The 'Hormone Luteinizing Hormone' (LH) is secreted by the anterior pituitary. In females, the mid-cycle surge of LH directly triggers: MCQ with Answer and Explanation
The 'Hormone Luteinizing Hormone' (LH) is secreted by the anterior pituitary. In females, the mid-cycle surge of LH directly triggers:
A. The growth of ovarian follicles
B. The thickening of the uterine lining
C. Menstruation
D. Ovulation and the formation of the corpus luteum
Answer: Option D
Solution (By JKSSB Mock Tests)
Luteinizing Hormone (LH) is a gonadotropin secreted by the gonadotroph cells of the anterior pituitary. In females, during the late follicular phase, rising estrogen levels exert positive feedback on the pituitary, causing a massive, sudden surge of LH (the LH surge). This surge directly triggers ovulation (the rupture of the mature Graafian follicle and release of the secondary oocyte) and subsequently stimulates the remaining follicular cells to transform into the corpus luteum, which secretes progesterone.
Consider statements about cell biology: 1. The cell membrane is selectively permeable. 2. The nucleus contains genetic material. 3. Mitochondria are the site of photosynthesis. Which are correct?
Explanation:
The cell membrane (plasma membrane) is selectively permeable, regulating the passage of substances in and out of the cell to maintain internal homeostasis. The nucleus is the membrane-bound organelle that houses the cell's genetic material (DNA) organized into chromosomes, directing cellular activities. Mitochondria are the site of aerobic cellular respiration and ATP production; chloroplasts are the organelles where photosynthesis occurs in plant cells. Thus, statements 1 and 2 are correct.
Explanation:
The soft palate, including the uvula, elevates during swallowing to close off the nasopharynx, preventing food from entering the nasal passages. The epiglottis closes the larynx, the tongue pushes food.
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