In autumn, chlorophyll is degraded in the leaves of deciduous trees. why do the leaves change color to shades of yellow, orange, or red?

Due to the coloring pigment Anthocyanins.

Explanation:

It is the Anthocyanins which is the factor behind the yellow , orange and red color of leaves.

During autumn season, the leaves of a plant stop making food. As a result of this the chlorophyll with in the leaves of such plants start degrading. Since the chlorophyll gives green color to the leaves, thus once this green pigment is degraded leaves no more remain green. They first convert to yellow color , then orange and finally red due to the coloring pigment "Anthocyanins"

In some cases even the stems start changing color due to high level of Anthocyanins

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.