Q.1. Among the terms listed below, those that of are not technically correct names for a floral whorl are:
(a) i and iv
(b) iii and iv
(c) ii and iv
(d) i and ii
Q.2. Embryo sac is to ovule as _______ is to an anther.
(c) Pollen grain
Q.3. In a typical complete, bisexual and hypogynous flower the arrangement of floral whorls on the thalamus from the outermost to the innermost is:
(a) Calyx, corolla, androecium and gynoecium
(b) Calyx, corolla, gynoecium and androecium
(c) Gynoecium, androecium, corolla and calyx
(d) Androecium, gynoecium, corolla and calyx
Arrangement of floral whorls on the thalamus from the outermost to the innermost is calyx, corolla, androecium and gynoecium.
Q.4. A dicotyledonous plant bears flowers but never produces fruits and seeds. The most probable cause for the above situation is:
(a) Plant is dioecious and bears only pistillate flowers
(b) Plant is dioecious and bears both pistillate and staminate flowers
(c) Plant is monoecious
(d) Plant is dioecious and bears only staminate flowers
A dicotyledonous plant bears flowers but never produces fruits and seeds because plant is dioecious and bears only staminate flowers.
Q.5. The outermost and innermost wall layers of microsporangium in an anther are respectively:
(a) Endothecium and tapetum
(b) Epidermis and endodermis
(c) Epidermis and middle layer
(d) Epidermis and tapetum
Wall layers of microsporangium in an anther are:
Q.6. During microsporogenesis, meiosis occurs in:
(b) Microspore mother cells
(c) Microspore tetrads
(d) Pollen grains
During microsporogenesis, meiosis occurs in microspore mother cells.
Q.7. From Among the sets of terms given below, identify those that are associated with the gynoecium.
(a) Stigma, ovule, embryo sac, placenta
(b) Thalamus, pistil, style, ovule
(c) Ovule, ovary, embryo sac, tapetum
(d) Ovule, stamen, ovary, embryo sac
Stigma, ovule, embryo sac and placenta are associated with the gynoecium.
Q.8. Starting from the innermost part, the correct sequence of parts in an ovule are,
(a) Egg, nucellus, embryo sac, integument
(b) Egg, embryo sac, nucellus, integument
(c) Embryo sac, nucellus, integument, egg
(d) Egg, integument, embryo sac, nucellus
The correct sequence of parts in an ovule are
Q.9. From the statements given below choose the option that are true for a typical female gametophyte of a flowering plant:
i. It is 8-nucleate and 7-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
(a) i and iv,
(b) ii and iii
(c) i and ii
(d) ii and iv
A typical female gametophyte of a flowering plant is 8-nucleate and 7-celled at maturity and free-nuclear during the development.
Q.10. Autogamy can occur in a chasmogamous flower if:
(a) Pollen matures before maturity of ovule
(b) Ovules mature before maturity of pollen
(c) Both pollen and ovules mature simultaneously
(d) Both anther and stigma are of equal lengths
In a normal flower which opens and exposes the anthers and stigma complete autogamy is rather rare. Autogamy in such flowers requires synchrony in pollen release and stigma receptivity and also, the anthers and the stigma should lie close to each other so that self-pollination can occur.
Q.11. Choose the correct statement from the following:
(a) Cleistogamous flowers always exhibit autogamy
(b) Chasmogamous flowers always exhibit geitonogamy
(c) Cleistogamous flowers exhibit both autogamy and geitonogamy
(d) Chasmogamous flowers never exhibit autogamy
Cleistogamous flowers are invariably autogamous as there is no chance of cross-pollen landing on the stigma. Cleistogamous flowers produce assured seed-set even in absence of pollinators.
Example of cleistogamous flowers are Viola (common pansy), Oxalis, Commelina, Arachis hypogea and Oryza sativa.
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:
Pollination by wind is called anemophily. Anemophilous flowers are small, in conspicuous non-scented without bright colours, nectar and fragrance. Wind pollination also requires that the pollen grains are light and non-sticky which is in large numbers and its stigmas are long and feathery.
Q.13. From among the situations given below, choose the one that prevents both autogamy and geitonogamy.
(a) Monoecious plant bearing unisexual flowers
(b) Dioecious plant bearing only male or female flowers
(c) Monoecious plant with bisexual flowers
(d) Dioecious plant with bisexual flowers
Q.14. In a fertilised embryo sac, the haploid, diploid and triploid structures are:
(a) Synergid, zygote and primary endosperm nucleus
(b) Synergid, antipodal and polar nuclei
(c) Antipodal, synergid and primary endosperm nucleus
(d) Synergid, polar nuclei and zygote
In a fertilised embryo sac, the haploid, diploid and triploid structures are synergid, zygote and primary endosperm nucleus, respectively.
Q.15. In an embryo sac, the cells that degenerate after fertilisation are:
(a) Synergids and primary endosperm cell
(b) Synergids and antipodals
(c) Antipodals and primary endosperm cell
(d) Egg and antipodals
In an embryo sac, synergids and antipodals degenerate after fertilisation.
