Question

Tools Add-ons Help Accessibility All changes saved in Drive text Times New.. 11 BI U A G - E 15 Problems, 25 points @ 5 points each unless indicated otherwise. Show your work to get full or partial credit. 1. Examine each pedigree shown (a-c). The shaded square/circle shows an inherited phenotype. For each (a, b, c), write a sentence or two that indicates whether it is (or is not) consistent with X-linked recessive inheritance. If you decide the pedigree IS consistent, for full credit you must prove this by setting up a Punnett square or a forked line diagram. (6 pts) ooooo

Answer 1

a) is consistent with the X-linked recessive inheritance.

let the alleles be XD-normal allele, Xd- mutated allele.

the affected male is XdY and the phenotypically normal female is XDXd

XdY * XDXd

	XD	Xd
Xd	XDXd ( carrier female, phenotypically normal)	XdXd ( affected female)
Y	XDY ( normal male)	XdY ( affected male)

here affected female, normal female and normal male are there in the progeny so this pedigree is consistent with the X-linked recessive inheritance if the genotype of the mother is XDXd.

b) this pedigree is consistent with the X-linked recessive inheritance.

the female is a carrier XDXd and male is XDY

XDXd * XDY

	XD	Xd
XD	XDXD ( normal female)	XDXd ( carrier female, phenotypically normal)
Y	XDY ( normal male)	XdY ( affected male)

affected and normal boys and normal girls are possible, in the pedigree, there are both affected and normal boys and normal girls.

c) this pedigree is not consistent with the X-linked recessive inheritance, here mother is affected, if this was sex-linked recessive inheritance her genotype is XdXd, and the genotype of the father is XDY

XDY * XdXd

	Xd	Xd
XD	XDXd (carrier, phenotypically normal female)	XDXd ( carrier, phenotypically normal female)
Y	XdY ( affected male)	XdY ( affected male)

if this was sex-linked recessive inheritance all the boys will be affected, but here there are normal boys so this is not sex-linked recessive inheritance.