If the sequence of one strand of DNA is written as: 5'- ATCGTGCTATGAGCATGC-3'.
The sequence of its complementary strands will be?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 3'- TAGCACGATACTCGTACG-5'
Explanation:
The given DNA strand is:
5'- ATCGTGCTATGAGCATGC -3'
To find the complementary strand:
- Base Pairing Rules:
- A (Adenine) pairs with T (Thymine)
- T (Thymine) pairs with A (Adenine)
- C (Cytosine) pairs with G (Guanine)
- G (Guanine) pairs with C (Cytosine)
- Complementary Sequence:
- Write the complementary bases in the opposite direction (3' → 5') to maintain antiparallel structure.
Given Strand (5'→3'):
TCGTGCTATGAGCATGC
Complementary Strand (3'→5'):
TAGCACGATACTCGTACG
Other Options:
- Option 1: Incorrect because it is written 5'→3' (should be 3'→5').
- Option 3 & 4: Incorrect because they contain Uracil (U), which is found in RNA, not DNA.