Advertisements
Advertisements
प्रश्न
In the diagram given below, show the path of a pollen tube from the pollen on the stigma into the embryo sac. Name the components of egg apparatus.
उत्तर
Following compatible pollination, the pollen grain germinates on the stigma to produce a pollen tube through one of the germ pores. The contents of the pollen grain (2 mole nuclei) move into the pollen tube. Pollen tube grows through the tissues of the stigma and reaches the ovary. After reaching the ovary, pollen tube, enters the ovule through the micropyle and then enters the embryo sac by passing into one of the synergids through the filiform apparatus. It leads to the degeneration of that synergid.
The pollen tube breaks to release its contents (2 male nuclel). Out of the two male gametes one fuses with egg and the other fuses with central cell and fertilise.
Longitudinal section of a flower showing growth of pollen tube
The component cells of the egg-apparatus in an embryo sac include, two synergids one egg cell and the filiform apparatus.
A diagrammatic representation of the mature embryo sac
APPEARS IN
संबंधित प्रश्न
Describe any two devices in a flowering plant which prevent both autogamy and geitonogamy.
Explain the Following Term:
Ornithophily
Explain the following term:
Elephophily
What is a fruit?
Match the following
| I) | External fertilization | i) | pollen grain |
| II) | Androecium | ii) | anther wall |
|
III) |
Male gametophyte | iii) | algae |
| IV) | Primary parietal layer | iv) | stamens |
Identify the incorrect pair
The correct order of haploid, diploid, and triploid structure in fertilized embryo sac is
Transmitting tissue is found in
What is polyembryony? How it can commercially exploited.
Write a short note on Heterostyly.
By which of the following double fertilization is exhibited?
Identify the function of filiform apparatus.
If the cells of the nucellus in the angiosperm ovule contain 24 chromosomes, then ____________ chromosomes will be present in the endosperm of a self-pollinated flower.
Double fertilisation was first discovered in 1898 by ______ in Fritillaria and Lilium.
Fusion of one of the male gametes with egg nucleus is referred to as ______.
Find out the CORRECT sequence of events taking place in pollen - pistil interaction.
- Pollen tube enters one of the synergids and bursts to release male gametes.
- Pollen tube enters the ovule through the micropyle of the ovary.
- The pollen tube grows through the stigmatic tissue and then style.
- Pistil recognizes the correct pollen and accepts it.
Which is the triploid tissue in a fertilised ovule? How is the triploid condition achieved?
Identity the part of embryo sac which takes part in formation of primary endosperm nucleus during fertlisation
Give a term for the following:
Fusion of male gamete and secondary nucleus in angiosperms.
