Chapter 23, Problem 23.55SP

(a)

Interpretation Introduction

To determine: If Chargaff’s rule implied that equal amounts of guanine and adenine are present in DNA.

Interpretation: Whether Chargaff’s rule implied that the equal amounts of guanine and adenine are present in DNA is to be stated.

Concept introduction: James and Watson in $1953$ found that DNA contains the two complementary polynucleotide chains that are held together by the hydrogen bonds between the paired bases.

According to Chargaff’s rule the DNA contains the equimolar amounts of guanine and cytosine and also equimolar amounts of adenine and thymine.

This means that $\text{G}=\text{C}$ and $\text{A}=\text{T}$.

The pyrimidine bases are cytosine and thymine and purine bases are guanine and adenine that are present in DNA.

(b)

Interpretation Introduction

To determine: If Chargaff’s rule implied that the sum of purine residues equals the sum of pyrimidine residues.

Interpretation: Whether Chargaff’s rule implied that the sum of purine residues equals the sum of pyrimidine residues is to be stated.

Concept introduction: James and Watson in $1953$ found that DNA contains the two complementary polynucleotide chains that are held together by the hydrogen bonds between the paired bases.

According to Chargaff’s rule the DNA contains the equimolar amounts of guanine and cytosine and also equimolar amounts of adenine and thymine.

This means that $\text{G}=\text{C}$ and $\text{A}=\text{T}$.

The pyrimidine bases are cytosine and thymine and purine bases are guanine and adenine that are present in DNA.

(c)

Interpretation Introduction

To determine: If Chargaff’s rule applied only to double-stranded DNA or it would also apply to individual strand if the double helical strand were separated into its two complementary strands.

Interpretation: Whether Chargaff’s rule applied only to double-stranded DNA or it would also apply to individual strand if the double helical strand were separated into its two complementary strands is to be stated.

Concept introduction: James and Watson in $1953$ found that DNA contains the two complementary polynucleotide chains that are held together by the hydrogen bonds between the paired bases.

According to Chargaff’s rule, the DNA contains the equimolar amounts of guanine and cytosine and also equimolar amounts of adenine and thymine.

This means that $\text{G}=\text{C}$ and $\text{A}=\text{T}$.

The pyrimidine bases are cytosine and thymine and purine bases are guanine and adenine that are present in DNA.