reproduction

VP-#4
Sex does not mean the same thing as reproduction. Girls have a set number, 1 egg each month. Boys only get sperm cells when they hit puberty. The body will stop releasing eggs when the zygote forms. For fish all the time they fertilize the eggs outside the body. Fish do not have to have sex. The boy fish let all their sperm go at any time. Sperm cell has 50% and egg has 50% of chromosomes. there are 4 homologous pairs which is really 8 chromosomes. Homologous pairs are 2 chromosomes needed to code for the same trait.

Here is a link for a picture of a sperm cell:
http://saintzy.files.wordpress.com/2007/03/sperm-cell.jpg


Sperm cells are made by using meiosis.


Here is a link for a picture of meiosis:
http://dbscience3.wikispaces.com/file/view/meiosis-big.gif/63281204/meiosis-big.gif


VP-#4