A Level Biology Practice Exam

Which organelles are responsible for photosynthesis in plant cells?

1. Mitochondria

2. Chloroplasts

3. Ribosomes

4. Endoplasmic reticulum

The correct answer is: Chloroplasts

The correct answer is chloroplasts, as these organelles are specifically designed for the process of photosynthesis in plant cells. Chloroplasts contain chlorophyll, the green pigment that captures light energy, which is essential for converting carbon dioxide and water into glucose and oxygen during photosynthesis. This process not only provides energy for the plant but also contributes to the oxygen supply in the atmosphere. Mitochondria are primarily involved in cellular respiration, generating energy through the breakdown of glucose. Ribosomes are responsible for protein synthesis, translating genetic information into proteins. The endoplasmic reticulum is involved in the synthesis of lipids and proteins and plays a role in the transport of these molecules but does not participate in photosynthesis. Therefore, chloroplasts are uniquely suited for this process, making them the correct choice.