Meiosis is the process by which the number of chromosomes is reduced by half to form sex cells--sperm and eggs. Meiosis can be broken up into 4 main parts: Before Meiosis, Meiosis 1, Meiosis 2, and End of Meiosis.
Before Meiosis:
Before meiosis begins, every chromosome in the parent cell is copied. Centromeres hold the two chromatids together.
Meiosis 1:
First, the pairs of chromosomes line up in the center of the cell. Next, the pairs separate and move to opposite ends of the cell. Then, two cells form, each with half the number of chromosomes. Each chromosome still has two chromatids. Like if you were to split a hard-boiled egg in half, and the yolk is the chromosome pairs and the white is the cell. To get 2 different parts of the egg, you split the egg in half, by breaking the egg in half with half the white and half the yolk on either side.
Meiosis 2:
First, the chromosomes with their two chromatids move to the center of the cell. Then, the centromeres split, and the chromatids separate. Single chromosomes move to opposite ends of the cell. This is where you would divide the egg halfs into 4 quarters, each with equal amounts of yolk and white.
End of Meiosis:
At the end of meiosis, four sex cells have been produced. Each cell has only half the number of chromosomes that the parent cell had at the beginning of meiosis. Each cell has only one chromosome from each original pair. You now have 4 identical pieces of egg, each with some of the egg yolk in it.
Meiosis can also be shown by a punnett square:
The sperm goes on top, and the eggs go on the side. Then you cross multiply the alleles of the sperm with that of the eggs to come up with the possible crosses of those two organisms.
You may be asking: Why is meiosis even important? Meiosis is important because if meiosis did not happen, then we would not be able to reproduce.
Before Meiosis:
Before meiosis begins, every chromosome in the parent cell is copied. Centromeres hold the two chromatids together.
Meiosis 1:
First, the pairs of chromosomes line up in the center of the cell. Next, the pairs separate and move to opposite ends of the cell. Then, two cells form, each with half the number of chromosomes. Each chromosome still has two chromatids. Like if you were to split a hard-boiled egg in half, and the yolk is the chromosome pairs and the white is the cell. To get 2 different parts of the egg, you split the egg in half, by breaking the egg in half with half the white and half the yolk on either side.
Meiosis 2:
First, the chromosomes with their two chromatids move to the center of the cell. Then, the centromeres split, and the chromatids separate. Single chromosomes move to opposite ends of the cell. This is where you would divide the egg halfs into 4 quarters, each with equal amounts of yolk and white.
End of Meiosis:
At the end of meiosis, four sex cells have been produced. Each cell has only half the number of chromosomes that the parent cell had at the beginning of meiosis. Each cell has only one chromosome from each original pair. You now have 4 identical pieces of egg, each with some of the egg yolk in it.
Meiosis can also be shown by a punnett square:
The sperm goes on top, and the eggs go on the side. Then you cross multiply the alleles of the sperm with that of the eggs to come up with the possible crosses of those two organisms.
You may be asking: Why is meiosis even important? Meiosis is important because if meiosis did not happen, then we would not be able to reproduce.