What does the filiform apparatus do at the entrance into ovule?
1. It helps in the entry of pollen tube into a synergid
2. It prevents entry of more than one pollen tube into the embryo sac
3. It brings about opening of the pollen tube
4. It guides pollen tube from a synergid to egg
Which one of the following is resistant to enzyme action?
(1) Cork
(2) Wood fibre
(3) Pollen exine
(4) Leaf cuticle
Male gametes in angiosperms are formed by the division of:
(1) microspore
(2) generative cell
(3) vegetative cell
(4) microspore mother cell
Parthenocarpic tomato fruits can be produced by :
(1) removing androecium of flowers before pollen grains are released
(2) treating the plants with low concentrations of gibberellic acid and auxins
(3) raising the plants from vernalized seeds
(4) treating the plants with phenylmercuric acetate.
Long filamentous threads protruding at the end of a young cob of maize are :
1. | anthers | 2. | styles |
3. | ovaries | 4. | hairs |
In angiosperms, microsporogenesis and megasporogenesis
(1) occur in anther
(2) form gametes without further divisions
(3) involve meiosis
(4) occur in ovule
Coconut water from a tender coconut is
1. Immature embryo
2. Free nuclear endosperm
3. Innermost layers of the seed coat
4. degenerated nucellus
Which of of the following fruits is parthenocarpic?
1. Brinjal
2. Apple
3. Jackfruit
4. Banana
Male gametophyte in angiosperms produces
1. two sperms and a vegetative cell
2. single sperm and a vegetative cell
3. single sperm and two vegetative cells
4. three sperms
Which one of the following statements is not true?
1. Pollen grains are rich in nutrients and they are used in the form of tablets and syrups
2. Pollen grains of some plants cause severe allergies and bronchial afflictions in some
people
3. The flowers pollinated by flies and beetles secrete foul odour to attract them
4. Honey is made by bees by digesting pollen collected from flowers