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The one advantage of cleistogamy is

  • It leads to greater genetic diversity

  • Seed dispersal is more efficient and wide spread

  • seed set is not dependent on pollinators

  • Each visit of pollinator results in the transfer of hundreds of pollen grains

C.

seed set is not dependent on pollinators

Cleistogamous flowers do not open so, they self-pollinate and thus, do not depend on pollinators.

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What is bagging technique ? How is it useful in plant breeding programmes ?
Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events ? Name the structures formed at the end of these two events.
What are chasmogamous flowers ? Can cross pollination occur in cleistogamous flowers ? Give reasons for your answer.
Mention two strategies evolved to prevent self-pollination in flowers..
What is triple fusion ? Where and how does it take place ? Name the nuclei involved in triple fusion.
Differentiate

(a) hypocotyl and epicotyl

(b) Coleoptile and coleorhiza

(c) Integument and testa

(d) Perisperm and pericarp.

With a neat labelled diagram, describe the parts of a typical angiosperm ovule.
What is meant by emasculation ? When and why does a plant breeder employ this technique ?
Arrange the following terms in a correct development sequence :
Pollen grain, sporogenous tissue, microspore tetrad, pollen mother cell, male gamete.
 What do you mean by monosporic development of female gametophyte ?
With a neat diagram explain the 7-celled, Eight nucleate mature female gametophyte.

What is self-incompatibility? Why does self-pollination not lead to seed formation in self-incompatible species?
Why do you think the zygote is dormant for some time in a fertilized ovule ?
Why is apple called a false fruit ? Which part of flower form its fruit ?
If one can induce parthenocarpy, through the application of growth substances, which fruits you would select to induce parthenocarpy and why ?
 Explain the role of tapetum in the pollen grain wall formation.
What is apomixis ? Write its importance.

Name the parts of an angiosperm flower in which development of male and female gametophyte take place.

(a) Draw a diagrammatic sectional view of a mature anatropous ovule and label the following parts in it:

(i) that develops into seed coat.

(ii) that develops into an embryo after fertilization.

(iii) that develops into an endosperm in an albuminous seed.

(iv) through which the pollen tube grains entry into the embryo sac.

(v) that attaches the ovule to the placenta.

(b) Describe the characteristic features of wind pollinated flowers.

(a) Explain the different ways apomictic seeds can develop. Give an example of each.

(b) Mention one advantage of apomictic seeds to farmers.

 (c) Draw a labelled mature stage of a dicotyledonous embryo.