Question

In the context of chemical evolution, DNA's structure is interesting because it suggests a possible copying mechanism. What about DNA's structure facilitates copying?

a.The nitrogenous bases are located on the inside of the double helix.
b.The strands of the double helix are complementary.
c.DNA always goes from 5 to 3.
d. It has the same number of purines and pyrimidines

Answer 1

DNA's double helix structure, b) with complementary and anti-parallel strands, enables it to accurately replicate by using each strand as a template for creating a new complementary strand.

Step-by-step explanation:

The structure of DNA facilitates copying because of a few key features. Firstly, the double helix structure has the nitrogenous bases located inside, paired in a specific manner: adenine (A) with thymine (T), and cytosine (C) with guanine (G). These pairs are connected through hydrogen bonds. The pairing of bases is crucial for replication because each base can only pair with its complement (A with T, C with G), assuring accurate copying when DNA replicates. Furthermore, the strands of DNA are complementary and run in opposite directions (anti-parallel). This means that the 5' end of one strand faces the 3' end of the complementary strand, which is significant during the replication process. Lastly, the covalent bonds between the phosphate group of one nucleotide and the sugar of the next create a strong backbone on the outside of the helix which holds the whole structure together while the strands are being copied.