Question

One side strand of a DNA molecule read 3' ATC GAC CAT 5'. What would the complementary strand read?




a
5' ATC GAC CAT 3'
b
5' TAG CTG GTA 3'
c
5' TAG CCG GTA 3'
d
5' ATC CCG GTA 3'

Answer 1

To find the complementary strand of the given DNA sequence, you need to pair the bases according to the base pairing rules: A (adenine) pairs with T (thymine), and C (cytosine) pairs with G (guanine).

The provided sequence is:
3' ATC GAC CAT 5'

Complementary base pairing gives:
- A pairs with T
- T pairs with A
- C pairs with G
- G pairs with C
- C pairs with G
- A pairs with T
- C pairs with G
- C pairs with G
- A pairs with T
- T pairs with A

Now, write the complementary sequence in the 5' to 3' direction (since the complementary strand runs antiparallel to the original strand):
5' TAG CTG GTA 3'

Thus, the correct answer is:
**b 5' TAG CTG GTA 3'**.