BIOMOLECULES AND ENZYMES

Detailed explanation-1: -As night length increases in the autumn, chlorophyll production slows down and then stops and eventually all the chlorophyll is destroyed. The carotenoids and anthocyanin that are present in the leaf are then unmasked and show their colors.

Detailed explanation-2: -In autumn when it starts to get cold, some plants stop making chlorophyll. Instead, those plants break down chlorophyll into smaller molecules. As chlorophyll goes away, other pigments start to show their colors. This is why leaves turn yellow or red in fall.

Detailed explanation-3: -Deciduous trees shed their leaves to survive. Once the winter has passed, the soil loses most of its moisture content. Since there is a derth off water, the tree must conserve all the water it needs to survive. It does so by shedding leaves which utilise water for photosynthesis.

Detailed explanation-4: -The change in light and temperature during winter causes deciduous trees to shut down their food making factories and the green colour-the chemical chlorophyll, disappears from the leaves. As the bright green fades away, we see yellow and orange colours.