Sexual Reproduction in Flowering Plants

In a type of apomixis known as adventive embryony, embryos develop directly from the

1. nucellus or integuments
2. zygote
3. synergids or antipodals in an embryo sac
4. accessory embryo sacs in the ovule.

Which one of the following represents an ovule, where the embryo sac becomes horse-shoe shaped and the funiculus and micropyle are close to each other?

1. Amphitropous
2. Circinotropous
3. Atropous
4. Anatropous

Through which cell of the embryo sac, does the pollen tube enter the embryo sac?

1. Egg cell
2. Persistent synergid
3. Degenerated synergids
4. Central cell

When a diploid female plant is crossed with a tetraploid male, the ploidy of endosperm cells in the resulting seed is

1. tetraploidy
2. pentaploidy
3. diploidy
4. triploidy

An ovule which becomes curved so that the nucellus and embryo sac lie at right angles to the funicle is

1. hemitropous
2. campylotropous
3. anatropous
4. orthotropous.

Anthesis is a phenomenon which refers to

1. reception of pollen by stigma
2. formation of pollen
3. development of anther
4. opening of flower bud.

In a flowering plant, archesporium gives rise to

1. only the wall of the sporangium
2. both wall and the sporogenous cells
3. wall and the tapetum
4. only tapetum and sporogenous cells.

In angiosperms pollen tubes liberate their male gametes into the

1. central cell
2. antipodal cells
3. egg cell
4. synergids

In angiosperms all the four microspores of tetrad are covered by a layer which is formed by

1. pectocellulose
2. callose
3. cellulose
4. sporopollenin

What is the direction of micropyle in anatropous ovule?

1. Upwards
2. Downward
3. Right
4. Left