Final answer:
The statement regarding estrogen's role in stimulating the maturation of a dominant follicle, leading to an LH surge that, in conjunction with FSH, triggers ovulation, is true. The correct answer is option a.
Step-by-step explanation:
The statement that estrogen stimulates a dominant follicle to mature, leading to high levels of estrogen triggering an LH surge and, together with FSH, causing ovulation, is true. During a typical menstrual cycle, high estrogen levels initially lead to negative feedback that inhibits FSH, promoting the atresia of all but one of the tertiary follicles. However, as the dominant follicle secretes even higher levels of estrogen, a positive feedback mechanism is triggered, causing the anterior pituitary to release substantial amounts of LH and FSH. This surge in LH leads to ovulation, which is the release of the oocyte from the dominant follicle and marks the end of the follicular phase.
Following ovulation, the remnant of the follicle undergoes luteinization due to the LH surge, transforming it into the corpus luteum, which secretes progesterone. This hormone is vital for successfully establishing and maintaining a pregnancy and prompts the switch to the secretory phase in the uterus, prepping the endometrial lining for potential implantation.
Given the accurate description of these hormonal changes and their role in the menstrual cycle, the correct option for the student's question is a. true.