Dependent variable. Hope it helps.
Yes. It can reproduce in a living cell
Both parents are normal. But, some of the kids have the disease. This indicates that the parents are heterozygous for the disease (let's use Dd). They are phenotypically fine because D is normal. But we know they must both carry the diseased d allele because their kids have the disease.
If you cross Dd x Dd you get DD, Dd, Dd and dd as the possible outcomes. But because each time they have a child they roll the dice as to which of the 4 above happens, they were unlucky as 3 of those times they got dd for their child...so 3 of them have the disease (and are dd). One is phenotypically normal but could still be Dd or DD.
It acts as an accessory pigment! Hope this helps! Also sorry that it took 11 hrs. for people to answer! =)
