What is the hormone responsible for the maintenance of the endometrium during pregnancy and the maturation of mammary gland tissue?

Correct Answer: D

Rationale: The correct answer is D: Progesterone. Progesterone is essential for maintaining the endometrium during pregnancy by promoting its growth and preventing contractions. It also plays a crucial role in preparing the mammary glands for lactation. Estrogen (A) is important in the menstrual cycle but not specifically for maintaining the endometrium during pregnancy. Human chorionic gonadotropin (hCG) (B) is produced by the placenta and is primarily involved in supporting pregnancy and detecting pregnancy tests. Prolactin (C) is responsible for milk production but is not directly related to the maintenance of the endometrium or mammary gland tissue during pregnancy.

Correct Answer: D

Rationale: The correct answer is D (24 weeks) because alveoli formation and fetal breathing movements are typically observed during the late second trimester, around 24 weeks. At this stage, the lungs have developed sufficiently to support breathing outside the womb. Choices A (12 weeks), B (6 weeks), and C (20 weeks) are incorrect because alveoli formation and breathing movements do not occur as early as these time points in the pregnancy. Fetal breathing movements are a crucial sign of lung maturation and readiness for extrauterine life, which is why the correct answer is 24 weeks.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.