In a type of apomixis known as adventive embryony, embryos develop directly from:
1. Nucellus or integument
2. Zygote
3. Synergids of antipodals of embryo sac
4. Accessory embryo sac in the ovule
Parthenocarpic fruits are produced by:
1. | Treating plants with phenyl Mercuric acetate. |
2. | Treating plants with low concentrations of gibberellic acid and auxin. |
3. | Removing androecium of flowers before releasing pollen grains. |
4. | Raising plants from vernalised seeds. |
An organic substance that can withstand environmental extremes and cannot be degraded by any enzyme is:
1. | Cuticle | 2. | Sporopollenin |
3. | Lignin | 4. | Cellulose |
Perisperm differs from endosperm in:
1. | having no reserved food. |
2. | being a diploid tissue. |
3. | its formation by fusion of a secondary nucleus with several sperms. |
4. | being a haploid tissue. |
Which one of the following statements is not true?
1. | Pollen grains of some plants cause severe allergies and bronchial afflictions in some people. |
2. | The flowers pollinated by flies and bats secrete foul odour to attract them. |
3. | Honey is made by bees by digesting pollen collected from flowers. |
4. | Pollen grains are rich in nutrients, and they are used in the form of tablets and syrups. |
Flowers that have a single ovule in the ovary and are packed into inflorescence are usually pollinated by:
1. | Water | 2. | Bee |
3. | Wind | 4. | Bat |
Tapetum :
I. | Is a layer of nutritive cells that are found within the microsporangium. |
II. | The cells are usually bigger and normally have more than one nucleus per cell because mitosis is not normal in them. |
III. | Helps in pollen wall formation, transportation of nutrients to the inner side of the anther, synthesis of callose enzyme for separation of microspore tetrads. |
Of the above statements, the correct ones are:
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
How many cells of the female gametophyte are surrounded by a cell wall and are organized into cells?
1. | 6 | 2. | 7 |
3. | 8 | 4. | 2 |
Cleistogamous flowers are:
1. | Mostly autogamous | 2. | Invariably autogamous |
3. | Mostly xenogamous | 4. | Invariably xenogamous |
Majority of the flowering plants produce:
1. | Female flowers | 2. | Male flowers |
3. | Hermaphroditic flowers | 4. | Neutral flowers |