genetics........

Question

Assume that brown eyes (B) is dominant to blue eyes (b) and rounded chin (R) is dominant to pointy chin (r). George has brown eyes and a pointy chin. Mary has blue eyes and a rounded chin. George’s mother had blue eyes. Mary’s father had a pointy chin. a) What are the genotypes of George and Mary? b) What is the chance that George and Mary will have a kid with brown eyes and a rounded chin? c) What is the chance that George and Mary will have a kid with blue eyes and a rounded chin? d) Does George’s father have brown or blue eyes? e) What types of chins do George’s parents have? f) Does Mary’s mother have a rounded or pointy chingenetics

Answer 1

a.

George's geneotype Bbrr possible gamates are Br, Br, br, br

Mary's geneotype bbRr possible gamates are bR, br, bR, br

 

b. requires a punnet square

 

              Br            Br                br           br

bR      BbRr            BbRr            bbRr       bbRr

 

br      Bbrr             BbRr            bbrr        bbrr

 

bR      BbRr            BbRr           bbRr        bbRr

 

br      Bbrr            BbRr            bbrr         bbrr                       then tallie up different offspring.

 

BbRr 4  25% chance brown eyes and round chin

Bbrr 4  25% chance brown eyes and pointy chin

bbRr 4  25% chance blue eyes and round chin

bbrr  4  25% chance blue eyes and pointy chin

 

Georges father has brown eyes that is where is dominate gene came from.

Both his parents have recessive gene for pointy chins

Mary's mother has a round chin.