Mutations can be categorized based on the kind of effect they have on an organism. Blue eyes in humans are a result of a mutation in the OCA2 gene, which controls the production of pigment melanin in the iris.
This mutation is an example of a neutral mutation. Such mutations have no effect on an organism’s survival.
<span>There are four possible phenotypes with a dihybrid testcross. The 1:1:1:1 ratio means that there is an equal chance of any of the four expected phenotypes in the offspring.</span>