Question

When both ovaries are removed from the rat then which hormone is decreased in blood?

• A. Prolactin
• B. Oxytocin
• C. Gonadotropin-releasing factor
• D. Estrogen

Answer 1

The correct option is D

Estrogen

The correct option is D.

Explanation of the correct option:

1. Ovaries secrete estrogen.
2. The ovaries are specialized in the production of ova (eggs), the transport of egg cells to the fertilization site, provision of a suitable environment for the growth of embryos &, at the appropriate time, transfer of offspring outside the body (birth).
3. After birth, the reproductive system provides food for offspring and produces female sex hormones.
4. The vagina, ovaries, and mammary glands are also the major structures of the system of the female rat.
5. The ovaries preserve the fitness of the female reproductive system.
6. Two primary hormones are secreted by the ovaries: estrogen and progesterone.
7. In puberty of females, estrogen is responsible for the emergence of secondary sexual characteristics & the maturation and maintenance of reproductive organs in their mature functional state.
8. Progesterone prepares the uterus for pregnancy and lactation.
9. Since the ovaries secrete estrogen, the estrogen hormone in the blood decreases when the ovaries are withdrawn.
10. Thus, the removal of ovaries from the rat causes the decrease of the hormone estrogen in its body.

Explanation of the incorrect options:

Option A: Prolactin is the pituitary hormone.

Option B: Oxytocin is the pituitary hormone and the gonadotropin-releasing hormone is generally secreted by the hypothalamus.

Option C: Gonadotropin-releasing hormone is generally secreted by the hypothalamus.

Final answer: When both ovaries are removed from the rat then estrogen is decreased in the blood.