THE MOLECULAR BASIS OF INHERITANCE
THE SEARCH FOR INHERITABLE MATERIAL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The amount of adenine in a set of DNA is equal to the amount of guanine
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Each of the four bases are always found in equal quantities.
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The four bases found in DNA are adenine, thymine, cytosine and guanine.
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The concentrations of the four bases do not vary among species.
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Detailed explanation-1: -Using this method, Chargaff separated the different components found in DNA and discovered that adenine, guanine, thymine, and cytosine existed in fixed ratios and that each species possessed a different proportion of each base pair.
Detailed explanation-2: -Erwin Chargaff found that in DNA, the ratios of adenine (A) to thymine (T) and guanine (G) to cytosine (C) are equal. This parity is obvious in the final DNA structure.
Detailed explanation-3: -In 1947 Chargaff showed that the composition of DNA, in terms of the relative amounts of the A, C, G and T bases, varied from one species to another. This molecular diversity added evidence that DNA could be the genetic material.
Detailed explanation-4: -Chargaff promptly turned his laboratory to the study of DNA and its four chemical bases-adenine, cytosine, guanine and thymine-using a refinement of the chromatography technique of two British scientists, John Martin and Richard Synge.
Detailed explanation-5: -In 1950, he discovered that the amounts of adenine and thymine in DNA were roughly the same, as were the amounts of cytosine and guanine. This later became known as the first of Chargaff’s rules. Honors awarded to him include the Pasteur Medal (1949) and the National Medal of Science (1974).