An example of a seed with endosperm, perisperm and caruncle is
Cotton
coffee
lily
lily
Which one of the flowing pairs of plants structures has haploid number of chromosomes?
Megaspore mother cell and antipodal cells
Egg cell and antipodal cells
Nucellus and antipodal cells
Nucellus and antipodal cells
Unisexuality of flowers prevents
autogamy, but not geitonogamy
Both geitonogamy and xenogamy
geitonogamy, but not xenogamy
geitonogamy, but not xenogamy
A.
autogamy, but not geitonogamy
The transfer of pollen from the anther to stigma is called pollination. Autogamy also called self-pollination involves the transfer of pollen grains on one flower to the stigma of the same flower. Self-pollination occurs only in bisexual or hermaphrodite flowers.
Geitonogamy involves the transfer of pollen grains from a male flower to the stigma of the female flower of the same plant. Thus, geitonogamy operates only in monoecious plants ie, the plants having male and female flowers on different places.
Allogamy or xenogamy knew as cross-pollination involves the transfer of pollen grains of the male flower to the stigma of the gentically different female flower. It takes place via, various agencies like wind, water, insects etc.
What does the filiform apparatus do at the entrance into ovule?
It helps in the entry of pollen tube into a synergid
It prevents entry of more than one pollen tube into the embryo sac
It brings about opening of the pollen tube
It brings about opening of the pollen tube
Importance of day length in flowering of plants was first shown in
Lemna
tobacco
Cotton
Cotton
Male gametes in angiosperms are formed by the division of
microspore
generative cell
vegetative cell
vegetative cell
Which one of the following is surrounded by a callose wall?
Microspore mother cell
Male gamete
Egg
Egg
Parthenocarpic tomato fruits can be produced by
Removing androecium of flowers before pollen grains are released
Treating the plants with low concentrations of gibberellic acid and auxins
Raising the plants from vernalized seeds
Raising the plants from vernalized seeds
Long filamentous threads protruding at the end of a young cob of maize are
anthers
styles
ovaries
ovaries
Conifers differ from grasses in the
production of seeds from ovules
lack of xylem tracheids
absence of pollen tube
absence of pollen tube