A pure breeding red flower variety of pea plant (RR) is crossed with a pure breeding white flower variety of pea plant (rr). Draw a Punnett square to find out the Phenotypic and Genotypic ratios of the progeny belonging to the F2 generation.
| R | r | |
|---|---|---|
| R | RR | Rr |
| r | Rr | rr |
Phenotypic Ratio: 3 : 1
RR and Rr will be red flowering plants, while rr will be a white flowering plant.
Genotypic Ratio: 1 : 2 : 1
RR (dominant homozygous), Rr (dominant heterozygous), rr (recessive homozygous)
More ICSE Moderate level questions
State Mendel's 'Law of Segregation'.
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Define the term Mutation.
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A farmer cultivates a unique species of tomato plants. The two traits selected for breeding were: Colour of the fruits and height of the plants. The farmer initially crosses a homozygous tall plant bearing red fruits (TTRR) with a dwarf plant bearing yellow fruits (ttrr) and the genotype of all the offsprings of the F1 generation was TtRr. Next, he crosses two F1 generation plants (TtRr). (a) Explain the phenotype of the offsprings of the F1 generation obtained from the initial cross. (b) Mention the phenotypic ratio of the F2 generation offsprings. (c) State Mendel's Law of Independent Assortment.
