In pea plants, tall stem is dominant over dwarf stem. If two hybrid tall plants are crossed, what is the expected proportion of dwarf offspring?
Answer and explanation
Correct answer: One-fourth
Let T represent the dominant tall allele and t the recessive dwarf allele. A hybrid tall plant has genotype Tt, so the cross is Tt × Tt. The possible offspring are TT, Tt, Tt and tt. Only tt is dwarf, giving 1 out of 4 offspring, or 25%. Thus A is correct. The 3:1 ratio refers to tall:dwarf phenotypes, not to the dwarf proportion alone.
Frequently asked questions
What is the correct answer to this question?
One-fourth
Why is this the correct answer?
Let T represent the dominant tall allele and t the recessive dwarf allele. A hybrid tall plant has genotype Tt, so the cross is Tt × Tt. The possible offspring are TT, Tt, Tt and tt. Only tt is dwarf, giving 1 out of 4 offspring, or 25%. Thus A is correct. The 3:1 ratio refers to tall:dwarf phenotypes, not to the dwarf proportion alone.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: World of Living. Topic: Heredity and Evolution.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
