Nursing Elites

1. Do chromosomes get longer as a cell ages?

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

Correct answer: B

Rationale: Chromosomes do not get longer as a cell ages. In fact, chromosomes condense and become more compact during cell division to ensure proper segregation. Choice A is incorrect because chromosomes do not elongate with age. Choice C is not the correct answer as there is scientific evidence to support that chromosomes do not lengthen over time. Choice D is not the right option as the correct answer is 'False' in this case.

2. Which of the following illustrates a positive feedback mechanism?

• A. Maintaining blood pressure
• B. Uterine contractions during childbirth
• C. Body temperature control
• D. Control of blood sugar

Correct answer: B

Rationale: The correct answer is uterine contractions during childbirth. This is an example of a positive feedback mechanism where the initial stimulus (contractions) leads to an increase in intensity and frequency, ultimately resulting in childbirth. In contrast, choices A, C, and D (maintaining blood pressure, body temperature control, and control of blood sugar) are examples of negative feedback mechanisms. These mechanisms work to maintain stability by counteracting any deviations from the set point, rather than amplifying the response like in a positive feedback mechanism.

3. Which of the following is the measurement of the percentage of red blood cells in whole blood?

• A. Hematocrit
• B. Hemoglobin
• C. Mean corpuscular volume
• D. Reticulocyte count

Correct answer: A

Rationale: The correct answer is 'Hematocrit.' Hematocrit is the measurement of the percentage of red blood cells in whole blood. It is used to diagnose conditions such as anemia and dehydration. Choice B, 'Hemoglobin,' measures the amount of hemoglobin in the blood, not the percentage of red blood cells. Choice C, 'Mean corpuscular volume,' measures the average volume of a red blood cell, not the percentage of red blood cells. Choice D, 'Reticulocyte count,' measures the percentage of young red blood cells in the blood, not the percentage of red blood cells.

4. 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.

5. 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.

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