What is the meaning of the word DIPLOID?

1 Answer

It means that nucleus of an eukaryotic cell has 2 copies of each chromosome. All the non-gamete cells in your body are diploid.

Explanation:

During sexual reproduction, a sperm cell (male gamete ) fuses with an egg (female gamete) to form a zygote. The gamete cells of human, each have 23 chromosomes, and when they come together the resulting zygote has 46 chromosomes (2 of each kind, i.e. 23 pair).

So, you'd say that the zygote is diploid, and the individual gametes are haploid.

Handy way to remember:
- Diploid => "Di" => 2.
- Haploid => "Ha" => Half (of 2) => 1.

Not very sophisticated, but hopefully that will help it stick in your head.

Diploid number (=2n) may vary with species: for example cell of a pea plant will have 7 pair or 14 while in each cell of dog, there will be 39 pair or 78 (please do not consider germ cells).

https://image.slidesharecdn.com/chromosome-151102144919-lva1-app6891/95/chromosome-32-638.jpg?cb=1446475832

Here are some excellent videos to help you grasp this concept better:
"Diploid vs. Haploid Cells" - Bozeman Science
"Fertilization terminology: gametes, zygotes, haploid, diploid" - Khan Academy

Hope that helps :)