Nursing Elites

1. Which of the following is not an example of a homeostatic mechanism in the human body?

• A. Shivering when the body temperature falls below normal.
• B. Increasing heart rate and force of contraction when blood pressure falls.
• C. Retaining fluid excessively.
• D. Secreting insulin after a meal to return blood sugar concentration toward normal.

Correct answer: C

Rationale: The correct answer is C. Homeostatic mechanisms aim to maintain internal stability within the body. Choices A, B, and D all represent examples of homeostatic mechanisms. Shivering helps generate heat to raise body temperature back to normal levels. Increasing heart rate and force of contraction work to restore blood pressure. Insulin secretion after a meal helps regulate blood sugar levels. On the other hand, retaining fluid excessively can lead to fluid imbalance rather than maintaining internal stability, making it the incorrect choice.

2. What is the main function of the digestive system?

• A. Formation of cells
• B. Movement of body parts
• C. Absorption of nutrients
• D. Providing oxygen for the extraction of energy from nutrients

Correct answer: C

Rationale: The correct answer is C: Absorption of nutrients. The main function of the digestive system is to break down food into nutrients that can be absorbed by the body to provide energy and support bodily functions. Choice A, 'Formation of cells,' is incorrect as cell formation is not the primary function of the digestive system; it is more related to processes like cell division and growth. Choice B, 'Movement of body parts,' is incorrect as this is more related to the muscular system, which controls body movements. Choice D, 'Providing oxygen for the extraction of energy from nutrients,' is incorrect because providing oxygen is primarily the function of the respiratory system, which is responsible for breathing and oxygen exchange in the body, not the digestive system.

3. In all organisms, what is the basic unit of structure and function?

• A. the atom
• B. the molecule
• C. the macromolecule
• D. the cell

Correct answer: D

Rationale: The correct answer is 'the cell.' Cells are considered the basic unit of structure and function in all living organisms. While atoms are the smallest units of matter, they do not represent the basic unit of structure and function in organisms. Molecules are made up of atoms and can vary in size and complexity, but they are not the fundamental unit of life. Macromolecules are large molecules essential for life processes, but they are composed of atoms and do not function as the basic unit of structure and function in organisms. Therefore, the cell, with its organelles and specialized functions, is the correct answer.

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. 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.

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