The cells of a plant help the plant maintain its life functions. What part of a plant cell has the function of producing sugar in the presence of sunlight?

CHLOROPLAST

Explanation:

As stated in this question, plant cells are capable of producing their own food in form of sugar (glucose) using energy from sunlight in a process called PHOTOSYNTHESIS. Photosynthesis is the process by which green plants and other certain organisms synthesize their own food using light energy.

The ability to carry out this photosynthetic function is embedded in a structure found in plant cells called CHLOROPLAST. Chloroplast contains a pigment called CHLOROPHYLL, which captures light energy from the sun. Generally, the the function of producing sugar in the presence of sunlight (photosynthesis) occurs in the CHLOROPLAST.