Autogamy refers to pollination achieved within the same flower. Which condition is essential for autogamy to be successful?
Autogamy requires synchrony in pollen release and stigma receptivity and also, the anthers and the stigma should lie close to each other.
Question 222 of 501
📘 CLASS XII
Which of the following plants produce both chasmogamous (open) and cleistogamous (closed) flowers?
Plants such as Viola (common pansy), Oxalis, and Commelina produce two types of flowers: chasmogamous and cleistogamous.
Question 223 of 501
📘 CLASS XII
What is a significant advantage of cleistogamy for a plant?
Cleistogamous flowers are invariably autogamous as there is no chance of cross-pollen landing on the stigma. They produce assured seed-set even in the absence of pollinators.
Question 224 of 501
📘 CLASS XII
Geitonogamy is genetically similar to autogamy because:
Geitonogamy is functionally cross-pollination involving a pollinating agent, but genetically it is similar to autogamy since the pollen grains come from the same plant.
Question 225 of 501
📘 CLASS XII
Which type of pollination guarantees the introduction of genetically different types of pollen grains to the stigma?
Xenogamy involves the transfer of pollen grains from the anther to the stigma of a different plant. This is the only type of pollination which brings genetically different types of pollen grains to the stigma.
Question 226 of 501
📘 CLASS XII
Wind-pollinated flowers are characterized by which of the following features?
Wind pollination requires that pollen grains are light and non-sticky. Flowers often possess well-exposed stamens and large feathery stigma.
Question 227 of 501
📘 CLASS XII
In the context of wind pollination, what do the "tassels" or "ears" of a corn cob represent?
The ears (tassels) of the corn cob are nothing but the stigma and style which wave in the wind to trap pollen grains.
Question 228 of 501
📘 CLASS XII
Pollination by water is rare in flowering plants. Which set of plants represents examples of water-pollinated species?
Some examples of water pollinated plants are Vallisneria and Hydrilla (fresh water) and Zostera (marine seagrass). Water hyacinth and Water lily are insect/wind pollinated.
Question 229 of 501
📘 CLASS XII
How does pollination occur in Vallisneria?
In Vallisneria, the female flower reaches the surface of water by the long stalk and the male flowers or pollen grains are released on to the surface of water.
Question 230 of 501
📘 CLASS XII
In seagrasses like Zostera, how is pollination achieved?
In seagrasses, female flowers remain submerged in water and the pollen grains are released inside the water. Pollen grains are long, ribbon-like and carried passively.
