Fertilization

What is the importance of amphimixis?

Rashmi gave birth to three girls. Her mother-in-law blamed her for giving birth to girls. However, as we know, ova (eggs) are only of one type containing 22+X chromosomes, but sperms are of two types: one type of sperms contain 22+X chromosomes and another type of sperms contain 22+Y chromosomes. When ovum and sperm with 22+Y chromosomes are fused, a male child is formed and when ovum and sperm with 22+X chromosomes are fused, a girl child is produced.

Read the above passage and answer the following question:

In your opinion, who is responsible for the female child (mother or father)?

The human zygote has _____ pairs of chromosomes. (Answer in number)

Significances of fertilisation are

All copulation or coitus leads to pregnancy.

The penetration of the vagina by the penis is called vaginal coitus.

Give the significance of fertilisation.

What is amphimixis?

During the process of fertilization, the sequence of layers crossed by sperm are:

The minimum number of meiotic divisions required to form fraternal twins are

Read the following statements and choose the correct option.

I. hCG prevents the regression of corpus luteum if fertilization takes place.

II. Falling levels of LH cause degeneration of corpus luteum in a regular menstrual cycle.

The number of ova produced by a female who gave birth to identical twins and another who gave birth to fraternal twins are, respectively,

Find out the incorrect statement.

In human during fertilization a sperm firstly comes in contact with which layer of ovum

In macro and telolecithal eggs site of amphimixis lies in the

In human beings, normally in which one of the following parts, does the sperm fertilize the ovum?

Fertilization involves

Fertilization of ovum by the sperm takes place in:

Grey crescent is the area

Sex is determined in human beings