Select the true statements for pollen grain:

(i) The pollen grains represent the male gametophytes.

(ii) It has a prominent two-layered wall.

(iii) The hard-outer layer called the exine is made up to sporopollenin which is one of the most resistant organic material known.

(iv) Pollen grain exine has prominent apertures called germ pores where sporopollenin, cellulose and pectin is absent.

(v) Pollen grains are well preserved as fossils because of the presence of cellulose and pectin.

(vi) The inner wall of the pollen grain is called the intine which made up of cellulose and pectin.