Answer:
Sample A
T= 21.3% and A= 21.3%
G=28.7% and C= 28.7%
SAMPLE B
T=28.7% and A= 28.7%
G= 21.3% and C= 21.3%
Sample A would have higher melting temperature
Explanation:
According to given information, sample A contains 21.3% thymine.
Percentage of adenine in sample A= 21.3% (Since adenine base pairs with thymine, so, adenine and thymine are present in equal amount in a double stranded DNA)
Total of A+T in sample A= 21.3 + 21.3 = 42.6%
G+ C content of sample A= 100-42.6= 57.4%
Percent G content of sample A = 57.4/2 = 28.7%
Percent C content of sample A = 28.7%
SAMPLE B:
According to the given information, sample B contains 28.7% thymine.
Therefore, percent of Adenine base in sample B= 28.7%
Total of A+T content in sample B= 28.7 + 28.7 = 57.4%
G + C content of the sample B = 100-57.4= 42.6%
Percent G content of the sample B= 42.6/2= 21.3%
Percent C content of sample B = 21.3%
There are three hydrogen bonds between a GC pair while there are only two hydrogen bonds between AT pair. The DNA content with higher GC content has higher melting temperature. Therefore, sample A would have higher melting temperature.