Question

In an experiment to study independent inheritance of two separate traits: shape and colour of seeds, the ratio of the different combinations in F₂ progeny would be

• A. 1 : 3
• B. 1 : 2 : 1
• C. 9 : 3 : 3 : 1
• D. 9 : 1 : 1 : 3

Answer 1

The Correct Option is C

Step 1: Experiment Overview:
This experiment investigates the independent inheritance of seed shape and color. Mendel's laws state that traits controlled by different gene pairs on separate chromosomes will assort independently in F₂ offspring.

Step 2: Mendel's Law of Independent Assortment Explained:
This law posits that genes for distinct traits segregate independently during gamete formation. Crossing two heterozygous pea plants (e.g., TtYy for seed shape and color, where T=tall, t=dwarf, Y=yellow, y=green) results in an F₂ generation with a 9:3:3:1 phenotypic ratio.
- The '9' represents offspring with two dominant traits (e.g., round, yellow seeds).
- The '3's represent offspring with one dominant and one recessive trait (e.g., round, green seeds or wrinkled, yellow seeds; and wrinkled, green seeds).
- The '1' represents offspring with two recessive traits (e.g., wrinkled, green seeds).

Step 3: Conclusion:
In accordance with Mendel's law of independent assortment, the F₂ progeny will display seed shape and color combinations in a ratio of 9:3:3:1.