The pituitary hormone that stimulates the male testes to produce sperm and stimulates the development of the follicle in the female on a monthly cycle is:

Correct Answer: D

Rationale: The correct answer is D: follicle-stimulating hormone (FSH). FSH is produced by the pituitary gland and plays a crucial role in both male and female reproductive systems. In males, FSH stimulates the testes to produce sperm. In females, FSH stimulates the development of ovarian follicles, which contain eggs. This hormone is essential for the process of ovulation and the menstrual cycle. A: Growth hormone is not directly involved in the reproductive system but rather promotes overall growth and development. B: Luteinizing hormone (LH) is responsible for ovulation and the production of testosterone in males. It does not directly stimulate sperm production or follicle development. C: Prolactin is primarily involved in milk production and has no direct role in sperm production or follicle development.

Correct Answer: C

Rationale: The correct answer is C: pancreas. The pancreas is classified as both an endocrine gland, producing hormones like insulin and glucagon, and an exocrine gland, secreting digestive enzymes into the small intestine. This dual functionality makes it unique among the other options. The hypothalamus (A) is primarily an endocrine gland involved in hormone regulation, while the thymus gland (B) is solely an endocrine gland responsible for T-cell maturation. The pituitary gland (D) is also an endocrine gland that regulates various bodily functions but does not have exocrine functions like the pancreas.

Correct Answer: D

Rationale: The correct answer is D: Sweat. Sweat glands are not considered ductless glands as they secrete sweat through ducts onto the skin surface. Adrenal, Pituitary, and Thyroid glands are all ductless endocrine glands that secrete hormones directly into the bloodstream. Adrenal glands produce hormones like cortisol and adrenaline, Pituitary gland secretes hormones that regulate various bodily functions, and Thyroid gland produces hormones that control metabolism. Therefore, sweat gland is the only option that does not fit the criteria of a ductless gland, making it the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Gigantism. Gigantism is caused by excess growth hormone production from the pituitary gland before puberty, leading to abnormal growth and height. Dwarfism (choice A) is the opposite condition, characterized by stunted growth. Goiter (choice C) is a thyroid disorder, not related to pituitary gland. Cretinism (choice D) is a condition caused by thyroid hormone deficiency, not pituitary gland disorder.

Correct Answer: B

Rationale: The correct answer is B because steroid hormones are lipid-soluble, allowing them to easily diffuse through the plasma membranes of target cells. Once inside the cell, they bind to intracellular receptors to regulate gene expression. Choice A is incorrect because steroid hormones do not catalyze cyclic AMP; that is a function of peptide hormones. Choice C is incorrect because steroid hormones do not enter the nucleus directly but bind to intracellular receptors in the cytoplasm. Choice D is incorrect because while steroid hormones do activate genes to transcribe mRNA for protein synthesis, the initial step involves binding to receptors in the cytoplasm, not directly activating gene transcription.