Nursing Elites

1. What happens when a protein unfolds?

• A. Activation
• B. Denaturation
• C. Renaturation
• D. Folding

Correct answer: B

Rationale: - Activation (Option A) refers to the process of initiating or increasing the activity of a molecule, such as an enzyme. Protein unfolding does not involve activation. - Denaturation (Option B) is the correct answer. Denaturation refers to the process by which a protein loses its three-dimensional structure, leading to the disruption of its function. This can be caused by factors such as heat, pH changes, or chemicals. - Renaturation (Option C) is the process by which a denatured protein regains its native structure and function. Protein unfolding is the opposite of renaturation. - Folding (Option D) is the process by which a protein assumes its functional three-dimensional structure. Unfolding is the reverse process of folding, not folding itself.

2. What is the primary function of the lymphatic system?

• A. Transporting nutrients throughout the body
• B. Removing excess fluids and waste products from tissues
• C. Producing red blood cells
• D. Regulating body temperature

Correct answer: B

Rationale: The primary function of the lymphatic system is to remove excess fluids, waste products, and toxins from tissues. It maintains fluid balance and supports the immune system by transporting lymph, which contains white blood cells, throughout the body. Choice A is incorrect as nutrient transport is primarily handled by the circulatory system. Choice C is incorrect because red blood cells are produced in the bone marrow, not the lymphatic system. Choice D is incorrect as the regulation of body temperature is mainly controlled by the endocrine system and thermoregulatory mechanisms in the body. Therefore, the correct answer is B.

3. Which of the following describes an experiment?

• A. The final math grades for a group of students passing through each year of elementary school are examined.
• B. The health trends of smokers in a small random sample are examined.
• C. Citizens in a local community are surveyed to determine concerns related to the next election.
• D. The effects of a new drug are tested on a group of participants.

Correct answer: D

Rationale: Option D describes an experiment because it involves testing the effects of a new drug on a group of participants. In an experiment, researchers intentionally manipulate an independent variable (in this case, the new drug) to observe its effects on a dependent variable (the participants' health outcomes). This method allows for establishing cause-and-effect relationships between variables, which is a key characteristic of experimental research design. Choices A, B, and C do not represent experiments. Choice A involves observational analysis of math grades, choice B involves observational analysis of health trends, and choice C involves a survey, none of which involve manipulating variables to establish cause-and-effect relationships.

4. Which of the following is NOT a major division of the nervous system?

• A. Peripheral nervous system
• B. Central nervous system
• C. Somatic nervous system
• D. Autonomic nervous system

Correct answer: C

Rationale: The correct answer is C: Somatic nervous system. The major divisions of the nervous system are the central nervous system, which includes the brain and spinal cord, and the peripheral nervous system, which includes all the nerves outside of the central nervous system. The somatic nervous system, which controls voluntary movements and reflexes, is a part of the peripheral nervous system. The autonomic nervous system is another subdivision of the peripheral nervous system that regulates involuntary functions like heart rate and digestion. Therefore, the somatic nervous system is not a major division of the nervous system, making it the correct answer.

5. What is the balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride?

• A. Na + Cl2 -> NaCl
• B. 2Na + Cl2 -> 2NaCl
• C. Na2 + Cl -> 2NaCl
• D. Na + 2Cl -> NaCl2

Correct answer: B

Rationale: In a balanced chemical equation, the number of atoms of each element must be the same on both sides of the equation. When sodium (Na) reacts with chlorine (Cl2) to form sodium chloride (NaCl), we need to ensure the equation is balanced. There are 2 chlorine atoms in Cl2; hence, we need 2 sodium atoms on the left side to balance it. Therefore, the balanced chemical equation is 2Na + Cl2 -> 2NaCl. Choice A is incorrect because it does not have the correct coefficients to balance the equation. Choice C is incorrect as it incorrectly represents the formula of sodium. Choice D is incorrect as it forms NaCl2, which is not the correct compound formed in this reaction.

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