Enumerate the functions of tapetum.

Explanation

`**` It supplies nutrition to the developing microspores.
`**` It contributes sporopollenin through ubisch bodies thus plays an important role in pollen wall formation.
`**` The pollenkitt material is contributed by tapetal cells is later transferred to the pollen surface.
`**` Exine proteins responsible for .. rejection reaction .. of the stigma are present in the cavities of the exine. These proteins are derived from tapetal cells.