Q. No.Double fertilization, a characteristic feature of angiosperms, was discovered independently by Sergei Nawaschin and Léon Guignard. in France. It involves the joining of a female gametophyte with two male gametes. In double fertilization, the maternal contribution to the genetic constitution of the endosperm is:
1. same that of the embryo
2. double that of the embryo
3. triple that of embryo
4. quadruple that of embryo
1. same that of the embryo
2. double that of the embryo
3. triple that of embryo
4. quadruple that of embryo
Plant species pollinated by water fall into two categories:
| (i) | Those that distribute their pollen to the surface of water |
| (ii) | Those that distribute their pollen beneath the surface of water |
The correct examples of the two categories will be:
| (i) | (ii) | |
| 1. |
Vallisneria |
Sea grasses |
|
2. |
Water hyacinth |
Sea grasses |
|
3. |
Sea grasses |
Water lily |
|
4. |
Sea grasses |
Vallisneria |
Match each item in Column I with one in Column II and select your answer from the codes given:
|
Column I |
Column II |
||
|
A |
Stage at which more percent of angiosperms shed their pollen |
P |
3-celled |
|
B |
Pollen grains lose viability within 30 minutes of their release in |
Q |
2-celled |
|
C |
Persistent endosperm |
R |
Some cereals |
|
S |
Some members of Rosaceae |
||
|
T |
Coconut |
||
|
U |
Groundnut |
Codes:
|
A |
B |
C |
|
|
1. |
P |
S |
U |
|
2. |
P |
R |
T |
|
3. |
Q |
R |
T |
|
4. |
Q |
S |
U |
In strawberry:
I. The fruit is actually not a berry
II. Fleshy part is derived from ovaries
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
In the given diagram showing T.S. of a typical angiosperm anther, the cells of which part are most likely to undergo mitosis, that is not normal, due to which many of them become bi or multinucleate?
| 1. | 1 | 2. | 2 |
| 3. | 3 | 4. | 4 |
| 1. | ovary is the enlarged apical portion of the pistil; the ovary contains ovules, which develop into seeds upon fertilization |
| 2. | ovary is the enlarged basal portion of the pistil; the ovary contains ovules, which develop into seeds upon fertilization |
| 3. | ovary is the enlarged basal portion of the pistil; the ovary contains ovules, which develop into fruits upon fertilization |
| 4. | ovary is the enlarged apical portion of the pistil; the ovary contains ovules, which develop into fruits upon fertilization |
| I: | In castor and maize, autogamy is prevented but not geitonogamy |
| II. | In papaya, both autogamy and geitonogamy are prevented |
| 1. | Both I and II | 2. | Only I |
| 3. | Only II | 4. | Neither I nor II |
I. is a type of apomixis
II. produces embryos that are genetically identical to the parent plant
1. Both I and II are correct
2. Only I is correct
3. Only II is correct
4. Both I and II are incorrect
| 1. | 50 | 2. | 100 |
| 3. | 200 | 4. | 400 |
| I: | Each anther develops four microsporangia |
| II: | Each microspore mother cell undergoes meiosis and produces four haploid microspores |
| III: | Each microspore gives rise to a male gametophyte |
2. Only I and III are correct
3. Only II and III are correct
4. I, II and III are correct
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