Difference between C3 and C4 Plants (C3 Plants vs C4 Plants)

C₃ plants: The plants exhibiting C3 pathway are called C3 plants. About 95% of the plants on earth are C3 plants.

C₄ plants: The plants exhibiting  C4 pathway are called C4 plants. C₄ plants live in hot moist or arid and nonsaline habitats. It occurs in grasses, sugar cane, maize, sorghum, Amarathus and Atriplex. C₄ cycle is the alternate pathway of Calvin cycle (C₃ cycle) taking place during dark phase of photosynthesis. In the C₄ cycle the first stable compound is a 4 carbon compound, namely oxaloacetic acid. Hence it is called C₄ cycle.  The C₄ plants show  a specific type of leaf anatomy (Krans anatomy). C₄ plants are more efficient in photosynthesis than the C₃ plants.

C₃ Plants vs C₄ Plants

C₃ plants
1. The leaves do not possess Krans Anatomy.
2. Chloroplasts do not have peripheral reticulum.
3. Chloroplasts are of one type (monomorphic).
4. Bundle sheath cells usually do not contain Chloroplasts.
5. In higher plants, operating C₃ cycle, the chloroplasts are all granal and have both the photosystem I and II.
6. Mesophyll cells perform complete photosynthesis.
7. Perform photosynthesis only when stomata are open.
8. C₃ plants are less efficient in photosynthesis.

C₄ plants
1. The leaves have Krans Anatomy.
2. Chloroplasts  have peripheral reticulum.
3. Chloroplasts are of types dimorphic).
4. Bundle sheath cells usually possess prominent Chloroplasts.
5. There are two types of chloroplasts, granal in mesophyll cells and agranal in bundle sheath cells. They lack photosystem II.
6. Mesophyll cells perform only initial fixation.
7. Perform photosynthesis even when stomata are closed.
8. C₄ plants are more efficient in photosynthesis.

Learn more: Comparison of C3, C4 and CAM plants