Pericarp (fruit wall)
Testa (Outer Seed Coat)
Tegmen (Inner seed coat)
Q.16. While planning for an artificial hybridization programme involving dioecious plants, which of the following steps would not be relevant:
(a) Bagging of female flower
(b) Dusting of pollen on stigma
(d) Collection of pollen
Q.17. In the embryos of a typical dicot and a grass, true homologous structures are:
(a) Coleorhiza and coleoptile
(b) Coleoptile and scutellum
(c) Cotyledons and scutellum
(d) Hypocotyl and radicle
Cotyledons of the typical dicot embryo are simple structures generally thick and swollen due to storage of food reserves (as in legumes) and embryo of monocots consists of one large and shield shaped cotyledon known as scutellum situated towards one side (lateral) of the embryonal axis. E.g.: Grass family, Sorghum.
Q.18. The phenomenon observed in some plants wherein parts of the sexual apparatus is used for forming embryos without fertilisation is called:
(c) Vegetative propagation
(d) Sexual reproduction
Q.19. In a flower, if the megaspore mother cell forms megaspores without undergoing meiosis and if one of the megaspores develops into an embryo sac, its nuclei would be:
(c) A few haploid and a few diploid
(d) With varying ploidy
Solution. If a fruit is formed without fertilisation of ovary, it is called a parthenocarpic fruit,
Example: banana and grape.
Q.20. The phenomenon wherein, the ovary develops into a fruit without fertilisation is called:
(c) Asexual reproduction
(d) Sexual reproduction
If a fruit is formed without fertilisation of ovary, it is called a parthenocarpic fruit
Example: banana and grape.
VERY SHORT ANSWER TYPE QUESTIONS
Q.1. Name the component cells of the ‘egg apparatus’ in an embryo sac.
Ans. Egg apparatus have three cells—one egg cell and two synergids.
Q.2. Name the part of gynoecium that determines the compatible nature of pollen grain.
Ans. Compatible nature of pollen grain is determined by the stigma of carpel/ pistil.
Q.3. Name the common function that cotyledons and nucellus perform.
Ans. Both cotyledons and nucellus provide nourishment.
Q.4. Complete the following flow chart
Q.5. Indicate the stages where meiosis and mitosis occur (1, 2 or 3) in the flow chart.
Q.6. In the diagram given below, show the path of a pollen tube from the pollen on the stigma into the embryo sac. Name the components of egg apparatus.
Ans. Components of egg apparatus: one egg cell and two synergids.
Q.7. Name the parts of pistil which develop into fruit and seeds.
Ans. Ovary of pistil develops into fruit while ovules develop into seeds.
Q.8. In case of polyembryony, if an embryo develops from the synergid and another from the nucellus which is haploid and which is diploid?
Ans. Synergid embryo is haploid and nucellar embryo is diploid.
Q.9. Can an unfertilised, apomictic embryo sac give rise to a diploid embryo? If yes, then how?
Ans. Yes, if the embryo develops from the cells of nucellus or integument it will be diploid.
Q.10. Which are the three cells found in a pollen grain when it is shed at the three celled stage?
Ans. One vegetative cell and two male gametes
Q.11. What is self-incompatibility?
Ans. The device to prevent inbreeding is self-incompatibility or self-sterility. This is a genetic mechanism and prevents self-pollen (from the same flower or other flowers of the same plant) from fertilising the ovules by inhibiting pollen germination or pollen tube growth in the pistil.
Q.12. Name the type of pollination in self-incompatible plants.
Q.13. Draw the diagram of a mature embryo sac and show its 8-nucleate, 7-celled nature. Show the following parts: antipodals, synergids, egg, central cell, polar nuclei.
Fig: The mature embryo sac
Q.14. Which is the triploid tissue in a fertilised ovule? How is the triploid condition achieved?
Ans. The triploid tissue in the ovule is the endosperm. Its triploid condition is attained due to the fusion of two polar nuclei and one nucleus of male gamete (also referred to as triple fusion).
Q.15. Are pollination and fertilisation necessary in apomixis? Give reasons.
Ans. No, they are not necessary. Apomixis is actually an alternative to sexual
reproduction although the female sexual apparatus is used in the process. In apomicts, embryos can develop directly from the nucellus or synergid or egg. Therefore, there is no need for either pollination or fertilisation.
Q.16. Identify the type of carpel with the help of diagrams given below:
(a) Multicarpellary, Syncarpous pistil or Papaver
(b) Multicarpellary, apocarpous gynoecium of Michelia
Q.17. How is pollination carried out in water plants?
Ans. Pollination by water is called hydrophily. Some examples of water pollinated plants are Vallisneria and Hydrilla (both are angiospermic hydrophytes) which grow in fresh water and several marine sea-grasses such as Zostera. Not all aquatic plants use water for pollination. In a majority of aquatic plants such as water hyacinth and water lily, the flowers emerge above the level of water and pollinated by insects or wind as in most of the land plants.
Q.18. What is the function of the two male gametes produced by each pollen grain in angiosperms.
Ans. After entering one of the synergids, the pollen tube releases the two male gametes into the cytoplasm of the synergid. One of the male gametes moves towards the egg cell or oosphere and fuses with its nucleus, thus completing the syngamy. This results in the formation of a diploid cell, the zygote. The other male gamete moves towards the two polar nuclei located in the central cell and fuses with them to produce a triploid primary endosperm nucleus (PEN).