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प्रश्न
Explain the different types of endosperms in angiosperms.
Explain the development of the different types of endosperms in angiosperms.
Describe types of endosperm.
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उत्तर
- Free-nuclear endosperm: This is the most common type. The primary endosperm nucleus divides repeatedly without cell wall formation, and the resulting nuclei remain free in the cytoplasm. Later, walls may form around the nuclei.
Example: Coconut water. - Cellular endosperm: Each nuclear division is immediately followed by cell wall formation, so the endosperm becomes cellular from the very beginning.
Examples: Peperomia, Villarsia, Drimys. - Helobial endosperm: This type is intermediate between the free-nuclear and cellular types. The first division of the primary endosperm nucleus is followed by a cell wall formation that separates the endosperm into a large micropylar chamber and a small chalazal chamber.
Examples: Vallisneria, Erimus.
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संबंधित प्रश्न
Sketch and label stages in the development of the angiospermic female gametophyte from the functional megaspore.
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Read the statement and answer the questions that follow.
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(a) What could have prevented the rest of the 40 ovules from maturing into viable seeds? Explain giving a reason.
(b) Describe the development of a dicot embryo in a viable seed.
(c) Why certain angiospermic seed albuminous while others are exalbuminous? Explain.
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Define Racemose inflorescence
Name a plant which flowers every twelve years.
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Pollen grains of wind-pollinated flowers are produced in large quantities.
Fragrant flowers with well developed nectaries are an adaptation for ______.
The flower is the site of ______.
Pollen grains are well preserved as fossils because of the presence of ______
In a fertilized ovule, n, 2n, and 3n conditions occur respectively in ______
Angiosperms have dominated the land flora primarily because of their ______.
Place the following groups of plants in order, beginning with those that first appeared on the earth and progressing toward those that appeared most recently in time.
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Which of the following statement is incorrect?
The flower is a highly modified and condensed reproductive shoot specially meant for ______
Male and female reproductive structures of the angiosperms are ______.
Match List I with List II:
| List I (Types of Stamens) |
List II (Example) |
||
| A. | Monoadelphous | I. | Citrus |
| B. | Diadelphous | II. | Pea |
| C. | Polyadelphous | III. | Lily |
| D. | Epiphyllous | IV. | China-rose |
Choose the correct answer from the options given below:
