 2 is permanent.
• C. Type 1 affects adults, type 2 affects children.
• D. Type 1 is treated with diet only, type 2 requires medication.

Correct answer: A

Rationale: The correct difference between type 1 and type 2 diabetes lies in their underlying causes. Type 1 diabetes is caused by the body's inability to produce insulin, while type 2 diabetes is characterized by insulin resistance, where the body doesn't effectively use the insulin it produces. Insulin resistance is a key feature of type 2 diabetes, distinguishing it from type 1 where insulin deficiency is the primary issue. Choices B, C, and D are incorrect. Type 1 and type 2 diabetes can both be chronic conditions, affecting individuals of different age groups, and typically require a combination of diet, exercise, and medication for management.

5. What is the primary purpose of conducting an experiment?

• A. to test a hypothesis
• B. to collect data
• C. to identify a control state
• D. to choose variables

Correct answer: A

Rationale: The correct answer is A: 'to test a hypothesis.' The primary purpose of conducting an experiment is to test a hypothesis. This process allows researchers to gather empirical evidence to either support or refute a proposed hypothesis. By systematically manipulating variables and observing outcomes, scientists can draw conclusions about the relationships between these variables. Choice B, 'to collect data,' is a common step within an experiment, but the ultimate goal is to test a specific hypothesis. Choice C, 'to identify a control state,' is not the primary purpose but rather a methodological consideration within an experiment to ensure reliable results. Choice D, 'to choose variables,' is a step that is typically done before conducting the experiment and is not the primary purpose of the experiment itself.

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