Solution

This sample has more hydrogen bonding acting between its strands than the sample below. It has more guanine and cytosine base pairs hence more hydrogen bonding holding the strands together.

The sample on the right has more adenine-thymine base pairs hence the amount of hydrogen bonding that can take place between the two strands is not as great as the sample above.

A greater temperature is therefore needed to separate the strands of the sample above.