In angiosperms, the correct sequence of events leading to the formation of female gametophyte in the ovule is:
A.
3 successive free nuclear divisions in functional megaspore.
B.
Degeneration of 3 megaspores
C.
Meiotic division in megaspore mother cell
D.
Migration of 3 nuclei towards each pole.
E.
Formation of a wall resulting in seven celled embryosac.
Choose the correct answer from the options given below:
1.
(A), (B), (C), (D), (E)
2.
(C), (E), (A), (D), (B)
3.
(B), (C), (A), (D), (E)
4.
(C), (B), (A), (D), (E)
Subtopic: Â Pistil: Ovule |Â Pistil: Female Gametophyte |
 76%
From NCERT
NEET - 2023
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Select the incorrect match.
1. Zygote \(\xrightarrow[\text{into}]{\text{develops}}\) Embryo
2. Ovules \(\xrightarrow[\text{into}]{\text{develop}}\) Seeds
3. Ovary \(\xrightarrow[\text{into}]{\text{develops}}\) Fruit
4. Integument \(\xrightarrow[\text{into}]{\text{develops}}\) Fruit wall
1. Zygote \(\xrightarrow[\text{into}]{\text{develops}}\) Embryo
2. Ovules \(\xrightarrow[\text{into}]{\text{develop}}\) Seeds
3. Ovary \(\xrightarrow[\text{into}]{\text{develops}}\) Fruit
4. Integument \(\xrightarrow[\text{into}]{\text{develops}}\) Fruit wall
Subtopic: Â Fruit |
 82%
From NCERT
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Given below are two statements:
| Assertion (A): | Pollen grains of flowering plants can be well preserved as fossils. |
| Reason (R): | Hard outer layer of pollen grains is made up of most resistant, non degradable organic material called as sporopollenin. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Stamen: Male Gametophyte |
 92%
From NCERT
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Given below are two statements:
| Assertion (A): | At maturity, a typical angiospermic embryo sac is 7 celled 8-nucleated structure. |
| Reason (R): | There is a characteristic distribution of the cells within the embryo sac of the angiosperms. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Pistil: Ovule |
 51%
From NCERT
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Given below are two statements:
| Assertion (A): | Cleistogamous flowers are invariably autogamous. |
| Reason (R): | Cleistogamous flowers never expose their sex organs, so there is no chance of cross pollination in these flowers. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Pollination & Outbreeding Devices |
 90%
From NCERT
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Given below are two statements:
| Assertion (A): | Some species of Asteraceae and grasses have evolved special mechanism to produce seeds without fertilisation called as apomixis. |
| Reason (R): | Apomixis is a form of asexual reproduction that mimics sexual reproduction. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Apomixis & Polyembryony |
 55%
From NCERT
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Given below are two statements:
| Assertion (A): | Cultivation of hybrids has tremendously increased the productivity. |
| Reason (R): | If hybrids are made into apomicts, there is segregation of characters in the hybrid progeny.- |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Apomixis & Polyembryony |
 59%
From NCERT
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Given below are two statements:
| Assertion (A): | Pollen grains are not rich in nutrients. |
| Reason (R): | Pollen consumption does not increase the performance of athletes and race horses. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Stamen: Male Gametophyte |
 93%
From NCERT
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Given below are two statements:
| Assertion (A): | Pollen grains represent the male gametophytes. |
| Reason (R): | The cell wall of pollen grain is called sporoderm. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Stamen: Male Gametophyte |
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Given below are two statements:
| Assertion (A): | Wind pollinated flowers have large feathery stigma to trap pollen grains. |
| Reason (R): | Wing pollination is common in plants like Amorphophallus and Yucca. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
Subtopic: Â Pollination & Outbreeding Devices |
 76%
From NCERT
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