AP BIOLOGY

THE MOLECULAR BASIS OF INHERITANCE

DNA REPLICATION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
If a fruit fly has 40% Guanine in it’s DNA, how much Adenine does it have?
A
10%
B
20%
C
30%
D
40%
Explanation: 

Detailed explanation-1: -It guanine is 40% then cytosine will also be 40%. Similarly, Aenine pairs with thymihne, if guanine is 40%, the remaining 60% will be Adenine. So Theymine will also be 60%.

Detailed explanation-2: -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.

Detailed explanation-3: -According to Chargaff’s rule, Concentration of adenine=concentration of thymine. therefore if [A]=40% then the [T] will also be 40%.

Detailed explanation-4: -The percentage of guanine is 20%.

There is 1 question to complete.