Which one of the following statements is correct?
1.
Cleistogamous flowers are always autogamous
2.
Xenogamy occurs only by wind pollination
3.
Chasmogamous flowers do not open at all
4.
Geitonogamy involves the pollen and stigma of flowers of different plants
Subtopic: Â Pollination & Outbreeding Devices |
 86%
From NCERT
NEET - 2013
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Which of the following statements is correct?
| 1. | Sporopollenin can be degraded by enzymes |
| 2. | Sporopollenin in made up of inorganic materials |
| 3. | Sporopollenin can withstand high temperatures as well as strong acids and alkalis |
| 4. | Sporopollenin can withstand high temperatures but not strong acids |
Subtopic: Â Stamen: Male Gametophyte |
 91%
From NCERT
NEET - 2013
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Adventive embryony is a type of apomixis where the embryos are derived directly from:
1. Nucellus or integument
2. Zygote
3. Synergids of antipodals of embryo sac
4. Accessory embryo sac in the ovule
1. Nucellus or integument
2. Zygote
3. Synergids of antipodals of embryo sac
4. Accessory embryo sac in the ovule
Subtopic: Â Embryo |
 66%
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Regarding a typical monosporic embryosac in the angiosperms:
I: Three cells are grouped together at the micropylar end and constitute the egg apparatus.
II: The egg apparatus, in turn, consists of two antipodals and one egg cell.
III: The antipodals have special cellular thickenings at the micropylar tip called filiform apparatus, which play an important role in guiding the pollen tubes into the synergid.
IV: Three cells are at the chalazal end and are called the Synergids.
1. Only I is correct
2. Only I and IV are correct
3. Only II and III are correct
4. Only III is correct
I: Three cells are grouped together at the micropylar end and constitute the egg apparatus.
II: The egg apparatus, in turn, consists of two antipodals and one egg cell.
III: The antipodals have special cellular thickenings at the micropylar tip called filiform apparatus, which play an important role in guiding the pollen tubes into the synergid.
IV: Three cells are at the chalazal end and are called the Synergids.
1. Only I is correct
2. Only I and IV are correct
3. Only II and III are correct
4. Only III is correct
Subtopic: Â Monocarpic & Polycarpic |Â Pistil: Ovule |Â Pistil: Female Gametophyte |
 74%
From NCERT
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Match each item in Column I with one in Column II and select the correct match from the codes given:
Codes:
| COLUMN I | COLUMN II | ||
| A | Ex-albuminous seeds | P | Wheat, Castor |
| B | Albuminous seeds | Q | Black pepper, Beet |
| C | Perisperm | R | Pea, Groundnut |
Codes:
| A | B | C | |
| 1. | P | Q | R |
| 2. | Q | P | R |
| 3. | R | P | Q |
| 4. | R | Q | P |
Subtopic: Â Seed |
 87%
From NCERT
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Assertion(A): Geitonogamy is similar to autogamy.
Reason(R): Pollen grains come from the same flower of a different plant.
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. (A) is false, but (R) is true.
Reason(R): Pollen grains come from the same flower of a different plant.
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. (A) is false, but (R) is true.
Subtopic: Â Pollination & Outbreeding Devices |
 76%
From NCERT
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Assertion(A): Angiosperms have a unique phenomenon called double fertilization.
Reason(R): Double fertilization includes triple fusion and syngamy in the embryo sac.
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. (A) is false, but (R) is true.
Reason(R): Double fertilization includes triple fusion and syngamy in the embryo sac.
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. (A) is false, but (R) is true.
Subtopic: Â Double Fertilization |
From NCERT
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Assertion(A): Seed formation is more dependable (assured) in angiosperms.
Reason(R): Reproductive processes such as pollination and fertilization are dependent on water in 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. (A) is false, but (R) is true.
Reason(R): Reproductive processes such as pollination and fertilization are dependent on water in 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. (A) is false, but (R) is true.
Subtopic: Â Seed |
 73%
From NCERT
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Zea mays have 20 chromosomes in its somatic cell. The number of chromosomes in its endosperm will be:
1. 10
2. 20
3. 30
4. 40
1. 10
2. 20
3. 30
4. 40
Subtopic: Â Double Fertilization |Â Endosperm |
 78%
From NCERT
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The two innermost wall layers of microsporangium in an anther are:
| 1. | Endothecium and tapetum |
| 2. | Epidermis and endodermis |
| 3. | Epidermis and middle layer |
| 4. | Middle layer and tapetum |
Subtopic: Â Stamen: Microsporangium |
 82%
From NCERT
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