K.C.S.E Biology Q & A - MODEL 2001PP1QN14
Tallness in pea plants is due to a dominant gene Two tall pea plants were crossed and their F1 generation were in the ratio of 3 tall: 1 short. Using letter T to represents the gene for tallness and t for shortness give the
(a) (i) genotype of the parents
(ii) Gamete of the parents
(iii) Genotype ratio of the F1 generation
(b) What is meant by the term testcross in genetic studies?
(a) (i) Tt, Tt
(ii) Tt and Tt
(iii) 1TT; 2Tt; 1tt/ 1 tall homozygous; 2 tall heterozygous
1 short homozygous 1:2:1
(b) Crossing a homozygous recessive organism with an organism which shows dominant characteristics.