What gland requires iodine in order to produce its hormones?

Correct Answer: D

Rationale: The correct answer is D: Thyroid gland. The thyroid gland requires iodine to produce its hormones, such as thyroxine and triiodothyronine, which are essential for regulating metabolism, growth, and development. Iodine is a crucial component of these thyroid hormones. The other choices (A: Adrenal cortex, B: Pancreas, C: Parathyroid glands) do not require iodine for hormone production and are not involved in the synthesis of thyroid hormones. Therefore, the correct answer is the thyroid gland because it specifically relies on iodine for hormone synthesis, making it the only gland in the list that fits this criteria.

Correct Answer: B

Rationale: The correct answer is B because estrogen is indeed necessary for the maturation of the ovum. Estrogen promotes the development and release of the egg from the ovary during the menstrual cycle. This hormone is crucial for the growth of the follicles in the ovary and prepares the uterus for potential pregnancy. Rationale: A: Progesterone is responsible for maintaining the uterine lining during pregnancy, not for female secondary sex characteristics. C: Estrogen plays a significant role in breast development, so this statement is incorrect. D: Progesterone helps to prepare the uterus for pregnancy by promoting the growth of the uterine lining, not the uterus itself.

Correct Answer: B

Rationale: Correct Answer: B (FSH) Rationale: 1. FSH (Follicle Stimulating Hormone) is secreted by the anterior pituitary gland, not the hypothalamus. 2. PRH (Prolactin Releasing Hormone), CRH (Corticotropin Releasing Hormone), and TRH (Thyrotropin Releasing Hormone) are all hormones secreted by the hypothalamus, involved in regulating pituitary hormone release. 3. Therefore, FSH is the correct answer as it is not directly secreted by the hypothalamus. Summary: - FSH is secreted by the anterior pituitary gland, not the hypothalamus. - PRH, CRH, and TRH are hormones secreted by the hypothalamus. - Understanding the origin of each hormone helps in determining the correct answer.

Correct Answer: D

Rationale: The correct answer is D because hormones alter the activity of target tissues to regulate various physiological processes in the body. Hormones act on specific receptors in target tissues to initiate a response. Option A is incorrect because hormone levels fluctuate to maintain homeostasis. Option B is incorrect because hormones are typically synthesized by endocrine glands, not plasma proteins. Option C is incorrect because hormones are produced throughout life, not just after puberty.

Correct Answer: B

Rationale: The correct answer is B: B12. Vitamin B12 is water-soluble because it dissolves in water, allowing it to be easily absorbed and transported in the bloodstream. It plays a crucial role in nerve function, red blood cell production, and DNA synthesis. Vitamins D, A, and K are fat-soluble vitamins, meaning they are absorbed along with fats in the diet and are stored in the body's fat tissues. Since they are not water-soluble, they require bile for absorption and are stored in the body for longer periods. Hence, B12 is the only water-soluble vitamin among the given choices.