Question

Vanessa and zac are married. vanessa's maternal great grandma has rare disease caused by recessive allele. zac's brother also has the rare disease. no one else in both families have the disease and those married into vanessa's family do not come from high risk of having the recessive disease.
show work:
1.if zac and vanessa have 2 kids, whats the chance that ONLY ONE will have disease?
2. zac and vanessa had a girl with the disease, whats the chance their next kid will be UNAFFECTED girl?

Answer 1

Given data Vanessa and zac are married. Vanessa's maternal great grandma has rare disease caused by recessive allele Zac's brother also has the rare disease. No one else in both families have the disease and those married into vanessa's family do not come from high risk of having the recesive disease. The above given data is sufficient to analyze the question as tollaot; - Vanessa's maternal great mother grand mother only have a rare recessive disease. Altee that no one is affected with that disease, not vanessa's grandma & not her mother. That mean the trail skipped the generation. And this skipping of generation of talt is only found in Autosomal recesine disease. so the given trait is Autosomal Recessive We can make a chart of Pedigree of Vanessa's & Lae's family as follows, toltoo Key points :- A A = No disease Great Grandma (aa) AA bal o nda = Disease! Aa Disease Grandma (Aa) LAA (unaftated) caries I TA I Mother + Aa aa I Generation - Аа Zac Vaneesa Zac's brother diseased. affected Carrier Carrier

the chance 1 17 Lac that and vanessa have a kids , what only one will have disease ? =) As we know the alleles for trait, for Zac and Vanessa, so we can represent lit as follace, V slovo no la Vanessa na Zae te beror sol 2 for a trait He l's also carries Vanessa és will Carrier of trait therefore having Aa.. aralleles. To me I they have onlap A ka aa Aatic skidos no 0 Disease o cazie care VLAS s. if Jax & vanessa have 2 kide, there is o 257. Chance with each popregnancy of having a child affected by the disease 2) Zac and Vaneesa had a girl with the disease, whats the chance their next kid will be unaffected giet? - We can use a small punett's square table to justify our arismer (0) vanessa A Aa zac. los A АА Aa a na ga Diseased Cattected girl According to the above table, if a first as diseaged caa) then, Blatte

an. The chance with each pregnancy of having un affected child gist is 50%