Question

There are two meiotic events that contribute to genetic diversity in a population (random chromosomes alignment and crossing over)

After meiosis has increased diversity, there is one more place that genetic diversity can increase even further. This place is the events leading to fertilization. Explain what happens during this stage of reproduction that increases the genetic diversity in a population even more than meiosis alone

Answer 1

The genetic variation are arises at three stages:

* crossing over at pachytene stage of prophase 2 of meiosis 1

*random chromosomes alignment at anaphase 1 of meiosis 1.

*Random fusion of gametee during fertilisation. Because there are formed different combination of gametes fusion occurs at this stage. This is known as random fusion of gametes.

let understand it with example:

If there are found two types of gametes formation occurs by each parent, then the possible fusion of gametes produces 3 genotype in offspring.

let each parent produces A and a gametes, then following types of individuals are formed.

punnet square:

Gametes	A	a
A	AA	Aa
a	Aa	aa

Similarly with increase in number of gametes produced by the parents, there are found more number of genetic variation bearing offspring because of random fusion of gametes. That's why the fertilisation even leads to increase in genetic diversity in the further generation.