Q.1. Persistent nucellus in the seed is known as (2019)
In some seeds, remains of nucellus persist.
This residual nucellus which persists in the seed is called perisperm
Examples: black pepper, coffee, castor, cardamum, Nymphaea.
Q.2. What is the fate of the male gametes discharged in the synergid ? (2019)
(a) One fuses with the egg and other fuses with central cell nuclei.
(b) One fuses with the egg, other(s) degenerates in the synergid.
(c) All fuse with the egg.
(d) One fuses with the egg, other(s) fuse(s) with synergid nucleus.
During double fertilisation in angiosperms, one male gamete fuses with the egg to form the diploid zygote (syngamy or generative fertilisation). The diploid zygote finally develops into embryo. The other male gamete fuses with the two polar nuclei (or secondary nucleus) to form the triploid primary endosperm nucleus, PEN (triple fusion or vegetative fertilisation).
Q.3. Which one of the following statement regarding post-fertilisation dcvelopment in flowering plants is incorrect? (2019)
(a) Ovules develop into embryo sac
(b) Ovary develops into fruit.
(c) Zygote develops into embryo.
(d) Central cell develops into endosperm.
Q.4. Which is the most common type of embryo sac in angiosperms? (2019)
(a) Tetrasporic with one mitotic stage of divisions
(b) Monosporic with three sequential mitotic divisions
(c) Monosporic with two sequential mitotic divisions
(d) Bisporic with two sequential mitotic divisions
Q.5. What type of pollination takes place in Vallisneria ? (2019)
(a) Pollination occurs in submerged condition by water.
(b) Flowers emerge above surface of water and pollination occurs by insects.
(c) Flowers emerge above water surface , pollen is carried by wind.
(d) Male flowers are carried by water currents to female flowers at surface of water.
Q.6. which one of the following, both autogamy mid geitonognmy are provenled? (2019)
Q.7. Which of the following has proved helpful in preserving pollen as fossils? (2018)
(b) Cellulosic intine
(c) Oil content
Exine of pollen grain is made up of highly resistant fatty substance called sporopollenin, which is not degraded by any enzyme. It is not affected by high temperature, strong acid or strong alkali. Because of the sporopollenin, pollen grains are well preserved as microfossils.
Q.8. Winged pollen grains are present in (2018)
Each pollen grain of Pinus has two wing like structures which enable it to float in air, as an adaptation for dispersal by wind. Pollen grains of mustard, Cycas and mango are not winged.
Q.9. Double fertilisation is (2018)
(a) Fusion of two male gametes of a pollen tube with two different eggs
(b) Fusion of one male gamete with two polar nuclei
(c) Fusion of two male gametes with one egg
(d) Syngamy and triple fusion.
Double fertilisation is unique and universal feature of angiosperms. Total number of nuclei involved in double fertilisation is five, i.e., 2 in syngamy and 3 in triple fusion. Syngamy is fusion of one male gamete with egg to form zygote. Triple fusion occurs when the second male gamete with 2 polar nuclei or secondary nucleus to form triploid primary endosperm nucleus.
Q.10. Functional megaspore in an angiosperm develops into an (2017)
(b) Embryo sac
In angiosperms, the functional megaspore is the first cell of female gametophyte. It enlarges and Undergoes three nuclear mitotic divisions to form embryo sac.
Q.11. Attractants and rewards are required for (2017)
Entomophily is the most common type 0f zoophily where pollination takes place through the agency of insects. Entomophilous flowers are brightly coloured and secrete nectar to attract visiting insects.
Anemophily (wind pollination) and hydrophil (water pollination) do not require attractants c rewards due to the involvement of abiotic pollination its. Cleistogamy is self pollination in, close flowers.
Q.12. Flowers which have single ovule in the ovary and are packed into inflorescence are usually pollinated by (2017)
Single ovule in the ovary and flowers racked into inflorescence are characteristics of wind pollinated flowers.
Q.13. A dioecious flowering plant prevents both (2017)
(a) Autogamy and geitonogamy
(b) Geitonogamy and xenogamy
(c) Cleistogamy and xenogamy
(d) Autogamy and xenogamy.
Dioecious plants are those plants in which male flowers and female flowers are borne on different plants. Therefore, they prevent both autogamy and geitonogamy.
Q.14. Double fertilisation is exhibited by (2017)
Q.15. In majority of angiosperms (2016)
(a) Egg has a filiform apparatus
(b) There are numerous antipodal cells
(c) Reduction division occurs in the megaspore mother cells
(d) A small central cell is present in that embryo sac
Q.16. Pollination in water hyacinth and water lily is brought about by the agency of (2016)
(b) Insects or wind
In aquatic plants with emergent flowers.
Example: water lily, water hyacinth pollination takes place by wind or insects.
Q.17. The ovule of an angiosperm is technically equivalent to (2016)
(c) Megasporem other cell
The ovule of an angiosperm is equivalent to integumented megasporangium.
Q.18. The coconut water from tender coconut represents (2016)
(a) Free nuclear proembryo
(b) Free nuclear endosperm
(d) Fleshy mesocarp
Coconut has multicellular endosperm (called coconut meal) in the outer part and free nuclear as well as vacuoles endonorm (called coconut water) in the centre.
Q.19. Which one of the following statements is not true? (2016)
(a) Pollen grains of many species cause severe allergies.
(b) Stored pollen in liquid nitrogen can be used in the crop breeding programmes.
(c) Tapetum helps in the dehiscence of anther.
(d) Exine of pollen grains is made up of sporopollenin.
Tapetum is the innermost wall layer of microsporangium that nourishes developing pollen grains.
Q.20. Seed formation without fertilisation in flowering plants involves the process of (2016)
(a) Somatic hybridisation
Apomixis is a reproductive process which does not involve gametic fusion. In apomictic flowering plants there is no fertilisation and embryos develop simply by division of a cell of ovule.
Q.21. Which of the following statements is not correct? (2016)
(a) Pollen germination and pollen tube growth are regulated by chemical components of pollen interacting with those of the pistil.
(b) Some reptiles have also been reported as pollinators in some plant species.
(c) Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into the style.
(d) Insects that consume pollen or nectar without bringing about pollination are called pollen/ nectar robbers.
Pollen-pistil interaction is the group of events that occur from the time of pollen deposition over die stigma to the time of pollen tube entry 0vule. It is a safety measure to ensure that illegitimate Crossing does not occur. Pollen grains of number of may settle over a stigma. The pollens belonging same species would germinate while other fail to do so, but the pollen tube of the compatible pollen will grow through the style to reach the ovule whereas growth of incompatible pollens will be arrested at stigmatic disc or sometimes in the beginning part of style.
Q.22. Proximal end of the filament of stamen is attached to the (2016)
(b) Thalamus or petal