What happens during conception?

Explanation:

during fertilisation the sperms are drawn up by a suction through the cervix into the uterus where they swim upto the oviduct using their tails although the sperms are millions only one will fertilise the ovum. as the ovum moves down the oviduct, it releases chemical substances which have to be neutralised by those produced by the acrosome before the sperm penetrates the ovum. when the sperm comes into contact with the egg the acrosome bursts open and releases the lytic enzymes which dissolve the egg membranes. Then the acrosome then turns inside out forming a fine filament that is used to penetrate the egg. Hence the head of the sperm enters the ovum, the tail is left outside the egg. the vitelline membrane undergoes a change which stops any other sperm from entering the ovum. once in the cytoplasm the head bursts to release the male nucleus then fuses with the female nucleus to form a diploid zygote

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: