Mendel blended his knowledge of Science and mathematics to keep the count of the individuals exhibiting a particular trait in each generation. He observed a number of contrasting visible characters controlled in pea plants in a field. He conducted many experiments to arrive at the laws of inheritance.

(a) What do the $F_1$ progeny of tall plants with round seeds and short plants with wrinkled seeds look like?

(b) Name the recessive traits in above case.

(c) Mention the type of the new combinations of plants obtained in $F_2$ progeny along with their ratio, if $F_1$ progeny was allowed to self pollinate.

The dihybrid cross ratio of $9:3:3:1$ is a mathematical consequence of two independent monohybrid crosses multiplying together: $(3 \text{ Tall} : 1 \text{ Short}) \times (3 \text{ Round} : 1 \text{ Wrinkled}) = 9 \text{ Tall-Round} : 3 \text{ Tall-Wrinkled} : 3 \text{ Short-Round} : 1 \text{ Short-Wrinkled}$. When we have a total population of 1600 plants, dividing them into 16 equal parts gives 100 plants per share. Thus, the dominant-dominant phenotype (Tall-Round) gets 9 shares (900 plants) and the double-recessive phenotype (Short-Wrinkled) gets 1 share (100 plants). This independent distribution proves that the genes for plant height and seed shape are located on separate chromosomes (or behave as if they are), leading to independent assortment.