With reference to the contrasting traits studied by Mendel in pea, which one of the following statements is true?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Yellow seed colour is dominant over green seed colour.
Mendel studied seven pairs of contrasting traits in the garden pea: stem height (tall/dwarf), flower colour (violet/white), flower position (axial/terminal), pod shape (inflated/constricted), pod colour (green/yellow), seed shape (round/wrinkled) and seed colour (yellow/green). In each pair the first trait is the dominant one. It is the trait seen in the F1 generation.
(1) Yellow pod colour is dominant over green pod colour. — Incorrect. For pod colour, green is dominant and yellow is recessive.
(2) Green seed colour is dominant over yellow seed colour. — Incorrect. It is the other way round. Seed colour is the one pair in which yellow is dominant.
(3) Yellow seed colour is dominant over green seed colour. — Correct. A cross of a yellow-seeded plant with a green-seeded plant gives only yellow seeds in the F1 generation.
(4) Terminal position of flower is dominant over axial position of flower. — Incorrect. The axial flower position is dominant, and the terminal position is recessive.