Question

What is the function of tapetum in a developing anther ?
(a) To draw food material from microspores
(b) To digest the sporophytes.
(c) To supply food materials to the developing microsporocytes.
(d) To give protection to inner tissues.

Answer 1

Hint: Tapetum is the innermost layer of anther wall which surrounds the sporogenous tissue. The tapetal cells help in the subsistence of maturing pollen grains. They play a major role in the development of pollen grains.

Complete answer:
A tapetum is the innermost layer of anther wall which surrounds the sporogenous tissue. Tapetal cells nourish the developing pollen grains/Microsporocytes. It also acts as a source of the precursor of the pollen coat. The cells of tapetum possess dense cytoplasm and generally have more than one nucleus i.e. multinucleate. They are polyploid and are usually bigger. The tapetal cells show an increase in the DNA content.
The anther wall layers consist of the following layer: - Epidermis - Endothecium - Middle layer - Tapetum. The two main types of tapetum are secretory or glandular tapetum and amoeboid/plasmodium tapetum. - Secretary tapetum secretes sporopollenin, pollen Kitt, and compatibility proteins. These cells provide Ubisch bodies that help in the ornamentation of the exine. - Amoeboid tapetum: Cells undergo breakdown and their entire protoplasts move towards the center to nourish the pollen grain.

So, the answer is, ‘To supply food materials to the developing microsporocytes.’

Note:
An increase in DNA content of tapetum may be achieved by the following ways: - Endomitosis: It involves DNA replication and the splitting of chromosomes. - Restitution nucleus: It involves normal mitosis up to anaphase but the chromosomes at two poles get surrounded by a common nuclear membrane. - Polyteny: If DNA replication is not accompanied by the splitting of chromosomes polytene chromosomes are formed. Pollen Kitt is a sticky and sugary substance made up of lipids and starch which is also known as pollen coat. It helps the pollen to stick to the bugs.