The term used for transfer of pollen grains from anthers of one plant to stigma of a different plant which during pollination, brings genetically different types of pollen grains to stigma, is:
Xenogamy – Transfer of pollen grains from anther to the stigma of a different plant. This is the only type of pollination which during pollination brings genetically different types of pollen grains to the stigma.
A typical angiosperm embryo sac at maturity is:
Thus, hilum represents the junction between ovule and funicle. Each ovule has one or two protective envelopes called integuments. Integuments encircle the nucellus except at the tip where a small opening called the micropyle is organised. Opposite the micropylar end, is the chalaza, representing the basal part of the ovule.
In some members of which of the following pairs of families, pollen grains retain their viability for months after release?
In some cereals such as rice and wheat, pollen grains lose viability within 30 minutes of their release, and in some members of Rosaceae, Leguminoseae and Solanaceae, they maintain viability for months.
The ovary is half inferior in:
In water hyacinth and water lily, pollination takes place by:
In a majority of aquatic plants such as water hyacinth and water lily, the flowers emerge above the level of water and are pollinated by insects or wind as in most of the land plants. Their stem part which is above the thalamus is not in the water. The pollen grains are in the upper part of thalamus so pollination can't done by water. That's why it is done by insects and wind.
What type of pollination takes place in Vallisneria?
Which one of the following, both autogamy and geitonogamy are prevented?
Autogamy and geitonogamy are two forms of self-pollination. In autogamy, pollen falls on stigma of the same flower. While in geitonogamy pollens from a flower fall on the stigma of some other flower on the same plant. Papaya is a dioecious plant thus both autogamy and geitonogamy are prevented in it.
Which of the following has proved helpful in preserving pollen as fossils?
Exine of pollen grain is made up of highly resistant fatty substance called sporopollenin, which is not degraded by any enzyme. It is not affected by high temperature, strong acid or strong alkali. Because of the sporopollenin, pollen grains are well preserved as microfossils.
Double fertilisation is
Winged pollen grains are present in
Each pollen grain of Pinus has two wing-like structures which enable it to float in the air, as an adaptation for dispersal by wind. Pollen grains of mustard, Cycas and mango are not winged.
Which of the following statements is not correct? 
So, the correct option is 'Pollen grains of many species can germinate on the stigma of a flower, but one pollen tube of the same species grow into the style'.
Which one of the following statements is not true? 
So, the correct answer is 'Tapetum helps in the dehiscence of anther.'
Filiform apparatus is characteristic feature of: [2015 RS]
The synergid cell wall forms a highly thickened structure called the filiform apparatus at the micropylar end, consisting of numerous finger-like projections into the synergid cytoplasm. It is believed to play a major role in pollen tube guidance and reception.
Which of the following are the important floral rewards to the animal pollinators? [2015 RS]
Nectar and pollen grains are the usual floral rewards which the animal pollinators get.
The hilum is a scar on the: [2015 RS]
Which one of the following statements is not true? [2015 RS]
Honey is made by nectar and pollens. Bees collect pollen and nectar in the spring when most flowers and plants are in bloom. They collect them in their stomach but an hour, the nector mixes with the proteins and enzymes produced by bees, which convert nectar into honey.
Which one of the following may require pollinators, but is genetically similar to autogamy? [2015 RS]
Male gametophyte with least number of cell is present in: 
Function of filiform apparatus is to: 
Which of the following layers in the wall of an anther nourishes the developing pollen grains?