NEET BIOLOGY

Detailed explanation-1: -In Opuntia, the stem is modified into a flattened green structure to perform the functions of leaves, (i.e., photosynthesis). Cite some other examples of modifications of plant parts for the purpose of photosynthesis.

Detailed explanation-2: -Phylloclade is also a type of stem modification where the flattened leaf-like structures are formed, which helps in photosynthesis, examples are cactus opuntia.

Detailed explanation-3: -So function of photosynthesis in Opuntia plant is performed by stem which is thick fleshy and flattened structure containing chlorophyll and stores food. It is known as phylloclade. Sometimes, the stem, i.e., about one internode long modifies into a leaf like structure to carry out photosynthesis, as in Asparagus.

Detailed explanation-4: -Opuntia is a xerophytic plant, in which leaves are modified into spine to reduce the rate oftranspiration and they do not perform the photosynthesis at all. So function of photosynthesis in Opuntia plant is performed by stem which is thick fleshyand flattened structure containing chlorophyll and stores food.