During microsporogenesis, meiosis occurs in
1. endothecium
2. microspore mother cells
3. microspore tetrads
4. pollen grains
From among the sets of terms given below, identify those that are associated with the gynoecium :
1. Stigma, ovule, embryo sac, placenta
2. Thalamus, pistil, style, ovule
3. Ovule, ovary, embryo sac, tapetum
4. Ovule, stamen, ovary, embryo sac
Starting from the innermost part, the correct sequence of parts in an ovule is
1. egg, nucellus, embryosac, integument
2. egg, embryosac, nucellus, integument
3. embryosac, nucellus, integument, egg
4. egg, integument, embryo sac, nucellus
From the statements given below choose the option that is true for a typical female gametophyte.
i. | It is eight-nucleate and seven-celled at maturity. |
ii. | It is free-nuclear during the development. |
iii. | It is situated inside the integument, but outside the nucellus. |
iv. | It has an egg apparatus situated at the chalazal end. |
1. (i) and (iv)
2. (ii) and (iii)
3. (i) and (ii)
4. (ii) and (iv)
Autogamy can occur in a chasmogamous flower if
1. pollen matures before maturity of ovule
2. ovules mature before maturity of pollen
3. both pollen and ovules mature simultaneously
4. both anther and stigma are of equal lengths
1. | Cleistogamous flowers always exhibit autogamy |
2. | Chasmogamous flowers always exhibit geitonogamy |
3. | Cleistogamous flowers exhibit both autogamy geitonogamy |
4. | Chasmogamous flowers never exhibit autogamy |
Q. 12 A particular species of plant produces light, non-sticky pollen in large numbers and its stigmas are long and feathery. These modifications facilitate pollination by
1. insects
2. water
3. wind
4. animals
From among the situations given below, choose the one that prevents both autogamy and geitonogamy.
1. Monoecious plant bearing unisexual flowers.
2. Dioecious plant bearing only male or female flowers.
3. Monoeciousplant with bisexual flowers.
4. Dioecious plant with bisexual flowers.
In a fertilised embryo sac, the haploid, diploid, and triploid structure are
(1) synergid, zygote and primary endosperm nucleus
(2) synergid, antipodal and polar nuclei
(3) antipodal, synergid and primary endosperm nucleus
(4) synergid, polar nuclei and zygote
In an embryo sac, the cells that degenerate after fertilisation are
1. synergids and primary endosperm cell
2. synergids and antipodals
3. antipodals and primary endosperm cell
4. egg and antipodals