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What is the function of the myelin sheath in a neuron?
- A. To transmit electrical impulses
- B. To insulate and speed up electrical signals
- C. To produce neurotransmitters
- D. To protect the neuron from damage
Correct Answer: B
Rationale: The myelin sheath serves to insulate neurons and accelerate the transmission of electrical signals along the axon. This insulation helps in the efficient conduction of nerve impulses by preventing signal loss or leakage. Choice A is incorrect because the myelin sheath does not transmit electrical impulses itself but rather helps in the conduction. Choice C is incorrect as the myelin sheath is not responsible for producing neurotransmitters. Choice D is also incorrect as the primary function of the myelin sheath is not to protect the neuron from damage. Therefore, the correct answer is B, as it accurately describes the function of the myelin sheath in a neuron.
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Which type of reasoning has the FBI agent used?
- A. Deductive Reasoning
- B. Conductive Reasoning
- C. Quantitative Reasoning
- D. Inductive Reasoning
Correct Answer: D
Rationale: The correct answer is D: Inductive Reasoning. Inductive reasoning involves drawing general conclusions from specific observations or instances. In this case, the FBI agent is creating a theory based on observations of specific cases rather than applying a general rule to a specific situation (which would be deductive reasoning). Conductive reasoning is not a recognized type of reasoning, and quantitative reasoning involves interpreting and analyzing quantitative information.
Where does sperm production occur?
- A. Prostate gland
- B. Seminal vesicles
- C. Scrotum
- D. Seminiferous tubules
Correct Answer: D
Rationale: Sperm production occurs in the seminiferous tubules within the testes. These tubules are responsible for spermatogenesis, the process of sperm creation. The prostate gland and seminal vesicles contribute to seminal fluid production, while the scrotum houses the testes but does not produce sperm. Therefore, choices A, B, and C are incorrect as they are not sites for sperm production.
What is the role of the spleen in the body?
- A. To produce bile
- B. To filter blood and remove old red blood cells
- C. To produce red blood cells
- D. To store fat
Correct Answer: B
Rationale: The correct answer is B. The spleen acts as a blood filter, removing old or damaged red blood cells. It also plays a role in immune responses, storing blood reserves, and helping to fight infection. The production of bile is primarily associated with the liver, not the spleen. While the bone marrow is responsible for red blood cell production, the spleen's main functions do not include this process. Storing fat is not a primary function of the spleen.
What is the purpose of sodium bicarbonate when released into the lumen of the small intestine?
- A. It works to chemically digest fats in the chyme.
- B. It decreases the pH of the chyme to prevent harm to the intestine.
- C. It works to chemically digest proteins in the chyme.
- D. It increases the pH of the chyme to prevent harm to the intestine.
Correct Answer: D
Rationale: Sodium bicarbonate, when released into the lumen of the small intestine, functions to increase the pH of the acidic chyme coming from the stomach. This increase in pH helps neutralize the acidity of the chyme, creating a more optimal environment for the digestive enzymes in the small intestine to function properly. Maintaining a slightly basic pH in the small intestine is crucial for overall digestion and absorption of nutrients. Choices A, B, and C are incorrect. Sodium bicarbonate does not chemically digest fats or proteins in the chyme, and it does not decrease the pH of the chyme as it actually increases the pH to prevent harm to the intestine.
Which of the following correctly identifies a difference between the primary and secondary immune response?
- A. In the secondary response, macrophages migrate to the lymph nodes to present the foreign microorganism to helper T lymphocytes.
- B. The humoral immunity that characterizes the primary response is coordinated by B lymphocytes.
- C. The primary response is quicker and more powerful than the secondary response.
- D. Suppressor T cells are activated in the secondary response to prevent an overactive immune response.
Correct Answer: C
Rationale: The correct answer is C. The primary immune response is slower and less powerful compared to the secondary immune response. During the primary response, immune cells encounter the antigen for the first time, necessitating the activation and proliferation of specific immune cells. In contrast, the secondary response benefits from memory cells that quickly recognize the antigen, enabling a faster and more potent immune response. Choices A, B, and D are incorrect. While macrophages play a role in presenting antigens to T cells, this is not a defining difference between primary and secondary responses. Humoral immunity involves B lymphocytes in both primary and secondary responses, so it does not differentiate the two. Suppressor T cells primarily function to regulate the immune response but are not a key factor distinguishing primary from secondary responses.