Mendel’s experiment on pea plant: -

Character selected—Height of plant:

                        1] Dominant: - tall (T)

                        2] Recessive: - dwarf (t)

Parents: -          pure tall      x      dwarf

Genotype: -               TT             x                  tt

 Gametes: -                T                   x               t

  F1 generation: -                 Tt   (hybrid tall)

Result: - all the plants produced in f1 generation were tall in appearance.

DEFINITIONS AND TERMINOLOGIES

Define the following terms: - [1mark each]

1] Dominant: - the character from parents which is expressed in f1
generation is called as dominant characters. E.g. Tallness, red coloured flower,
etc.

2] Recessive: - The character from parents which is not expressed in f1 Generation is called as recessive character E.g. dwarfness, white flowers.etc.

3] Genotype: - the genetic constitution of any living organism is called as Genotype. E.g tt is the genotype for pure tall plant whereas tt is the genotype of dwarf plant.

4] Phenotype: - the external appearance of living organism is called as its phenotype. E.g. tallness of plant, colour of flower, etc.

5] Homozygous: - The organisms having identical gene for a particular character or trait trait is called a homozygous. E.g. TT [pure tall], tt [dwarf]

6] Heterozygous: - The organisms having two dissimilar genes for identical trait or character is called a heterozygous. E.g. Tt-heterozygous tall.

7] F1 generation: - The offspring produced from a cross between two parents is called as f1 generation.

8] Allele: - A pair of genes for alternate forms of characters called as alleles or allelomorph. They are present on the same locus.

9] Phenotypic ratio: - The ratio of individuals on the basis of external appearance in F2 generation is called phenotypic ratio.

10] Genotypic ratio: - The ratio of individuals obtained on the basis of actual genotypes is called as genotypic ratio.

11] Monohybrid cross: - The cross made between two homozygous plants for a single pair of contrasting character is called as monohybrid cross.

12] Monohybrid ratio: - The phenotypic and genotypic ratio obtained in monohybrid cross are called as monohybrid ratio.

13] Dihybrid cross: - The cross made between two homozygous plants for two pairs of contrasting characters is called as dihybrid cross.

14] Dihybrid ratio: - The phenotypic and genotypic ratio obtained in dihybrid cross are called as dihybrid ratio.

15] Offsprings: - The individuals produced after every cross are called as offsprings.

16] Progeny: - The offspring obtained through the successive generations by crossing parents is called as progeny.