To determine which two organisms are the most distantly related to each other, we need to calculate the Hamming distance between the DNA sequences of each pair of organisms. The Hamming distance is the number of positions at which the corresponding bases differ in two sequences of equal length.
Here are the base sequences for the organisms:
- W: C A C A A T C G A A
- X: G T C A A T G G T G
- Y: C T C A A T C G T A
- Z: C T C A T T C G T A
We will compare each pair and count the differences:
1. W and X:
- Compare: C-G, A-T, C-C, A-A, A-A, T-T, C-G, G-G, A-T, A-G
- Differences: 5 (positions 1, 2, 7, 9, 10)
2. W and Y:
- Compare: C-C, A-T, C-C, A-A, A-A, T-T, C-C, G-G, A-T, A-A
- Differences: 2 (positions 2, 9)
3. W and Z:
- Compare: C-C, A-T, C-C, A-A, A-T, T-T, C-C, G-G, A-T, A-A
- Differences: 3 (positions 2, 5, 9)
4. X and Y:
- Compare: G-C, T-T, C-C, A-A, A-A, T-T, G-C, G-G, T-T, G-A
- Differences: 3 (positions 1, 7, 10)
5. X and Z:
- Compare: G-C, T-T, C-C, A-A, A-T, T-T, G-C, G-G, T-T, G-A
- Differences: 4 (positions 1, 5, 7, 10)
6. Y and Z:
- Compare: C-C, T-T, C-C, A-A, A-T, T-T, C-C, G-G, T-T, A-A
- Differences: 1 (position 5)
We summarize the Hamming distances as follows:
- W and X: 5
- W and Y: 2
- W and Z: 3
- X and Y: 3
- X and Z: 4
- Y and Z: 1
The pair of organisms with the maximum Hamming distance are W and X, with a Hamming distance of 5.
Thus, the most distantly related organisms are:
- Answer: A (W and X)
