In another example of Mendel's independent assortment principle, a test cross between a heterozygous BbEe fly and a homozygous bbee fly will yield offspring with only four possible genotypes (BbEe ...

We also look at how a heterozygous mutation differs from a homozygous mutation. A note about sex and gender. ... In females, each parent has an X chromosome with the same atypical gene.

Scientists fully sequence the Y chromosome for the first time, uncovering information that could have implications for the study of male infertility and other issues.