Erwin Chargaff's work on the composition of nucleic acids began in 1944. His findings, which later became known as Chargaff's rules, detail the specific pairings that occur in double-stranded DNA molecules.

Question

Erwin Chargaff's work on the composition of nucleic acids began in 1944. His findings, which later became known as Chargaff's rules, detail the specific pairings that occur in double-stranded DNA molecules.

According to one of Chargaff's rules, a section of DNA molecule that contains 50 base pairs and has 15 adenine bases must also contain —

A 15 guanine bases

® 15 cytosine bases

© 15 thymine bases

D 15 uracil bases

Answer 1

According to Chargaff's rules, the amount of adenine should be equal to the amount of thymine, and the amount of guanine should be equal to the amount of cytosine in a DNA molecule. Therefore, if there are 15 adenine bases in a section of DNA with 50 base pairs, there must also be 15 thymine bases. So the correct answer is C) 15 thymine bases. Uracil bases are not found in DNA, but are found in RNA.