Which one of the following is the complementary sequence of 5′ TTAAGCGTAC 3′?
A. 5’ GTACGCTTAA 3′
B. 5’ AATTCGCATG 3‘
C. 5‘ CATGCGAATT 3’
D. 5’ TTAAGCGTAC 3’
Correct answer : A. 5’ GTACGCTTAA 3′
How to calculate the complementary sequence of DNA:
Adenine binds with Thymine
Guanine binds with Cytosine
In the sequence given, make the following changes
Replace A with T
Replace T with A
Replace C with G
Replace G with C
Replace 5′ with 3′
Replace 3′ with 5′
That gives you the complementary sequence of DNA!
Note: Using the above method, we get the complementary DNA sequence as 3′ AATTCGCATG 5′. This is the same as 5′ GTACGCTTAA 3′ – which corresponds to option A.