You might think differently but this is my answer.
The sperm cell's job is to fertilise an egg[ovum]. Its body helps it do so because of its streamlined head, small body and long tail. The tail provides the sperm movement, meaning it can swim to the egg. The streamlined head helps it move faster. And its small body is just a small body. Here is a picture of the sperm cell.
A sperm cell's job is to penetrate the woman's egg and keep it fertilized so the cells multiply to make a baby. They look somewhat similar to a tadpole and they are about 40 microns long. The period at the end of this sentence is about 615 microns long.
And...... I want to know for my self some information!!!
Thats all I know, may be its wrong!