Answer to Question #244759 in Genetics for Tumzaza

Question

In peas, a gene for tall plants (T) is dominant over its allele for short plants (t). The gene for smooth peas (S) is dominant over its allele for wrinkled peas (s). The genes are not linked. Determine both phenotypic and genotypic ratios for the results of each of the following crosses:

3.4. heterozygous tall homozygous smooth x short wrinkled.                 [26 marks]

Answer 1

Genotypic ratio:1 TTSS: 2 TTSs: 2 TtSS: 1 TTss: 4 TtSs: 2 Ttss: 1 ttSS: 2 ttSs: 1 ttss

9 possible genotypes

1 TTSS: 2 TTSs: 2 TtSS: 1 TTss: 4 TtSs: 2 Ttss: 1 ttSS: 2 ttSs: 1 ttss

Phenotypic ratio:

9 Tall and smooth: 3 Tall and wrinkled: 3 Short and smooth: 1 Short and wrinkled