How are polynucleotide DNA strands held together? (3 marks)

The two antiparallel strands of DNA are held together by hydrogen bonds joining the bases of each complementary nucleotide; Adenine is held to Thymine by 2 hydrogen bonds, and Guanine to Cytosine by 3 hydrogen bonds.

SA

Related Biology A Level answers

All answers ▸

Explain how gametes are produced by the process of meiosis.


What are different animal's cognitive limitations? How can we observe this in the wild?


What does ELISA measure?


What is the sliding filament theory?