Question

10. In man, muscular dystrophy is a condition in which the muscles waste away during early life and may result in a shorter life-expectancy. It is due to a sex-linked, recessive gene. A certain couple has five children - three boys (ages lyr, 3yrs, and 10yrs old) and two girls (ages 5yrs and 7yrs old). The oldest boy shows the symptoms of this disease. You are their family physician and they come to you for advice. What would you tell them about the chances of their other children developing the disease? 11. In man, optic atrophy (a type of blindness due to a defective optic nerve) is controlled by a sex- linked, recessive gene. Aniridia (a type of blindness due to the absence of the iris) is controlled by a dominant autosomal (not sex-linked) gene. A woman who is blind from optic atrophy marries a man who is blind from aniridia, whose father was not blind. What types of children can they have? (use the letter "b" for optic atrophy and the letter "A" for aniridia) X (HINT: a DIHYBRID CROSS must be done) please show me the answer with dihybro

Answer 1

- . LL. AINSMAllialas Page 1 11 Answer As per the given data- consider female to be not a carrier Then, i male. Female YX XX (Upper cose to be normal and lover case defectel) E Y X X X Gamete yx yx xx xx ffyrst generation Call females will be . : Carriers and makes are normal) | E considering female to be carried Then, male Female YX , xx Copper case to be normal and lover case detecteds . Y X X X Gamate 111111iY

Page 2 yx yx xx xx first generation (50% female will be carriers and 50% diseased: mcase aos males 50% diseased and 50% normal). Andola man's father was not blind and autosomal dominant disease then it's genotype must be male Female Aa Yx 13 aa xbxb AY IdXB axb, axb Grametes Aa Yxb, ad YXB, Aa XB Xb, da xBxb (Post generatin Inference: 50% male will be blind by both types 1 Aayxb. 50% males will be normal, 50% women will be blind by ampdria along with carrier of optie atoopy 50% clomen will be carrier for optic atospy only (no ampdora dominant gene).

page-3 O Answer! muscular dystrophy as an X-linked recessive geme - E-tic disorder Generally the males have the Wigher chance or getting Enfected because they have only one copy oor x'-chromosome , Inherited from thes mothers.on the other hand females have two ! - copies, the other inherited from their fathers, so in a family with five children (3 boys and 2 gBols) out of which the eldest boy has alseady shown symptoms of getting affected, - since it is a rate disorder and also the chance of getting aftected in females is less it can said that it is very less likely that another child also develop this dare disease. NVMITT please give with this a positive vote, will you satisfy Explenation, CY11