There are called Amino Acids.
I would say A. Quantitative data involves numbers and stuff like that. Unlike qualitative data, which involves pictures and not numerical data. I hope this helped.
Think of it this way:
DNA inside cells store all the genetic information on a person's looks, eye colour, hair colour etc. It makes them unique. The analogy of being like books in a library basically suggests that in a library there is so much information and every book is different with different knowledge... That's basically what DNA is; millions of different information things.
If an A (Adenine) were swapped for a T (Thymine) it will lead to A TRANSVERSION TYPE OF POINT MUTATION.
Replacement of an A with a T is a transversion type of point mutation because in transversion the purine is replaced with a pyrimidine. Since in this case only one nucleotide is replaced, it is a point mutation.
