Question

During pregnancy the production of ova in ovary is prevented by
A)Estrogen
B)Relaxin
C)Progesterone
D)Prolactin

Answer 1

There are many hormones which are produced by the female during pregnancy. During pregnancy, the ovulation does not take place. It is prevented by the action of a hormone which is produced by corpus luteum. This hormone is responsible for release of ova or egg.

Complete answer:
To solve this question, we must know about the pregnancy hormone.
The estrogen and progesterone are called the pregnancy hormone. A female produces more estrogen during pregnancy. It enables the uterus and placenta to develop and vascularise.
Progesterone is the main hormone responsible for the ovulation. It is secreted by corpus luteum. It plays an important role to prevent the release of eggs till pregnancy is terminated.

After implantation, placenta produces progesterone so that the uterus does not contract till child birth.
Relaxin – It is the hormone required for childbirth. It is secreted by the placenta and causes dilation of the cervix. Also prepares the uterus for labour.
Prolactin- Prolactin is produced by the pituitary gland. It stimulates the growth and development of the breast to facilitate milk production after child birth.

Hence, the correct answer is option (C)

Note: The progesterone also helps in preventing muscular contraction in the fallopian tube. Progesterone also stimulates the breast to produce milk. The low progesterone levels cause infertility, irregular menstrual cycles, weight gain, hot flashes. The high level of progesterone causes headache, change in heart rate, coughing, depression, confusion, difficulty in breathing.