Write the functions of the following
(a) Centromere (b) Cell wall
(c) Smooth ER (d) Golgi apparatus
(e) Centrioles

Explanation

(a) Centromere : If is required for proper division of chromosome, centromere possesses two baby chromosomes. It functions during cell division for connection of spindle fibre with chromosomes.

(b) Cell wall : It gives definite shape to cell. It also protects the cell from mechanical injury or infection. It helps in cell to cell interaction and provides barrier to undesirable macro molecules.
(c) Smooth ER : It helps in synthesis of lipids, metabolism of carbohydrates, and in concentration of Ca++. It helps in detoxi fication of medicines and in attachment of receptor materials.
For diagram see section-A, Q. No. 16.
(d) Golgi apparatus : It forms Glyco protein and Glycolipid. It synthesizes required material for cell wall. It helps in formation of cellular disc during cell division.
For diagram see section-A, Q. No. 17.
(e) Centriole : It forms basal bodies of cilia and flagella. It forms spindle fibres. Spindle fibres help in tail formation of sperm cells in animal cells during cell division. Forms centre rays and helps in cell division. Which acts as spindle pole.