When aaBbcc is crossed with AaBBCc then the ratio of hybrid for all the three genes is :-

Options

A. `1/8`
B. `1/4`
C. `1/16`
D. `1/32`

Answer

To solve the problem of finding the ratio of hybrids for all three genes when crossing the genotypes aaBbcc and AaBBCc, we will follow these steps:

### Step 1: Identify the Genotypes
We have two parent genotypes:
- Parent 1: aaBbcc
- Parent 2: AaBBCc

### Step 2: Analyze Each Gene Separately
We will analyze each gene (A, B, and C) separately to determine the probability of obtaining a heterozygous (hybrid) offspring for each gene.

#### Gene A:
- Parent 1: aa (homozygous recessive)
- Parent 2: Aa (heterozygous)

When we cross these:
- Possible offspring: Aa, aa
- The ratio of heterozygous (Aa) to total offspring is 1 Aa (hybrid) out of 2 total = 1/2.

#### Gene B:
- Parent 1: Bb (heterozygous)
- Parent 2: BB (homozygous dominant)

When we cross these:
- Possible offspring: BB, Bb
- The ratio of heterozygous (Bb) to total offspring is 1 Bb (hybrid) out of 2 total = 1/2.

#### Gene C:
- Parent 1: cc (homozygous recessive)
- Parent 2: Cc (heterozygous)

When we cross these:
- Possible offspring: Cc, cc
- The ratio of heterozygous (Cc) to total offspring is 1 Cc (hybrid) out of 2 total = 1/2.

### Step 3: Combine the Ratios
Now, we need to find the combined ratio of being heterozygous for all three genes (A, B, and C). Since these traits assort independently, we multiply the probabilities:

\[ \text{Ratio of hybrids} = \left(\frac{1}{2}\right) \times \left(\frac{1}{2}\right) \times \left(\frac{1}{2}\right) = \frac{1}{8} \]

### Conclusion
Thus, the ratio of hybrid offspring for all three genes is **1/8**.

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