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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
Angiosperms bearing unisexual flowers are said to be either monoecious or dioecious. Explain with the help of one example each.
Draw a labelled mature stage of a dicotyledonous embryo.
Describe the formation of helobial endosperm
______ is the first cell of female gametophytic generation in angiosperms.
Identify the ploidy of embryo and endosperm respectively formed after following cross.
An angiospermic male plant with 24 chromosomes in its pollen mother cells is crossed with female plant bearing 24 chromosomes in its root cells.
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?
In dicots, the pollen grains are usually ______
A diploid female plant and a tetraploid male plant are crossed. The ploidy of endosperm shall be ______.
In angiosperms, triple fusion is required for the formation of ______.
The endosperm of gymnosperms is ______.
If the endosperm cell of an angiosperm contains 24 chromosomes, the number of chromosomes in the root tip cells will be ______.
The cells of endosperm have 24 chromosomes. What will be the number of chromosomes in the gametes?
The coconut water from tender coconut is ______
Coconut water contains:
The diagram given below shows the three types of endosperms in angiosperms.
 |
 |
 |
| Type 1 | Type 2 | Type 3 |
- Identify the three types of endosperms shown above.
- Name the type of endosperm which commonly occurs in polypetalous dicots.
The number of chromosomes in the leaf cells of a male plant is 40 and in the stem cells of a female plant is 60. If they are artificially hybridised, what will be the number of chromosomes in the endosperm?
