Chloroplasts in Bundle Sheath Cells of C4 Plants

C4 plants are a type of plants that have a special mechanism for photosynthesis. Unlike C3 plants, they have a unique biochemical pathway that involves the initial fixation of CO2 into a four-carbon compound called oxaloacetate, which is then transported to bundle sheath cells where it is decarboxylated to release CO2 for the Calvin cycle. This process occurs in specialized cells called mesophyll cells and bundle sheath cells.

Chloroplasts are the organelles responsible for photosynthesis in plants. They contain a pigment called chlorophyll that absorbs light energy and converts it into chemical energy that is used to produce glucose. In C4 plants, chloroplasts are present in both mesophyll cells and bundle sheath cells, but their distribution and organization are different from that of C3 plants.

Bundle Sheath Cells in C4 Plants

Bundle sheath cells are specialized cells that surround the vascular tissue in leaves. They are located in the inner layer of the leaf and play a critical role in the C4 pathway of photosynthesis. Bundle sheath cells are characterized by their dense cytoplasm, large nuclei, and numerous chloroplasts. They are arranged in a concentric pattern around the vascular tissue, with a layer of mesophyll cells surrounding them.

Chloroplasts in Bundle Sheath Cells of C4 Plants

The chloroplasts in bundle sheath cells of C4 plants are different from those in C3 plants. They are smaller, more numerous, and contain fewer grana. Grana are stacks of thylakoid membranes that contain the photosynthetic pigments. The chloroplasts in bundle sheath cells of C4 plants also have fewer stroma thylakoids, which are thylakoids that are not organized into grana.

The chloroplasts in bundle sheath cells of C4 plants are adapted to the unique requirements of the C4 pathway. They have a low photosystem II to photosystem I ratio, which helps to reduce photorespiration. They also have a higher ratio of PSI to PSII, which is necessary for efficient cyclic electron flow. The chloroplasts in bundle sheath cells of C4 plants also have a smaller antenna size, which reduces the risk of photodamage.

In conclusion, chloroplasts are present in bundle sheath cells of C4 plants. They are adapted to the unique requirements of the C4 pathway and have a different organization and distribution compared to those in C3 plants. The chloroplasts in bundle sheath cells of C4 plants play a critical role in the efficient use of light energy and the reduction of photorespiration.

In C4 plants photorespiration is absent there's double
carboxylation and the chloroplast is located in bundle sheath cells. This is one of the characteristics of c4 plants. option B is correct.