Question

The percentage of sequence identity for the following aligned sequence is:
V K S F L W T Q A L
V P S F R W T Q S L

• A. 10%
• B. 80%
• C. 30%
• D. 70%

Hint:

Identity = (Number of matches Total positions) $\times$ 100.

Answer 1

The Correct Option is D

Step 1: Concept
Sequence identity is the percentage of exact matches between two aligned sequences.

Step 2: Meaning
To calculate, count the number of identical residues and divide by the total length of the alignment.

Step 3: Analysis
Comparing the sequences:
1. V=V (Match)
2. K/P (Mismatch)
3. S=S (Match)
4. F=F (Match)
5. L/R (Mismatch)
6. W=W (Match)
7. T=T (Match)
8. Q=Q (Match)
9. A/S (Mismatch)
10. L=L (Match)
Total matches = 7. Total length = 10. Identity = (7/10) * 100 = 70%.

Step 4: Conclusion
The identity percentage is 70% based on the 7 matching positions. Final Answer: (D)