A homozygous tall plant (T) bearing red coloured (R) flowers

Human Evolution (10)

A homozygous tall plant (T) bearing red coloured (R) flowers is crossed with a homozygous dwarf (t) plant bearing white (r) flowers:

1. Give the genotype and phenotype of the plants of F₁ generation.
2. Mention the possible combinations of the gametes that can be obtained from the F₁ hybrid plant.
3. State the Mendel’s law of Independent Assortment.
4. Mention the phenotypes of the offspring's obtained in F₂ generation.
5. What is the phenotypic ratio obtained in F₂ generation?

Answer

(i) Genotype of F₁ generation: Heterozygous Tall with Red flowers

TtRr

Phenotype: tall red flowers       

(ii) TR, tR, Tr, tr                                                  

(iii) Law of Independent assortment

When there are two pairs of contrasting characters, the distribution of the members of one pair into the gametes is independent of the distribution of the other pair.

(iv) Tall red , Dwarf red , tall white; dwarf white.

(v) 9:3:3:1