How many different kinds of gametes will be produced by a plant having the genotype AABbCC ?

Question

Accepted Answer

To determine the number of different kinds of gametes produced by a plant with the genotype AABbCC, we need to consider the genetic makeup and how gametes are formed.

1. **Explanation for Option 4 (Correct Answer):**
   - The genotype AABbCC consists of three gene loci: AA, Bb, and CC.
   - For each gene locus, the number of different alleles determines the number of different gametes that can be produced.
   - The AA locus is homozygous, meaning it has two identical alleles (A and A). Therefore, it can only contribute one type of allele (A) to the gametes.
   - The Bb locus is heterozygous, meaning it has two different alleles (B and b). This locus can contribute either B or b to the gametes.
   - The CC locus is homozygous, meaning it has two identical alleles (C and C). Therefore, it can only contribute one type of allele (C) to the gametes.
   - To find the total number of different gametes, we multiply the number of possibilities at each locus: 1 (from AA) × 2 (from Bb) × 1 (from CC) = 2.
   - Therefore, the plant will produce two different kinds of gametes: ABC and AbC.

2. **Explanation for why other options are incorrect:**
   - **Option 1 (Three):** This option is incorrect because the calculation of gamete types is based on the number of heterozygous loci. Since there is only one heterozygous locus (Bb), it results in 2 types of gametes, not 3.
   - **Option 2 (Four):** This option is incorrect because it assumes more variability than is present. With only one heterozygous locus, the maximum number of different gametes is 2, not 4.
   - **Option 3 (Nine):** This option is incorrect because it overestimates the number of gametes. Nine would be the result if all three loci were heterozygous (3 × 3 × 3), which is not the case here.

In conclusion, the correct answer is Option 4, as the plant with genotype AABbCC can produce only two different kinds of gametes due to the presence of one heterozygous locus.