Describe the experiments that revealed the structure of the genetic material. If a sample of DNA contains 8% adenine (A), then what are the percentages of thymine (T), cytosine (C), and guanine (G)

One of the earlier experiments that confirmed DNA and not proteins as genetic material was conducted by Alfred Hershey and Martha Chase

Hershey and Chase experiment showed the genetic material of virus is DNA not protein. Their experiments demonstrated that Phage are composed of DNA and protein, when phage infect bacteria, their DNA enters the host bacterial cell but not protein before infection

Hershey and Chase experiment prove that DNA is the hereditary material.

From chargaff base pairing rule, the ratio of purine to pyrimidine is a cell is 1:1. Since adenine pair with thymine and cytosine pair with quanine, this means the percentage of adenine will equal the percentage of thymine.

%A = %T and %G = %C.

%A + %T + %G + %C = 100

If a DNA contains 8% adenine, therefore the percentage of thymine is 8%

8% + 8% + %G + %C = 100%

16% + %G + %C = 100%

%G + %C = 100%-16%

%G + %C = 84% = 84%/2 = 42%

Since %G = %C

Then %G = 42%, %C = 42

Answer: 8% Thymine

The DNA structure is complementary. The bases are in equal proportion on each side of the strands. Adenine always pair with thymine. while cytosine pairs with Guanine in the usual Purines-Pyrimidine paring fashion.

Adenine and Guanine are Purines. and Cytosine and Guanine are Pyrimidine.

Therefore if there are 8 % of Adenine bases on one DNA strand, the same bases percentage of pyrimidine 8% Thymine should be on the opposite strands of DNA chain for perfect complementary paring.