Question

5'- CCTTAAGGCTAATAGCAGGT-3'

a) What is the sequence of the complementary DNA strand (indicate 5' and 3' ends)?

b) underline the pyrimidines in the given sequence

c) what other components are also part of a DNA double strand molecules but are NOT indicated in this strand?

Answer 1

Ans

a) A double strand DNA is made up of two strands that have complimentary base pairing . So the sequence of the other strand will be :

3' - GGAATTCCGATTATCGTCCA - 5'

b) The pyrimidines present in DNA are thymine and cytosine .

These are underlined in the DNA strand as :

5' - CCTTAAGGCTAATAGCAGGT - 3'

c) DNA double strand has sugar , phosphate and nitrogenous base as the main components.

Here nitrogenous bases ( purines and pyrimidines) are shown , as well as the 5' and 3' ends of sugar are shown. The only component which is not indicated in this strand is the phosphate group.