Question

Watson and Crick derived their model of DNA structure not from their own laboratory research but rather through the analysis and interpretation of experimental data generated by others, such as Erwin Chargaff, Rosalind Franklin, and Maurice Wilkins. Which of the following provides evidence that DNA nucleotides are arranged as complementary base pairs?
A. DNA nucleotides contain a five-carbon deoxyribose sugar, a phosphate group, and one of four possible nitrogenous bases.
B. The nucleotides forming a single strand of DNA are linked together by covalent phosphodiester bonds.
C. Percentages of adenine and thymine are approximately equal to one another, and the percentages of cytosine and guanine are approximately equal to one another.
D. Complementary strands of DNA are antiparallel.

Answer 1

Answer: C

Explanation: The evidence that percentages of adenine and thymine are approximately equal and likewise that of cytosine and guanine. This is based on Erwin Charging's base composition studies. The DNA nucleotide are arranged as base with adenine on one strand forming double bonds with thymine on the complimentary strand likewise cytosine on one strand forms triple bond with guanine on the complementary

Answer 2

Answer:

C. Percentages of adenine and thymine are approximately equal to one another, and the percentages of cytosine and guanine are approximately equal to one another.

Explanation:

A nucleotide is made up of a sugar (deoxyribose), a phosphate group, and one of four nitrogenous

(Purine and Pyrimidine) bases: adenine (A), thymine (T), guanine (G) or cytosine (C).

Each nucleotide base can hydrogen-bond with a specific partner base in a process known as complementary base pairing.

Cytosine forms three hydrogen bonds with guanine while adenine forms two hydrogen bonds with thymine. These hydrogen-bonded nitrogenous bases are often referred to as base pairs.