Question

(a) If we cross pure-bred tall (dominant) pea plants with pure-bred dwarf (recessive) pea plants we get pea plants of F1 generation. If we now self-cross the pea plants of F1 generation, then we obtain pea plants of F2 generation.
(i) What do the plants of F1 generation look like?
(ii) What is the ratio of tall plants to dwarf plants in F2 generation?
(iii) State the type of plants not found in F1 generation but appeared in F2 generation, mentioning the reason for the same.
(b) What are homologous structures? Give an example. Is it necessary that homologous structures always have common ancestors?

Answer 1

Answer:

Explanation:

A 3 Short plants are not found in f1 generation because it contained all hybrid tall plants

Answer 2

Dwarfism and homologous structures

Explanation:

(a)  Dwarfism

1. All plants of F2 generation are tall.
2. The ratio of tall to dwarf plants in F2 is 3:1.
3. The dwarfs are not found in F1, but occur in F2 as the trait is recessive. Please refer the attached diagram for an explanation.

(b) Homologous structures are organs or skeletal elements of animals and organisms that, by virtue of their similarity, suggest their connection to a common ancestor. These structures do not have to look exactly the same, or have the same function.