Question

In pea plants the pod texture is hereditary. John crossed a pea plant that produces wrinkle pod, with another pea plant that makes smooth pod, He found that all 1000 F1 pea plants produce smooth pod. What do you know about the traits of the pod texture gene?

Answer 1

Just as in the flowers, fruits, and seeds, the pod texture is also controlled by genes. The pods are of two types inflated or smooth. The law of dominance/ recessive pattern is seen in its inheritance, where the smooth pods are dominant.

In the above experiment, it seems that the plants with smooth pods are pure breeding with both the genes for smooth pod [ let us denote the genes by SS]. The plants with wrinkled pods are pure breeding too [ let us denote the genes by ss] because even if they had one S gene they would produce smooth pods. So, we can safely assume that the genotype of these plants must be 'ss'.

When these two plants are interbred, all the seeds will have the genotype 'Ss' [having inherited one gene from each plant].

This is why all the plants in F1 generation have smooth pods but they their genetic composition is 'Ss'.