Question

in which two ways does base pairing allow dna to be copied with very few errors?

a. dna polymerase detects when the wrong base has been added and fixes the error.
b. base pairing rules ensure that new strands are complementary to the template strands.
c. the base sequence of the growing strand can be slightly different from the sequence of the template strand.
d. hydrogen bonds between bases hold the strands securely together during replication.

Explanation:

• Option A: DNA polymerase has proof - reading ability. It can detect and correct incorrect base pairings during DNA replication, which helps in minimizing errors.
• Option B: Base - pairing rules (A - T and G - C) ensure that the new strand synthesized is complementary to the template strand. This complementary base - pairing is a fundamental mechanism for accurate DNA replication.
• Option C: If the base sequence of the growing strand is different from the template strand (other than the complementary nature), it would lead to errors, not help in minimizing them.
• Option D: While hydrogen bonds between bases hold the strands together, this property alone does not directly explain how base - pairing allows for error - free copying. The key is the specific complementary base - pairing rules and the proof - reading ability of DNA polymerase.

Answer:

A. DNA polymerase detects when the wrong base has been added and fixes the error.
B. Base pairing rules ensure that new strands are complementary to the template strands.