1. Suppose one of the strands in your paper DNA model has the following sequence of bases:?

Question

A-T-G-C-A-A-T-T-C-C, what is the sequence of bases in the complementary strand? Write it out:

Answer 1

Remember:

1. The two strands of the DNA molecule are anti-parallel (one is 5' to 3', the other is 3' to 5')

2. By convention you always write DNA sequences 5' to 3' (except in virology).

so if your sequence is 5'-ATGCAATTCC-3' the complementary strand will be 3'-TACGTTAAGG-5'

now write it properly in the 5' to 3' orientation:

5'-GGAATTGCAT-3'

Answer 2

T - A - C - G - T - T - A- A- G - G

Remember base pairing rule:

Thymine (T) always matches with Adenine (A) and Cytosine (C) always matches with Guanine (G) in DNA.

Hope this helps!