Advertisements
Advertisements
प्रश्न
Explain the post-pollination events leading to seed production in angiosperms.
Advertisements
उत्तर
Pollination is the process of transfer of pollen grains from anther to stigma.
-
When the pollen grains fall on the stigma, the pollen tube enters one of the synergids and releases two male gametes.
-
One of the male gametes moves towards the egg cell and fuses with it to form zygote.
-
The other male gamete fuses with the two polar nuclei and forms the primary endosperm nucleus. This is termed as triple fusion.
-
After the triple fusion, the central cell becomes the primary endosperm cell (PEC).
-
The primary endosperm nucleus gives rise to endosperm, while the zygote develops into embryo.
- Seeds are the fertilised ovules that are developed inside a fruit.
- The integuments of ovules harden to form the seed coat, and the micropyle facilitates the entry of oxygen and water into the seed.
APPEARS IN
संबंधित प्रश्न
As a senior biology student you have been asked to demonstrate to the students of secondary level in your school, the procedure(s) that shall ensure cross-pollination in a hermaphrodite flower. List the different steps that you would suggest and provide reasons for each one of them.
Name of the parts of the ovary which give rise to:
Fruit wall ______
Give an account of any two biotic agents for pollination along with their adaptations.
Wind pollination is common in ______.
A botanist studying Viola (common pansy) noticed that one of the two flower types withered and developed no further due to some unfavorable condition, but the other flower type on the same plant survived and it resulted in an assured seed set. Which of the following will be correct?
Which type of pollination does the figure indicate?
Which of the following floral adapation are adapted by hydrophilous flowers?
Describe any three adaptations in hydrophilous flowers.
What is epihydrophily?
Give any four floral adaptations for chiropterophily.
