THE MOLECULAR BASIS OF INHERITANCE
DNA REPLICATION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
A-T, G-C
|
|
|
A-G, C-T
|
|
|
T-G, A-C
|
|
|
A-A, T-T, G-G, C-C
|
Detailed explanation-1: -C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)
Detailed explanation-2: -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-3: -Final answer: Adenine-Thymine is the correct base pairing for DNA molecules.
Detailed explanation-4: -Bases pair up with each other in a consistent way, and this process is called complementary base pairing, or Watson-Crick base pairing. This consistent pairing of bases allows DNA to accurately replicate itself. It also allows DNA to be transcribed accurately into RNA and then translated from RNA to amino acids.
Detailed explanation-5: -Quantitatively, each GC base pair is held together by three hydrogen bonds, while AT and AU base pairs are held together by two hydrogen bonds. To emphasize this difference, the base pairings are often represented as “G≡C” versus “A=T” or “A=U".