Q. No.In which one of the following, both autogamy and geitonogamy are prevented?
1. Wheat
2. Papaya
3. Castor
4. Maize
What type of pollination takes place in Vallisneria?
| 1. | Pollination occurs in submerged conditions by water. |
| 2. | Flowers emerge above the surface of water and pollination occurs by insects. |
| 3. | Flowers emerge above the water surface and pollen is carried by the wind. |
| 4. | Male flowers are carried by water currents to female flowers at the surface of the water. |
Which is the most common type of embryo sac in angiosperms?
1. Tetrasporic with one mitotic stage of division
2. Monosporic with three sequential mitotic divisions
3. Monosporic with two sequential mitotic divisions
4. Bisporic with two sequential mitotic divisions
| A: | Pollen grains carry the male gamete from microsporangium to micropyle of ovule in angiosperms. |
| B: | Pollen grain itself a male gamete further divides and form another one on stigma only. |
1. Both A and B are correct
2. A is correct only
3. B is correct only
4. Both A and B are incorrect
Read the following statements carefully and select the correct
a. Tapetum cells possess dense cytoplasm and generally have more than one nucleus
b. Sporopollenin is absent in the areas called germ pore
c. Generative cell is small, spindle shaped with a irregularly shaped nuclei
d. Spindle of first mitosis in pollen is asymmetric
1. a,b,c & d
2. a,b & c
3. a,c & d
4. a,b & d
The cell in the pollen grain which is responsible for giving rise to male gamete is
1. Rod shaped with dense cytoplasm
2. Of smaller size and float in the cytoplasm
3. Capable of dividing meiotically and give rise two male gamete
4. It has abundant food reserve and large irregularly shaped nucleus.
Which of the following statements is false?
| I: | Vallisneria and Hydrilla are fresh water plants while sea-grasses (e.g. Zostera) are marine plant. |
| II: | Pollination in water lily / Lotus (Nymphea) and Eichhornia (water hyacinth) takes place by insects. |
| III: | In majority of aquatic plants flowers emerge above the level of water and are pollinated by insects or wind. |
| IV: | In most of the water pollinated species, pollen grains are protected from wetting due to presence of mucilaginous covering. |
| V: | In hydrophilous plants pollen grains are spherical. |
| 1. | All | 2. | None |
| 3. | V | 4. | IV |
Which of the following is false about xenogamy?
1. It is the transfer of pollen grains from anther to stigma of another plant of the same species.
2. It produces genetic variation
3. It is genetically and ecologically (= functionally) cross pollination.
4. It occurs in cleistogamous flowers
Choose the correct statement from the following:
| 1. | Cleistogamous flowers always exhibit autogamy |
| 2. | Chasmogamous flowers always exhibit geitonogamy |
| 3. | Cleistogamous flowers exhibit both autogamy and geitonogamy |
| 4. | Chasmogamous flowers never exhibit autogamy |
Mark the incorrect statement
| 1. | Outer three layers of anther wall are protective in function |
| 2. | Sporogenous tissue occupies the centre of each microsporangium |
| 3. | Cells of tapetum and endothecium show increase in DNA contents by endomitosis and polyteny |
| 4. | Ploidy level of microspore tetrad is haploid |
© 2024 GoodEd Technologies Pvt. Ltd.