Written by Prerak Juthani (PEACE Advisor)
Assume that each of the sequences represents one strand from a double stranded genome of a random organism. Which organism, based on the genome below, would be able to survive in the hottest environment?
a) 5’ACGTACGTACGTACGTT3’
b) 5’GGGCCCTTTAAACGGG3’
c) 5’CCCCCCCCCCCCCUUCC3’
d) 5’ATATATATATATATAT3’
e) none of the above. UV light would demolish all.
Click “Read More” to see the answers.
a) 5’ACGTACGTACGTACGTT3’
b) 5’GGGCCCTTTAAACGGG3’
c) 5’CCCCCCCCCCCCCUUCC3’
d) 5’ATATATATATATATAT3’
e) none of the above. UV light would demolish all.
Click “Read More” to see the answers.
The correct answer is C.
The important part to remember here is that C pairs with G and that A pairs with T. From there, the next thing to remember is that CG base pairs tend to have three hydrogen bonds holding them together and AT base pairs have two hydrogen bonds holding them together. Based on this, a DNA molecule that is 100% GC will have a higher boiling point than a DNA molecule that is 100% AT simply because there are more hydrogen bonds between the base pairs in the first molecule. Accordingly, in this question, the DNA that has the most Cs or Gs will have the most CG base pairs and consequently, have the highest boiling point. A higher boiling point directly correlates with the ability to survive in a hotter environment.