Question

Choose the correct pair from the following: 

 

• A. I, III
• B. II, IV
• C. I, II
• D. III, IV

Hint:

In dihybrid crosses, remember the genotypic ratio of 9:3:3:1 for offspring, where each number represents different combinations of dominant and recessive alleles.

Answer 1

The Correct Option is A

To solve the problem, we need to identify the correct pair of genetic combinations based on Mendelian inheritance patterns.

1. Analyzing the Genetic Crosses:
We are given four genetic combinations with their corresponding probabilities:

• I. RrYy with a probability of 4/16
• II. Rryy with a probability of 1/16
• III. RrYY with a probability of 2/16
• IV. rrYy with a probability of 1/16

2. Understanding the Inheritance:
In this case, we are dealing with a dihybrid cross involving two traits. The allele combinations for each trait will follow the standard Mendelian inheritance ratios. The correct pairings of genetic combinations are:

• I. RrYy (4/16): This represents a heterozygous condition for both traits.
• III. RrYY (2/16): This represents a heterozygous condition for the first trait and homozygous dominant for the second trait.

3. Identifying the Correct Pair:
The correct genetic pair that matches the given probabilities is:
I = RrYy (4/16)
III = RrYY (2/16)

Final Answer:
The correct option is (A) I, III.