In over 60 per cent of angiosperms, pollen grains are shed at cell 2-celled stage. In the remaining species the generative cell divides mitotically to give rise to the two male gametes before pollen grains are shed (3-celled stage.)

Correct Option: A

In over 60 per cent of angiosperms, pollen grains are shed at cell 2-celled stage. In the remaining species the generative cell divides mitotically to give rise to the two male gametes before pollen grains are shed (3-celled stage.)

The germ pores are apertures in the exine layer of the pollen grain where the sporopollenin is absent. The germ pore helps in the formation of the germ tube or pollen tube and which makes its exit on germination.

Correct Option: C

The germ pores are apertures in the exine layer of the pollen grain where the sporopollenin is absent. The germ pore helps in the formation of the germ tube or pollen tube and which makes its exit on germination.

Cleistogamous flower produce assured seed set even in the absence of pollinations. Plants such as Viola, Oxalis and Commelina.

Correct Option: A

Cleistogamous flower produce assured seed set even in the absence of pollinations. Plants such as Viola, Oxalis and Commelina.

Sporopollenin is fatty substance present in pollen wall and provides resistance against extremes conditions like high temperature, acid, bases.

Correct Option: B

Sporopollenin is fatty substance present in pollen wall and provides resistance against extremes conditions like high temperature, acid, bases.

Papaya is dioecious i.e. male and female flowers occurs in separate plants so that it prevents both autogamy & geitonogamy (method of self pollination).

Correct Option: A

Papaya is dioecious i.e. male and female flowers occurs in separate plants so that it prevents both autogamy & geitonogamy (method of self pollination).