Endosperm is the part of seed that acts as a food reservoir for the developing plants.
It is the tissue of the seed.
Endosperm is of three types: nuclear, cellular and helobial
Free Nuclear Endosperm can be defined as the primary endosperm that gives rise to free nuclei that remain as a peripheral layer and a large central vacuole appears in the embryo sac.
Cellular Endosperm can be defined as the endosperm formed in the first and then other divisions of primary endosperm and is accompanied by wall formation.
Final Answer:
Hence the above given sentences define the endosperm and its types.