The endocrine gland(s) that makes insulin is the:

Correct Answer: A

Rationale: The correct answer is A: pancreas. The pancreas is responsible for producing insulin, a hormone that helps regulate blood sugar levels. It is located near the stomach and plays a crucial role in the endocrine system. The other choices (B: adrenal glands, C: thyroid gland, D: pituitary gland) do not produce insulin. Adrenal glands produce hormones like adrenaline and cortisol, thyroid gland produces hormones like thyroxine, and the pituitary gland produces various hormones that regulate other endocrine glands. Therefore, the pancreas is the only gland among the options that produces insulin, making it the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Beta cells. Beta cells in the pancreas are responsible for secreting insulin. Insulin helps regulate blood sugar levels. Alpha cells (A) secrete glucagon, Delta cells (C) secrete somatostatin, both involved in glucose metabolism, but not insulin secretion. Choice D is incorrect as the pancreas does contain cells that secrete insulin.

Correct Answer: B

Rationale: Step-by-step rationale for why choice B is correct: 1. Hypersecretion of cortisol is a hallmark of Cushing's syndrome. 2. Excessive cortisol levels can lead to symptoms like weight gain, high blood pressure, and muscle weakness. 3. Cushing's syndrome is characterized by an overactive adrenal gland producing too much cortisol. 4. Addison's disease (choice A) is caused by adrenal insufficiency, leading to low cortisol levels. 5. Acromegaly (choice C) is a growth hormone disorder, not related to cortisol. 6. Dwarfism (choice D) is typically due to growth hormone deficiency, not cortisol excess. Summary: Choice B is correct because hypersecretion of cortisol is specifically associated with Cushing's syndrome, causing a range of symptoms related to excess cortisol production. Choices A, C, and D are incorrect as they are not directly related to cortisol hypersecretion.

Correct Answer: B

Rationale: The correct answer is B: cellular mutations occur. Hormones typically act through binding to specific receptors on target cells to initiate a signaling cascade. This process does not involve inducing mutations in the cell's DNA. Plasma membrane permeability changes, enzyme activation/inactivation, and stimulation of mitosis are all well-established mechanisms of hormone action. Therefore, B is the correct answer as it does not align with the usual mechanisms by which hormones exert their effects.

Correct Answer: B

Rationale: The correct answer is B because the endocrine system releases hormones into the bloodstream, allowing them to reach all parts of the body simultaneously and produce widespread responses. In contrast, the nervous system sends signals through nerve cells, which can only target a small number of specific cells. This difference in distribution and reach of signals is a key distinction between the endocrine and nervous systems. Choice A is incorrect because a single hormone can indeed target multiple responses in different parts of the body, similar to how a nerve signal can affect multiple cells along its path. Choice C is incorrect as nerve cells and the endocrine system can interact and influence each other's functions, such as in the case of stress response involving both systems. Choice D is incorrect because endocrine hormones can have broad effects on various organs and tissues, not limited to a small number of precise responses.