1. Mutations can be caused in 3 ways, one way there can be too many codons, second they can have too little, and last they can be out of order. These result in good or bad phenotype variations.

2. Gametes and germ cells Gametes are sex cells. Germ cells are just another name for sex cells. These cells help in cellular reproduction and only divide the sex cells (sperm/egg).

3. The cross over of DNA. The cross over of DNA is when the males DNA and the females split in half and then each half combines and makes the possibility of infinite phenotypic variations that can take place.

4. Sexual reproduction Sexual reproduction is the leading in variations made to organisms. When the cells and DNA go through meiosis millions and millions of variations can be made.

5. variations During meiosis there are 2 23 possible variations from one gamete, but if the two gametes from the male and the female there are infinite amount of phenotypic variations to the offspring.