Question

The site of Calvin cycle is
A. Chloroplast
B. Cytoplasm
C. Mitochondria
D. Glyoxysomes

Answer 1

Calvin cycle is the process of fixation of Carbon dioxide into sugar by photosynthetic plants and algae. Chloroplasts are organelle found in plants and are responsible for carbon fixation.

Complete answer:
Option A: Chloroplasts are double-membrane organelle found in photosynthetic plants. They have photosynthetic pigment molecules in them which harvest energy from sunlight and use it to fix the atmospheric carbon dioxide into sugar molecules. The process is carried out through a cycle of chemical reactions known as the Calvin cycle. The inner space of chloroplasts is known as stroma and the Calvin cycle takes place here. Therefore this is the correct answer.

Option B: Cytoplasm is the matrix inside the cells. Every cell has a cytoplasm and the nucleus and organelle float in the cytoplasm. But the Calvin cycle needs a specialized structure to Carry out the reactions. Therefore, this is the incorrect option.
Option C: Mitochondria are double-membrane organelle found in eukaryotic cells. They are known as the powerhouse of cells and are responsible for the synthesis of the energy currency of the cells, ATP. Therefore, this is the incorrect option.
Option D: Glyoxysomes are single membrane-bound organelle found in plants and fungi. They are found in the fast storage tissue of plants and contain enzymes that can participate in the metabolism of fat. Therefore, this is the incorrect option.

Hence, the correct answer is option (A)

Note: The Calvin cycle is known as a light-independent reaction as they don't directly use light energy. In the previous step known as light reactions, the light energy gets converted into ATP, and the Calvin cycle uses this ATP. Light reactions occur in the thylakoids of Chloroplasts.