Question

What would be the ratio of chromosome number between an egg and its zygote? How is the sperm genetically different from the egg?

Answer 1

The egg is produced through meiosis so it contains half the number of chromosomes than a zygote. So, the ratio of chromosome number between an egg and zygote is 1:2. Human males have two types of sex chromosomes - X and Y whereas human females have two X chromosomes. So, the sperms contain either X or Y chromosome whereas eggs contain only X chromosome leading to genetic difference between them.