(1) formation of seeds by fusion of gametes
(2) formation of seed without syngamy and meiosis
(3) formation of seeds with syngamy but no meiosis
(4) none of the above
Even after killing the generative cell with a laser beam, the pollen grain of a flowering plant germinates and produces normal pollen tube because
(1) laser beam stimulates pollen germination and pollen tube growth
(2) the laser beam does not damage the region from which pollen tube emerges
(3) the contents of killed generative cell permits germination and pollen tube growth
(4) the vegetative cell has not been damaged.
What is the charasteristic of tapetum ?
(1) It does not store food.
(2) It is multi-nucleated.
(3) It is multi-layered structure.
(4) It nourishes the megaspore.
Cleistogamy is leadingover anthesis because
(1) pollination agent is not required
(2) it assures heterozygosity
(3) it favours insect pollination
(4) it allows xenogamy
Sporopollenin is a constituent of pollen exine.
It can be degraded by the action of
(2) high temperature
(3) strong acids
(4) cannot be degraded
The pollen grains of rice and wheat lose their viability in ___ minutes of their release.
After double fertilizaton, a mature ovule has
(1) 1 diploid and 1 haploid cell
(2) 1 diploid and 1 triploid cell
(3) 2 haploid and 1 triploid cell
(4) 1 haploid and 1 triploid cell
How many haploid nuclei are present in a mature pollen grain?
What is the correct sequence of the formation of female gametophyte in angiosperms?
(1) Nucellus, megapore tetrad, megaspore mother cell, megaspore, female gametophyte
(2) Megaspore tetrad, nucellus, megaspore mother cell, megaspore, female gametophyte
(3) Nucellus, megaspore mother cell, megaspore tetrad, megaspore, female gametophyte
(4) Megaspore mother cell, megaspore tetrad, megaspore, nucellus, female gametophyte
Primary endosperm nucleus (PEN) is formed by the fusion of
(1) 2 polar nuclei + 1 synergid cell nucleus
(2) 1 polar nucleus + 1 antipodal cell nucleus + 1 synergid cell nucleuus
(3) 2 polar nuclei + 1 male gamete nucleus
(4) 2 antipodal cell nuclei + 1 male gamete nucleus