In a cross involving tall and dwarf pea traits, what ratio of tall to dwarf plants appears in the second generation?
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Answer and explanation
Correct answer: 3 : 1
In the usual monohybrid experiment, F1 plants are heterozygous Tt. Self-pollination gives Tt × Tt, producing TT, Tt, Tt and tt in a 1:2:1 genotypic ratio. Since TT and Tt are tall and only tt is dwarf, the observable phenotypic ratio is three tall plants to one dwarf plant, or 3:1. Therefore option A is correct.
Frequently asked questions
What is the correct answer to this question?
3 : 1
Why is this the correct answer?
In the usual monohybrid experiment, F1 plants are heterozygous Tt. Self-pollination gives Tt × Tt, producing TT, Tt, Tt and tt in a 1:2:1 genotypic ratio. Since TT and Tt are tall and only tt is dwarf, the observable phenotypic ratio is three tall plants to one dwarf plant, or 3:1. Therefore option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: World of Living. Topic: Heredity and Evolution.
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