Nursing Elites

1. Maintaining a stable internal environment typically requires

• A. positive feedback mechanisms.
• B. an unstable outside environment.
• C. decreased atmospheric pressure.
• D. negative feedback mechanisms.

Correct answer: D

Rationale: The correct answer is 'negative feedback mechanisms.' In biological systems, negative feedback mechanisms help maintain homeostasis by counteracting any deviations from the set point. They work to stabilize internal conditions and keep them within a narrow range. On the other hand, positive feedback mechanisms amplify changes and are not involved in maintaining stability. Choice B, 'an unstable outside environment,' is incorrect as internal stability is independent of external conditions like weather. Choice C, 'decreased atmospheric pressure,' is also incorrect as it does not directly relate to internal homeostasis.

2. Does aging begin in the fetus?

• A. Yes
• B. No
• C. Not Sure
• D. None of the above

Correct answer: A

Rationale: Aging does begin in the fetus. The aging process starts even before birth due to cellular changes and the passage of time. The cells in a fetus undergo growth, division, and aging from the moment of conception. This continual process of cellular aging continues throughout life. Therefore, the statement is true. Choice B is incorrect because aging does initiate during the fetal stage. Choice C is incorrect as the process of aging commences in the fetus. Choice D is incorrect as the correct answer is 'Yes,' indicating that aging does start in the fetus.

3. The maintenance of a steady body temperature in the face of fluctuating environmental conditions illustrates homeostasis.

• A. TRUE
• B. FALSE
• C. Not Sure
• D. None of the above

Correct answer: A

Rationale: The correct answer is True. Homeostasis is the body's ability to maintain a stable internal environment despite external changes. In this case, the maintenance of a steady body temperature despite fluctuations in environmental conditions is a clear example of homeostasis. The body regulates temperature through processes like sweating when it's hot and shivering when it's cold. Choices B, C, and D are incorrect because the statement provided does indeed illustrate the concept of homeostasis, making them inaccurate.

4. An individual with which of the following blood type can receive only blood of that same type?

• A. Type O
• B. Type A
• C. Type B
• D. Type AB

Correct answer: A

Rationale: The correct answer is Type O. Individuals with blood type O can only receive blood from donors with blood type O. This is because type O blood lacks both A and B antigens, so if a person with type O blood receives blood with A, B, or AB antigens, their immune system will recognize these as foreign substances and attack them. Choices B, C, and D are incorrect because individuals with type A can receive blood from A or O donors, individuals with type B can receive blood from B or O donors, and individuals with type AB can receive blood from A, B, AB, or O donors.

5. Which of the following is a role of platelets in hemostasis?

• A. formation of plugs
• B. promotion of vasodilation
• C. conversion of prothrombin to thrombin
• D. activation of calcium

Correct answer: A

Rationale: Platelets play a crucial role in hemostasis by forming plugs to stop bleeding. Choice B is incorrect because platelets do not promote vasodilation; instead, they help in vasoconstriction. Choice C is incorrect as the conversion of prothrombin to thrombin is a function of the coagulation cascade involving various clotting factors, not platelets. Choice D is incorrect as platelets do not directly activate calcium; instead, they play a role in the activation of other clotting factors.

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