Question

3. Colour-blindness is a X-linked, recessive trait. If a normal-sighted woman, whose father was colour-blind, marries a colour-blind man, what is the probability that they will have a son who is colour-blind? (use the letter "B") 4. A man and woman, both of normal vision, have: 1) a colour-blind son (#1) who has a daughter of normal vision 2) a daughter (#1) of normal vision who has one colour-blind son and one normal vision son 3) another daughter (W2) of normal vision who has five sons, all with normal vision What are the probable genotypes of the grandparents (man and woman), the children (son #1, daughters #1 & 2) and the grandchildren?

Answer 1

er was woman is normal sighted but father, colour blind so her genotype should be x B x beaue father was 1 x By but woman is normal sighted I so one x chromosome us normal So woman should be x B x Man is color delind so genotype is x By so genoty bes are Woman man - gameto Now Check genotype of children to X Y xo xQy B xoy XI XX XY The genotype of son's xoy and XY I so out of 2 son's one 1 will be color blind so probability cs Scanned with Te x lo o 50% CamScanner

There is 50% progency to be probability color beidd. of male I Man ut Man's I woman's and woman have normal vision progeny has color blindners so genotype should be - XY genotype should be - XB X UA color blind son of the above couple will have the genotype Xoy Daughter has normal vision so his I drughter can be XBX or XX (first couple's grandchildren] Daughter C# 1) of normal vision has 1 1 normal and 1 color blind son. Son will get X chromesome from mother as one son is normal and one color blind so the mother should be X X . If father is normal he will have genotype XY Now make punnett square X Y XL XBXLXByt 2 sons one normed X XX XY f one Colorblind I can these are genotypes of first couples grandchilchen I Saleelle

You know e x chromesome blendres in Daughter number 2 has all so with normal vision. You that Son will get one x chrom from mother and color blendnen x linked recessive trest but it color blindness allele is on x Chromosome in man, the man will be color blind because there in only one copy of X Chrome some - the genes of X chromesome will be expressed. So mother should be normal and shouldn't be a carrier. So mother's genoty be will be XX. chrome some so Now suppose This woman married la normal man XY the progeny will be - X Y - X L XXL XY17 normal sons XX Txy - بلين x x - a will Suppose colorblind be this XX man X oy woman mories the progeny xoxl YB all song sqanned with CamScanner normal

A. So all her son's will have genety pe XY ... Irrespective of whether the woman is married to a color blind on normal man... So in this case first couples groindchildren will be xy. 1* Progeny of first couple Vi tx By Rxy T 1 normal and 1 1 carrier (XB x) normel. i deceg hiter color blind and one iii son non carrier .... 2* - Coler blind son X BY ... Suppose he married nermal temele XX Look at the progeny I X HXBX F xoxt y | XY XY Both daughtons are carrier but o not color blind amScanner in banned with . .

w suppose blind celor he marries woman a carrier (x B x) progeny will be 1 у TB x B x B x хвуху and one one daughter color will be normal blind. Es-Seemned CamScanner