Question

How many different type of gametes can potentially be produced by an organism with the genotype aaBbccdd?

• A. 2
• B. 4
• C. 8
• D. 16

Hint:

To quickly solve these problems, just scan the genotype and count how many pairs have one capital and one lowercase letter (like Bb). Ignore any pairs with two capital (BB) or two lowercase (bb) letters. Then, calculate 2 to the power of that count.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The number of different types of gametes an organism can produce is determined by the number of heterozygous gene pairs in its genotype. Homozygous gene pairs (e.g., aa, cc, dd) produce only one type of allele in the gametes, so they do not contribute to the variety of gametes.

Step 2: Key Formula or Approach:
The formula to calculate the number of different gametes is:
\[ \text{Number of gamete types} = 2^n \] where \( n \) is the number of heterozygous gene pairs.

Step 3: Detailed Explanation:
1. Identify the genotype: The given genotype is aaBbccdd.
2. Count the heterozygous pairs (n): We examine each gene pair:
- aa: Homozygous
- Bb: Heterozygous
- cc: Homozygous
- dd: Homozygous
There is only one heterozygous pair (Bb). Therefore, \( n = 1 \).
3. Calculate the number of gametes:
Using the formula \( 2^n \), with \( n = 1 \):
\[ \text{Number of gametes} = 2^1 = 2 \] The two possible types of gametes are aBcd and abcd.

Step 4: Final Answer:
The organism can produce 2 different types of gametes. Thus, option (A) is correct.