Theory:

  • The nucellus is the essential part of the ovule, surrounded by two integuments and has a micropyle opening.
  • A stalk known as the funiculus connects the ovule to the ovary wall.
  • Chalaza is the basal part.
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Anatropous ovule
Embryo sac:
Embryosac-en.svg.png
Structure of embryo sac
  
The embryo sac of the ovule contains \(7 \)cells and \(8 \)nuclei located within the nucellus.
  • Out of the seven cells, three cells are located at the micropylar end and form the egg apparatus.
  • The remaining three cells are at the chalaza end form the antipodal cells.
  • The remaining two nuclei are called polar nuclei and are present at the centre.
  • In the egg apparatus, one forms the female gamete or egg cell, and the remaining two cells are the synergids.
Process of sexual reproduction in flowering plants involves two processes:
  • Pollination
  • Fertilization
Pollination and its types:
The transfer of pollen grains from the anther to the stigma of a flower is called pollination.
Types of pollination:
 
Pollination is of two types. They are:
  1. Self-pollination
  2. Cross pollination
Pollination.png
 
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Types of pollination
 
Importance of pollination:
  • It leads to fertilization which results in the formation if fruits and seeds.
  • As a result of pollination new varieties of plants are formed by the combination of genes (in cross pollination).
Reference:
https://commons.wikimedia.org/wiki/File:Embryosac-en.svg
https://commons.wikimedia.org/wiki/File:Ovule_morphology_anatropous.svg