BIOLOGY
NUCLEIC ACIDS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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10
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20
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40
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80
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Detailed explanation-1: -If 20 bases are thymine, then 20 bases must be adenine. So that makes 40 bases between adenine and thymine. 100 minus 40 is 60. So there must be 60 bases between guanine and cytosine.
Detailed explanation-2: -In a DNA sample, the percentage of adenine is 40% and percentage of thymine is 60%. What is your inference? According to Chargaff’s rule, Concentration of adenine=concentration of thymine. therefore if [A]=40% then the [T] will also be 40%.
Detailed explanation-3: -In the DNA structure, adenine base always pairs with thymine and cytosine always pairs with guanine. If 10% of the bases in a DNA are adenine, 10% of this DNA molecule must be thymine. The remaining 80% will be made up of 40% cytosine and 40% guanine since the bases pair with each other leaving a ratio of 1:4.
Detailed explanation-4: -Answer: There would be 20% Cytosine.
Detailed explanation-5: -Therefore, Guanine would be 20% and total of G+C = 40% and hence A+T would be 60% that is 30% each. Hence, option C is correct answer.