Question

The base sequence in one of the strands of DNA is TAGCATGAT.
(i) Give the base sequence of its complementary strand.
(ii) How are these base pairs held together in a DNA molecule?
(iii) Explain the base complementarity rules. Name the scientist who framed this rule.

Answer 1

Explanation:

1. ATCGTACTA
2. Through Hydrogen bonds

Answer 2

Complementary Rule of base pairs

Explanation:

• I) The base sequence for its reciprocal strand is 'ATCGTACTA'.  
• ii) These base pairs are held together by hydrogen bonds. Among A and T 2 hydrogen bonds are available and between G and C 3 hydrogen bonds are available.  
• iii) Base complementary Rules were proposed by Chargaff. It states that bond pairs are constantly formed between A(Adenine), T (Thymine) and between C (Cytosine), G (Guanine) for example a purine consistently matches pyrimidine and the other way around.