Question

In sexual reproduction, (a) Name the cell division which helps to get the DNA amount to its half in germ cells. After

fertilization what is the DNA amount in the zygote ? What is the use of this process?

b) Differentiate between male and the female germ cells in human beings .​

Answer 1

Answer:

Fertilized florets fixed 19.5 hours after pollination (Figs. 1b and 1e) contained either zygotes at various stages of mitosis or, in one case, a 2-celled proembryo in which both cells were at G1 stage. The mean estimated DNA content of the 5 zygotes at mitosis was 4.60C and individual values ranged from 3.83 to 5.71C.The zygote normally contains two complete sets of 23 chromosomes, and two copies of every gene .

Explanation:

Male Germ cell Female Germ cell

1. Produced by male reproductive organ (testes in animals, anther in plants 2. Usually smaller in size and motile. 1. produced by female reproductive organ (ovary in animals and plants) 2. Usually larger in size and stores food.