|
 | 23 chromosomes! | |
|
| When the mother's egg and the father's sperm unite, each contributes | |
|
|
|
|
|
|
| they are the same age and usually raised in similar environments, but they do not have the same genetic code. | |
|
| annddd... researchers find the study of fraternal twins important, because... | |
|
|
|
|
|
|
| group of variation in a trait than can be explained by genetics. | |
|
| heritability refers to the percentage of.. | |
|
|
|
|
|
