Also located on the X chromosome of a cal is a gene hat code

Also located on the X chromosome of a cal is a gene (hat codes for deafness. This gene is recessive. A black female cat that is heterozygous for deafness (Dd) is crossed with a yellow male cat that is not deaf. Show the cross. What are the phenotypes of the offspring and in what proportion. In mice, the spinning behavior is caused by a dominant gene that effects the mouse\'s equilibrium. This gene is lethal if two alleles are present. Two \"spinning mice\" are mated together. Show the cross. What are the phenotypes of the offspring and in what proportion. (Be sure to not count any offspring that don\'t survive.) A nurse at a hospital removed the wrist tags of three babies in the maternity ward. She needs to figure out which baby belongs to which parents, so she checks their blood types. Using the chart below, match the baby to its correct parents. Show the crosses to prove your choices.

Solution

14.

Female cat genotype : X^DX^d

Male cat genotype : X^DY

X^DX^d x X^DY

The phenotypes of the offspring are:

normal female cat = 2

normal male cat = 1

deaf male cat = 1

Proportion = 2 : 1: 1

	XD	Xd
XD	XDXD (normal female cat)	XDXd (carrier but normal female cat)
Y	XDY (normal male cat)	XdY (deaf male cat)