Could haemochromatosis also be caused by someone's environment?

The organelle pictured is found in cells of and is theorized to have once been an independent organism.

How does the study of genetic disorders such as pku biologists understand normal alleles?

Dna. we have heard that we are a product of our dna. but where is it? how do we "get" our dna? it is passed to us, from our parents, but in what form? several vocabulary words associated with inheritance are used interchangeably and sometimes, incorrectly. let's see if you can clear this up for someone just learning about inheritance and cell structure.