Pollen grains are able to withstand extremes of temperature and dessication because their exine is composed of

(1) cutin

(2) suberin

(3) sporopollenin

(4) callose

During formation of which of the following free nuclear division occurs?

(1) Flower

(2) Endosperm

(3) Gametes

(4) Fruit

The pollen tube usually enters the embryo sac

(1) through one of the synergids

(2) by directly penetrating the egg

(3) between one synergid and central cell

(4) by knocking off the antipodal cells

Edible part of apple is the

(1) thalamus

(2) mesocarp

(3) epicarp

(4) endocarp

Seed of castor is

(1) non-endospermic, exalbuminous

(2) endospermic albuminous

(3) endospermic exalbuminous

(4) non-endospermic albuminous.

Ubisch bodies are secreted from

(1) ovule

(2) tapetum

(3) both of these

(4) none of these

Aleurone layer is

(1) haploid

(2) diploid

(3) triploid

(4) tetraploid

Pollination by bat is called

(1) ornithophily

(2) chitopteriphily

(3) malacophily

(4) anemophily

Xenia and metaxenia terms are related with

(1) pollen culture

(2) xylem and phloem

(3) endosperm

(4) embryo