Question

Estrogen is secreted by:

• A. Corpus luteum
• B. Membrane granulosa of Graafian follicle
• C. Pituitary gland
• D. Germinal epithelium

Hint:

Remember: Graafian follicle (before ovulation) → Estrogen; Corpus luteum (after ovulation) → Progesterone.

Answer 1

The Correct Option is B

Step 1: Estrogen is the primary female sex hormone responsible for secondary sexual characteristics and regulation of the menstrual cycle.
Step 2: During the follicular phase of the menstrual cycle, developing follicles grow and mature.
Step 3: The inner lining of the Graafian follicle, called the **membrane granulosa**, contains cells that secrete estrogen.
Step 4: These granulosa cells convert androgens (from the theca interna) to estrogen using the enzyme aromatase.
Step 5: The corpus luteum secretes progesterone after ovulation, not estrogen.
\[ \Rightarrow \text{Hence, the correct answer is } \boxed{\text{(B) Membrane granulosa of Graafian follicle}}. \]