Benedict's solution is added to maple syrup and heated. the color changes from blue to orange. based on this result, what biological molecules are present in the maple syrup?

The Benedict's solution or the Fehling's solution is a chemical solution with clear blue color, which is a combination of the sodium citrate, sodium carbonate, and cupric sulphate pentahydrate. The Benedict's solution is used to test for the presence of the reducing sugars, such as glucose. When it is added into a solution and warmed, and it changes the color to orange, it confirms the presence of the reducing sugar in the testing solution.

Hence, the maple syrup contains reducing sugar.

and after water is usually warmed by the sun the water temperature raises and then evaporates .

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.