Biology
A homozygous tall plant (T) bearing red coloured (R) flowers is crossed with a homozygous dwarf (t) plant bearing white (r) flowers :
(i) Give the genotype and phenotype of the plants of F1 generation.
(ii) Mention the possible combinations of the gametes that can be obtained from the F1 hybrid plant.
(iii) State the Mendel's law of Independent Assortment.
(iv) Mention the phenotypes of the offspring's obtained in F2 generation.
(v) What is the phenotypic ratio obtained in F2 generation?
Answer
(i) Genotype of F1 generation — Heterozygous Tall with Red flowers (TtRr)
Phenotype — All heterozygous tall and red.
(ii) Below are the possible combinations of the gametes that can be obtained:
- TR — Tall and Red
- tR — Dwarf and Red
- Tr — Tall and White
- tr — Dwarf and White
(iii) Mendel's law of Independent Assortment states that when there are two pairs of characters, the distribution of the alleles of one character into the gametes is independent of the distribution of the alleles of the other character (as seen in the production of gametes of the F1 hybrid in dihybrid cross).
(iv) Tall red, Dwarf red, tall white, dwarf white.
(v) 9:3:3:1
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