AP BIOLOGY

Detailed explanation-1: -Erwin Chargaff found that in DNA, the ratios of adenine (A) to thymine (T) and guanine (G) to cytosine (C) are equal.

Detailed explanation-2: -15251. Discovering the rules of complementary base pairing, Erwin Chargaff. Erwin Chargaff talks about his discovery – a major step for building the DNA model.

Detailed explanation-3: -Chargaff’s rules state that in the DNA of any species and any organism, the amount of guanine should be equal to the amount of cytosine and the amount of adenine should be equal to the amount of thymine. Further a 1:1 stoichiometric ratio of purine and pyrimidine bases (i.e., A+G=T+C ) should exist.

Detailed explanation-4: -As a biochemist at Columbia University in the 1940’s, Dr. Chargaff discovered regularities among the four chemical units of DNA known as bases, pointing directly to its role as the hereditary material of living organisms. But he was unable to interpret the meaning of his finding, a failure that allowed Dr.

Detailed explanation-5: -Key conclusions from Erwin Chargaff’s work are now known as Chargaff’s rules. The first and best known achievement was to show that in natural DNA the number of guanine units equals the number of cytosine units and the number of adenine units equals the number of thymine units.