What is sporopollenin?

Which one of the following statements is not true regarding sporopollenin?

State the significance of sporopollenin.

Which of the following statements about sporopollenin is false ?

Assertion : Sporopollenin preserves pollen in fossil deposits. Reason : Sporopollenin is resistant to physical and biological decomposition

Assertion : Exine of a pollen grain is made up of sporopollenin which is resistant to high temperature, strong acid or alkali as well as enzymatic degradation. Reason : Sporopollenin is absent in the region of germ pores.

Read the given statements. (i) Outer exine is made up of sporopollenin. (ii) Inner intine is pecto-cellulosic in nature (iii) Generative cell is bigger and contains abundant food reserve (iv) Vegetative cell is small and floats in the cytoplasm of the generative cell. Which of the given statements are not true regarding structure of pollen grain?

What is siphonostele? What are the different types of siphonostele?