Question

explain the various types of dna, such as dna A, dna B, dna Z etc.

Answer 1

B-DNA is a type of DNA in which the double helix is right-handed with about 10–10.5 nucleotides per turn and have repeating unit 1 bp and rotation per base pair is 35.9º. This is a most common double helical structure.
A-DNA is a type of DNA in which the double helix is right-handed with about 11 nucleotides per turn and have repeating unit 1 bp and rotation per base pair is 32.7º.
Z-DNA is a type of DNA in which the double helix is left-handed with about 12 nucleotides per turn and have repeating unit 2 bp and rotation per base pair is 60º/2.