In a typical leaf cell, where does photosynthesis primarily take place?

• A. In the central vacuole, where water is stored for photosynthesis
• B. In the mitochondria, primarily on the inner mitochondrial membrane
• C. In the nucleus, where DNA directs the synthesis of photosynthetic enzymes
• D. In the chloroplasts, especially within the thylakoid membranes and stroma

Answer: (D)

Verified step by step guidance

1. Identify the organelle responsible for photosynthesis in plant cells, which is the chloroplast.
2. Understand that within the chloroplast, photosynthesis occurs mainly in two regions: the thylakoid membranes and the stroma.
3. Recognize that the thylakoid membranes contain pigments like chlorophyll that capture light energy for the light-dependent reactions.
4. Know that the stroma is the fluid-filled space surrounding the thylakoids where the Calvin cycle (light-independent reactions) takes place, synthesizing sugars.
5. Eliminate other options by recalling that the central vacuole stores water but does not perform photosynthesis, mitochondria are involved in cellular respiration, and the nucleus directs protein synthesis but is not the site of photosynthesis.