Question

If we pure-bred tall (dominant) pea plant with pure-bred dwarf (recessive) pea plant we will get pea plants of F₁ generation. If we now self-cross the pea plant of F₁ generation, then we obtain pea plants of F₂ generation.

(a) What do the plants of F₂ generation look like?

(b) State the ratio of tall plants to dwarf plants in F₂ generation.

(c) State the type of plants not found in F₁ generation but appeared in F₂ generation, mentioning the reason for the same.

Answer 1

When a pure breeding tall pea plant is crossed with a pure breeding dwarf pea plant

(a) All the plants in the F₁ generation appear tall.

(b) The ratio of tall pea plant to dwarf pea plants is 3 (tall) : 1 (dwarf).

(c) The dwarf plant does not appear in the F₁ generation but appears in the F₂ generation because the progeny produced in the F₁generation were heterozygous (Tt). Hence, when they were selfed for obtaining the F₂ generation, dwarf plants were also formed in the progeny. The cross involved in as follows