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प्रश्न
Why does the zygote begin to divide only after the division of Primary endosperm cell (PEC)?
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उत्तर
The zygote needs nourishment during its development. As the mature, fertilised embryo sac offers very little nourishment to the zygote, the PEC divides and generates the endosperm tissue which nourishes the zygote. Hence, the zygote always divides after division of PEC.
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संबंधित प्रश्न
Some organisms suspend their metabolic activities to survive in unfavourable conditions. Explain with the help of any four examples.
Angiosperms bearing unisexual flowers are said to be either monoecious or dioecious. Explain with the help of one example each.
Describe the development of endosperm after double fertilisation in an angiosperm.
Draw a labelled mature stage of a dicotyledonous embryo.
Endosperm of angiosperm is __________.
(A) haploid
(B) diploid
(C) triploid
(D) tetraploid
Identify the CORRECT statement/s from the following.
i. In post-fertilization changes within the ovule, the development of embryo is followed by the development of endosperm.
ii. Helobial endosperm is intermediate between cellular and nuclear type endosperm.
iii. Helobial endosperm is mostly observed in 72 families of dicots.
At what stage of endosperm development, will you observe nuclear or cellular type of endosperm?
Ex-albuminous seeds differ from albuminous seeds in ____________.
In dicots, the pollen grains are usually ______
The endosperm of gymnosperms is ______.
The cells of endosperm have 24 chromosomes. What will be the number of chromosomes in the gametes?
Mark the odd one.
Which of the following statements are true related to Seed X and Y?
 |
 |
| SEED X | SEED Y |
- Seed X is dicot and endospermic or albuminous.
- Seed X is dicot and non-endospermic or non-albuminous.
- Seed Y is a monocot and endospermic or albuminous.
- Seed Y is a monocot and non-endospermic or non-albuminous.
Choose the correct option with the respect to the nature of the seed.
Coconut water contains:
The type of evolution where the central part is occupied by free nuclear and the peripheral part by cells is observed in ______.
In angiosperm, the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are ______.
