In a typical plant cell, where does the light-dependent portion of photosynthesis primarily take place?

• A. Mitochondrial inner membrane
• B. Thylakoid membranes within chloroplasts
• C. Nucleus (within chromatin)
• D. Cytosol of the cell

Answer: (B)

Verified step by step guidance

1. Understand that photosynthesis occurs in chloroplasts, which are specialized organelles in plant cells responsible for converting light energy into chemical energy.
2. Recognize that photosynthesis has two main stages: the light-dependent reactions and the light-independent reactions (Calvin cycle).
3. Recall that the light-dependent reactions require light and take place in the thylakoid membranes, which are internal membrane structures within the chloroplasts.
4. Note that the thylakoid membranes contain pigments like chlorophyll that capture light energy and use it to produce ATP and NADPH.
5. Conclude that the light-dependent portion of photosynthesis primarily occurs in the thylakoid membranes within chloroplasts, not in the mitochondrial inner membrane, nucleus, or cytosol.