Nursing Elites

1. What is the difference between active and passive immunity?

• A. Active immunity is short-lived, while passive immunity is long-lasting.
• B. Active immunity involves the body's own immune response, while passive immunity provides immediate protection through antibodies from another source.
• C. Active immunity only protects against bacterial infections, while passive immunity works against both bacteria and viruses.
• D. Passive immunity requires repeated vaccinations, while active immunity is a one-time process.

Correct answer: B

Rationale: Active immunity involves the body's own immune response, where the individual's immune system produces antibodies in response to exposure to a pathogen or vaccine. This type of immunity is long-lasting because the immune system 'remembers' the pathogen and can mount a rapid response upon re-exposure. In contrast, passive immunity provides immediate protection through the transfer of pre-formed antibodies from another source, such as through maternal antibodies crossing the placenta or receiving antibodies through an injection. Passive immunity is short-lived because the transferred antibodies eventually degrade and are not produced by the recipient's immune system. Choice A is incorrect because active immunity is generally long-lasting, as it involves the production of antibodies by the individual's immune system. Choice C is incorrect as both active and passive immunity can work against various pathogens, not limited to bacteria or viruses. Choice D is incorrect as passive immunity does not require repeated vaccinations but provides temporary protection through the transfer of antibodies from an external source.

2. What is the difference between a pure substance and a mixture?

• A. Pure substances have a fixed composition, mixtures don't.
• B. Mixtures have a fixed composition, pure substances don't.
• C. Pure substances can be in any state, mixtures are not always solids.
• D. Pure substances are always elements, mixtures are always compounds.

Correct answer: A

Rationale: Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule with fixed proportions. This composition does not vary. On the other hand, mixtures are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. Choice A is correct as it accurately distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures. Choice B is incorrect because mixtures, not pure substances, have variable compositions. Choice C is incorrect as both pure substances and mixtures can exist in different states. Choice D is incorrect because pure substances can be compounds as well, not exclusively elements, and mixtures can contain elements and compounds.

3. Which of the following describes the general function of cytokines in the immune system?

• A. They communicate between cells to instigate an immune response.
• B. They inhibit blood clotting during inflammation responses.
• C. They bind to specific pathogens to increase pathogen mass.
• D. They transport pathogens trapped in mucus to be destroyed in the stomach.

Correct answer: A

Rationale: The correct answer is A: 'They communicate between cells to instigate an immune response.' Cytokines are signaling molecules that act as messengers between cells in the immune system, playing a vital role in coordinating and regulating immune responses. They communicate with various immune cells to initiate appropriate responses against pathogens. Choice B is incorrect because cytokines do not inhibit blood clotting but rather regulate immune responses. Choice C is incorrect as cytokines do not bind to specific pathogens to increase their mass; instead, they regulate the immune response. Choice D is also incorrect because cytokines do not transport pathogens trapped in mucus to the stomach for destruction; they primarily function as signaling molecules within the immune system.

4. Which part of the brain is responsible for balance and coordination?

• A. Cerebellum
• B. Cerebrum
• C. Hypothalamus
• D. Thalamus

Correct answer: A

Rationale: The correct answer is the cerebellum. It plays a vital role in balance and coordination by controlling motor functions, precision, and timing of movements. The cerebrum is primarily involved in higher brain functions such as thinking and problem-solving. The hypothalamus regulates essential bodily functions like temperature and hunger, while the thalamus serves as a relay station for sensory information, directing it to the appropriate areas of the brain for processing.

5. During vigorous exercise, why does the respiratory rate increase?

• A. Meet the increased demand for oxygen in working muscles
• B. Eliminate excess carbon dioxide more slowly
• C. Conserve energy for physical activity
• D. Decrease the amount of oxygen delivered to the body

Correct answer: A

Rationale: During vigorous exercise, the muscles require more oxygen to produce energy for physical activity. The increased respiratory rate helps to deliver more oxygen to the working muscles to meet this demand. This process is essential for sustaining physical activity and preventing fatigue. Choice A is the correct answer as it accurately describes the purpose of the increased respiratory rate during vigorous exercise. Choices B, C, and D are incorrect. Choice B, 'Eliminate excess carbon dioxide more slowly,' is inaccurate as the primary reason for the increased respiratory rate during exercise is to meet the increased demand for oxygen, not to eliminate carbon dioxide. Choice C, 'Conserve energy for physical activity,' is incorrect because increasing the respiratory rate actually expends energy to meet the oxygen demand of the working muscles. Choice D, 'Decrease the amount of oxygen delivered to the body,' is incorrect as the increased respiratory rate is specifically to deliver more oxygen to the body during exercise.

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