91.

Double fertilization occurs in

• Riccia

• Pteridium

• Cycas

• Capsella

In gymnosperms, the pollen chamber represents

• A cell in the pollen grain in which the sperms are formed

• A cavity in the ovule in which pollen grains are stored after pollination

• An opening in the megagametophyte through which the pollen tube approaches the egg

• The microsporangium in which pollen grains develop

Ubisch bodies are present in

• pollen tube

• pollen grain

• microspore

• tapetum

In Cycas, pollination takes place in

• 3- celled stage

• 4- celled stage

• 2- celled stage

• 1- celled stage

In Pinus, male cone bears a large number of

• ligules

• anthers

• micro- sporophylls

• mega- sporophylls

Cleavage polyembryony occurs in

• Pinus

• Mini Cycas

• Cycas

• Ephedra

In Cycas, pollination takes place in

• 3- celled stage

• 4- celled stage

• 2- celled stage

• 1- celled stage

Nucellus forms which of the following part of fruit?

• Seed coat

• Perisperm

• Seed

• Raphe

Growth of pollen tube towards embryo sac is

• geotropism

• thigmotaxis

• chemotaxis

• All of these

Perisperm is

• degenerate part of synergids

• peripheral part of endosperm

• degenerate part of secondary nucleus

• remnant of nucellus