Chlorenchyma and aerenchyma are modified/specialized parenchyma tissues.

Parenchyma is a simple permanent tissue that is found in all parts of the plant body. It is the most abundant and versatile tissue in plants. It performs various functions such as photosynthesis, storage, secretion, and support.

Chlorenchyma:

Chlorenchyma is a specialized parenchyma tissue that contains chloroplasts. It is found in the mesophyll of leaves, where it performs photosynthesis. The cells of chlorenchyma are thin-walled, elongated, and closely packed. They have large intercellular spaces that facilitate the exchange of gases. The chloroplasts in chlorenchyma cells contain chlorophyll, which is necessary for photosynthesis. The cells of chlorenchyma are rich in cytoplasm, making them capable of producing and storing food.

Aerenchyma:

Aerenchyma is a specialized parenchyma tissue that has large air spaces. It is found in the roots and stems of aquatic plants and plants growing in waterlogged soils. The large air spaces in aerenchyma tissues provide buoyancy to the plant, allowing it to float on water. They also facilitate the exchange of gases between the roots and the atmosphere. The cells of aerenchyma are elongated and have thin walls. They are arranged in such a way that large air spaces are formed between them. The large air spaces in aerenchyma tissues are filled with air, which helps in the respiration of the roots.

Conclusion:

Chlorenchyma and aerenchyma are specialized parenchyma tissues that perform specific functions in plants. While chlorenchyma is involved in photosynthesis, aerenchyma provides buoyancy and facilitates gas exchange in aquatic plants and plants growing in waterlogged soils.