HEREDITY
MUTATIONS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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cytosine
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guanine
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thymine
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uracil
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Detailed explanation-1: -DNA has equal number of adenine and thymine residues (A=T) and equal number of guanine and cytosine (G=C).
Detailed explanation-2: -Correct answer: There are four bases in DNA: adenine, thymine, guanine, and cytosine. Adenine always pairs with thymine, so the number of adenine residues always equals the number of thymine residues. Guanine always pairs with cytosine, which means they are always present in equal amounts as well.
Detailed explanation-3: -That being said, we know that the amount of adenine (A) is equal to the amount of thymine (T), and the amount of guanine (G) is equal to the amount of cytosine (C) due to the complementarity of DNA; A=T and C=G.
Detailed explanation-4: -There are four nitrogenous bases in DNA, two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). A DNA molecule is composed of two strands.
Detailed explanation-5: -It is given that the total amount of thymine and adenine is = 45%, then the total amount of Guanine and cytosine will be equal to 100%-45% = 55%. Also, % G = % C, Therefore-%G =% C = 55 %/2 = 27.5 %. So, the percentage of Guanine in DNA will be equal to 27.5 %.