Question

It is important that the two strands of DNA near the front end of a gene are able to separate easily so that the gene can be expressed at the appropriate time. What should base composition in this part of the gene therefore be and why?

a. it should be AT-rich since the larger number of H bonds in that region of the gene will allow the strands to separate more easily
b. it should be AT-rich since the smaller number of H bonds in that region of the gene will allow the strands to separate more easily
c. it should be GC-rich since the smaller number of H bonds in that region of the gene will allow the strands to separate more easily
d. it should be AT-rich since the smaller number of H bonds in that region of the gene will allow the strands to separate less easily.

Answer 1

The base composition of a gene where strands separate should be AT-rich due to the fewer hydrogen bonds between A and T, easing strand separation for gene expression.

Step-by-step explanation:

The base composition in the part of the gene where the two strands separate should be AT-rich. This is because adenine (A) pairs with thymine (T) using two hydrogen bonds, which are fewer and therefore weaker compared to the three hydrogen bonds between guanine (G) and cytosine (C). This lesser number of hydrogen bonds in AT-rich regions allows the DNA strands to separate more easily, which is important for gene expression and the initiation of transcription processes such as the binding of TATA-binding protein (TBP) to the TATA box.