In angiosperms, triple fusion results in the formation of:
1. | Zygote | 2. | Endosperm |
3. | Nucellus | 4. | PEC |
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Identify the incorrect statement regarding Parthenium hysterophorus:
1. | Its pollens are a very common cause of severe respiratory allergies. |
2. | It was introduced in India accidentally as a contaminant in wheat. |
3. | It is a native of tropical America |
4. | It is non-invasive and limited to certain pockets in India only |
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Match the structure in Column I with the description in Column II and choose your answer from the codes given below:
Column I | Column II | ||
A. | Stigma | a. | Landing platform for pollen grains |
B. | Ovary | b. | Basal bulged part of the pistil |
C. | Placenta | c. | Part of the ovary where funiculus attaches |
D. | Ovule | d. | Megasporangium |
Codes
A | B | C | D | |
1. | a | b | c | d |
2. | a | c | b | d |
3. | b | a | d | c |
4. | d | c | b | a |
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The only type of pollination which during pollination brings a genetically different type of pollen grains to the stigma is:
1. | Chasmogamy | 2. | Cleistogamy |
3. | Geitonogamy | 4. | Xenogamy |
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Identify the incorrect statement regarding water-pollinated flowers:
1. | Pollination by water is rare and is seen in monocotyledons mostly |
2. | Pollen grains in most are covered by a mucilaginous covering |
3. | Produce nectar |
4. | Are not very colourful |
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Whether a pollen grain will be able to germinate on a stigma is primarily decided by:
1. | The stage at which the pollen is shed |
2. | Recognition by the stigma |
3. | Maturity of the egg cell in the embryosac |
4. | Environmental conditions |
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Syngamy in angiosperms results in the formation of:
1. | A haploid cell | 2. | A diploid cell |
3. | A triploid cell | 4. | A polyploid cell |
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The outer hard layer of the pollen wall is made up of:
1. | Callose, which is easily digested by enzymes |
2. | Sporopollenin, which is resistant to all enzymes |
3. | Hemicellulose, which is difficult to digest by enzymes |
4. | Calcium pectate, which is easily digested by enzymes |
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In over 60 % of angiosperms, pollen grains are shed at:
1. | 2-celled stage | 2. | 3-celled stage |
3. | 4-celled stage | 4. | 1-celled stage |
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Transfer of pollens from the anther to the stigma of the same flower is called:
1. | Autogamy | 2. | Geitonogamy |
3. | Xenogamy | 4. | Cleistogamy |
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