Question

Which of the following is not a function of progesterone?
A. Gestation
B. Stimulation of mammary gland
C. Inhibition of ovulation
D. Uterine growth and development

Answer 1

Progesterone is a hormone which is secreted by corpus luteum under the control of luteinizing hormone during the second half of the menstrual cycle and under human gonadotropin hormone during pregnancy of women.

Complete answer:
Progesterone is a steroid hormone which belongs to the group of hormones called progestogens. It is mainly secreted by the ovaries in the corpus luteum, during the second half cycle of menstrual cycle. Adrenal gland and placenta, formed during pregnancy to provide nutrition to the embryo, can also produce progesterone.
During menstrual cycle when levels of luteinizing hormone increases, it leads to the ovulation that is, release of ovum (female gamete). After the release of egg, corpus luteum forms and starts secreting progesterone. Here, Progesterone helps in preparing the body ready for the pregnancy by stimulating glandular development and by producing new blood vessels. And hence, implantation of zygote can be done.
During pregnancy, corpus luteum is not broken and it continues to produce progesterone. Thus, it develops blood vessels and stimulates them to provide nutrition to growing embryos. After the formation of placenta, it becomes the primary producer for progesterone and the level of progesterone remains high throughout the pregnancy. And in later stages, progesterone helps in triggering lactation.
Thus, from the above discussion we can conclude that progesterone hormone is not involved in the stimulation of the mammary gland.

Thus, option ‘B’ is correct.

Note:
If eggs do not get fertilized the corpus luteum breaks down and decreases the levels of progesterone and causes the beginning of menstrual periods. And in males, progesterone is also produced from adrenal gland and it works in development of sperm which is male gamete.