In which organelle does photosynthesis occur?

Photosynthesis occurs in chloroplasts, which are specialized organelles found in the cells of plants and some algae. These organelles contain chlorophyll, the pigment responsible for capturing light energy from the sun. In the chloroplasts, light energy is converted into chemical energy through a series of reactions, primarily during the light-dependent and light-independent phases of photosynthesis. This process produces glucose and oxygen, which are essential for the survival of plants and provide energy for other organisms in the ecosystem.

The mitochondria are involved in cellular respiration, where they break down glucose to generate ATP, but they do not carry out photosynthesis. The nucleus contains the cell's genetic material and coordinates activities such as growth and reproduction, but it is not where photosynthesis takes place. The cell membrane acts as a barrier, regulating the movement of substances in and out of the cell, but it also does not play a direct role in photosynthesis. Thus, the chloroplasts are the correct answer as they are the site of photosynthesis in plant cells.