Classification of Plants
Short Questions and Answers
One Mark Questions with Answers
1. On germination, moss spores produce
Answer: (d) protonema
2.Which of the following includes a diploid structure?
(a) gametophyte and spore mass
(b) gametophyte, archegonia and oospheres
(c) gametophyte and capsule
(d) gametophyte, antheridia and sperm
Answer: (c) gametophyte and capsule
3. Apophysis of moss is
(a) lower part of capsule
(b) terminal part of capsule
(c) part of peristome
(d) sterile filaments in male receptacle
Answer: (a) lower part of capsule
4. Peristome of moss takes part in
(c) spore dispersal
(d) absorption of water and minerals
Answer: (c) spore dispersal
5. Kidney shaped covering of sorus in Dryopteris is
Answer: (a) indusium
6. Neck canal cells present in archegonium of Dryopteris are
(a) one with one nucleus
(b) one with two nuclei
Answer: (b) one with two nuclei
7. Botanical snakes are
Answer: (c) pteridophytes
8. Plants having vascular tissues but lacking seeds are
Answer: (c) pteridophytes
9. In fern, the venation is
(a) open furcate
Answer: (b) reticulate
10. Antherozoids of Dryopteris are
(a) biflagellate and sickle shaped
(b) multiflagellate and sickle shaped
(c) biflagellate and coiled shaped
(d) multiflagellate and coiled shaped
Answer: (d) multiflagellate and coiled shaped
11. Pteridophytes differ from mosses in having
(a) independent gametophyte
(b) dependent sporophyte
(c) independent and dominant sporophyte
(d) flagellate antherozoids
Answer: (c) independent and dominant sporophyte
12. Young leaves of Fern are protected by
Answer: (a) ramenta
13. Sporangia bearing fern leaf is called
Answer: (d) sporophyll
14. Gymnosperms differ from angiosperms in having
(b) vascular tissues
(c) naked ovules
Answer: (c) naked ovules
Two Marks Questions with Answers
1. Differentiate between cryptogamae and phanerogamae
Answer: Cryptogams are seedless plants while phanerogams are seeded plants. Cryptogams lack ovule while phanerogams bears an ovule. Pollination or transfer of male spore to vicinity of female gamete is absent in cryptogams while pollination is present in phanerogams. Cryptogams require external water for fertilization while phanerogams do not require external water as fertilization occurs through pollen tube.
2. What are cycads?
Answer: Cycads are smaller groups of gymnosperms which have palm like habit and fern like foliage. Leaf bases are often persistent. Plants are dioeceous, i.e., microsporophylls and megasporophylls develop on separate plants. The sporophylls are aggregated to produce strobili or cones. Megasporophylls are often leaf-like and often possess ramenta. Sperms are motile. The plants are mostly xerophytic and occur in warm climate.
3. Why are the bryophytes called terrestrial amphibians?
Answer: Bryophytes are called terrestrial amphibians as they require an external layer of water on the soil surface for their existence. The external water is required for dehiscence of antheridia and archegonia, swimming of male gametes to archegonia, protection from transpiration and hence desiccation as the plant body is not covered by cuticle, supply of water to all parts through capillary in the absence of vascular tissues.
4. Mention three resemblances between algae and fungi.
Answer: (a) both occur in aquatic and semi aquatic habitats
(b) they have a simple body called thallus
(c) a differentiation of stem, leaves and roots is absent.
5. Differentiate between fungi and algae
Answer: Fungi always live in contact with organic matter while algae lives freely. Fungi live in aquatic, sub aquatic and terrestrial habitats while algae do not occur in terrestrial habitats. They are aquatic or sub aquatic. Fungi lack chlorophyll while algae possess chlorophyll. Fungi are heterotrophic in nutrition while algae are autotrophic. They absorb organic nutrients from their environment while algae absorb inorganic nutrients from their environment. The filaments are usually branched in fungi whereas in algae the filaments may be branched or unbranched.
Three Marks Questions with Answers
1. Mention three characteristic features of algae.
Answer: (a) Algae are usually aquatic, either marine or fresh water. Only a few algae occur in moist terrestrial habitats like tree trunks, wet rocks, moist soil etc.
(b) Plant body is unicellular, colonial, filamentous, parenchymatous or pseudoparenchymatous.
(c) Algae, like other aquatic plants, are covered over by mucilage. Mucilage protects the algae from epiphytic growth and decaying effect of water. It also prevents dessication if the algae happen to get exposed as many littoral species during low tide.
2. Differentiate between microsporophyll and megasporophyll.
Answer: Microsporophylls bear microsporangia while megasporophylls bear megasporangia. A microsporangium contains numerous microspores or pollen grains while a megasporangium usually bears one functional megaspore. Microspores are not retained. They are always shed while in seed plants, the megaspore is retained inside the megasporangium. The male gametophyte is formed near the female gametophyte while in seed plants, female gametophyte is produced inside the megasporangium. In angiosperms the microsporophylls is modified into stamen whereas the megasporophylls in angiosperms is rolled to produce a carpel.
3. Mention some of the characteristic features of pteridophytes.
Answer: (a) The plant body is a sporophyte.
(b) The plant body is differentiated into true stem, leaves and roots.
(c) Vascular tissues are present. They are of two types; xylem and phloem.
(d) Meiospores are formed inside sporangia.
(e) Gametophyte is small or inconspicuous.
(f) Sex organs are multicellular and jacketed.
(g) Sperms are flagellate.
4. Differentiate between antheridia and archegonia.
Answer: Antheridia are male organs of bryophytes and pteridophytes while archegonia are female organs of bryophytes, pteridophytes and gymnosperms. Antheridia are generally rounded in outline while archegonia are flask-shaped in outline. Sterile cells are absent in antheridia while sterile cells are present in archegonia. An antheridium forms a large number of male gametes while an archegonium encloses a single female gamete. The male gametes produced in an antheridium are usually motile while the female gamete or egg present in an archegonium is usually non-motile.
5. List some of the economic importance of Algae.
Answer: (a) a number of brown algae are used as food in some countries, example, Laminaria, Macrocystis. The edible brown algae are also used as fodder.
(b) Fucus and Laminaria are rich source of iodine. Potash is abundant in Macrocystis and Nereocystis.
(c) Sodium lamarin sulphate is blood anticoagulant. Laminaria and Ascophyllum have antibiotic properties.
(d) Alginic acid which is a phycocolloid is obtained commercially from a number of brown algae including the giant ones. Alginic acid and its salts are also used in obtaining emulsions sizing textiles, flameproof plastic, security glass, formation of pills and surgical threads.