Question

Progesterone present in the contraceptive pill is meant for
(a) Checking ovulation
(b) Preventing fertilization
(c ) Preventing implantation of the zygote
(d) Presenting cleavage

Answer 1

Hint: A contraceptive pill is a birth control pill that is enriched with two main female hormones, one of which is progesterone. Progesterone present in the contraceptive pill prevents the process of fusion of male and female gametes by not letting the ovum exit the ovary.

Complete answer:
A contraceptive pill is an oral pill that is made up of the combination of two hormones which are estrogen and progesterone. The hormones produced in our body i.e follicle-stimulating hormone and luteinizing hormone helps in ovulation and egg development. The progesterone present in the contraceptives prevent the release of FSH and LH and thus prevents ovulation.

Additional Information:
-By preventing ovulation, progesterone terminates the occurrence of the next steps which are fertilization, cleavage, and implantation of the zygote.
-In normal circumstances, ovulation is followed by fertilization.
-Cleavage transforms the zygote into a morula. It is characterized by a solid mass of cells with 16-32 cells.
-This will lead to a blastula stage or a hollow mass of cells. A fluid-filled cavity inside the ball of cells is called the blastocoel surrounded by an outer layer ‘trophoblast’ and an inner layer ‘inner cell mass.’
-The trophoblast layer extends into the endometrial lining of the uterus by breaking down the molecules of the endometrium.
-This is then followed by the gastrulation stage wherein the three germ layers are originated by the rearrangement of cells into endoderm, mesoderm, and ectoderm. And this ball of cells is known as gastrula.
-After implantation, the placenta is formed.

So, the correct answer is ‘Checking ovulation.’

Note: The placenta acts as a barrier between the fetus and the mother. Although the blood of the fetus and mother do not mix or blend, the placenta acts as an ultrafilter where soluble nutrients, minerals, hormones, antibodies, can cross over and pass onto the fetus. It also helps in the exchange of gases between the two as well as the elimination of nitrogenous wastes from the fetus.