$$ \text { Identify the type of carpel with the help of diagrams given below } $$
(a) If a gynoecium has multiple carpels fused into a single structure, it is syncarpous. In this given diagram, the type of carpel is syncarpous (e.g., poppy).
If a gynoecium has multiple carpels in free form, it is apocarpous. In this given diagram, the type of carpel is apocarpous. (e.g., michelia)
How is pollination carried out in water plants?
(a) In many aquatic plants with emergent flowers, pollination occurs by wind and insects.
(b) In water plants if pollination occurs below the surface of water is called hypohydrophilly, e.g., Ceratophyllum.
(c) In water plants if pollination takes place over the surface of water is called epihydrophily, e.g., Vallisneria spiralis.
What is the function of the two male gametes produced by each pollen grain in angiosperms.
One male gamete unites with egg forming embryo. This process is called fertilisation or syngamy.
Another male gamete unite with two polar nuclei resulting in the formation of endosperm triple fusion.
List three strategies that a bisexual chasmogamous flower can evolve to prevent self-pollination (autogamy).
A bisexual chasmogamous flower can evolve the following (three) strategies to prevent self-pollination (autogamy).
(a) Dichogamy In this mechanism, pollen release and stigma receptivity are not synchronised. In sunflower, the pollen is released before the stigma becomes receptive (protandry). In Datura, Solanum, the stigma becomes receptive much before the release of pollen (protogyny) leads to cross-pollination.
(b) Herkogamy The male and female sex organs are placed at different positions or in different directions is called Herkogamy. In these plants, the pollen cannot came in contact with the stigma of the same flower. It has undergone cross pollination, e.g., Hibiscus, Gloriosa.
(c) Self-sterility It is a genetic mechanism which prevents the self-pollen from fertilising the ovules by inhibiting pollen germination or pollen tube growth in the pistil, e.g., Abotilon.
Given below are the events that are observed in an artificial hybridisation programme. Arrange them in the correct sequential order in which they are followed in the hybridisation programme (a) Re-bagging (b) Selection of parents (c) Bagging (d) Dusting the pollen on stigma (e) Emasculation (f) Collection of pollen from male parent.
The correct sequential order of artificial hybridisatian is as following
(a) Selection of parents.
(b) Emasculation (removal of anthers from the flower bud before the anther dehisces).
(c) Bagging (process to cover the emasculated flower with a bag made up of butter paper).
(d) Collection of pollen from other male plant.
(e) Dusting of pollen on stigma.
(f) Re-bagging