The ratio of chromosome number between an egg and its zygote is 1:2. Sperms contain either an X or a Y chromosome, while eggs always contain an X chromosome, leading to genetic differences between them.
Here’s a more detailed explanation:
Egg and Sperm Chromosome Number:
Both egg and sperm cells are haploid, meaning they contain half the total number of chromosomes of a regular body cell. In humans, this is 23 chromosomes in each gamete.
Zygote Chromosome Number:
When an egg and sperm fuse during fertilization, they form a zygote, which is diploid. This means it contains the full set of chromosomes, 46 in humans, which is 23 pairs.
Chromosome Number Ratio:
The ratio of chromosome number between the egg (haploid) and the zygote (diploid) is therefore 1:2.
Sperm and Egg Genetic Differences:
The key genetic difference between sperm and egg lies in their sex chromosomes. Sperms can carry either an X or a Y chromosome, while eggs always carry an X chromosome. This difference determines the sex of the offspring. If a sperm carrying a Y chromosome fertilizes an egg, the resulting zygote will be male (XY). If a sperm carrying an X chromosome fertilizes an egg, the zygote will be female (XX).