Phylogenetic classification systems based on—
The natural system of classification for flowering plants was given by
Which one of the following is wrongly matched?
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Solution
Cyanobacteria, e.g., Nostoc, grow in such abundance as to form water blooms. Sargassum belongs to brown algae which possess chl a, c, carotenoids, xanthophyll and a characteristic brown pigment, fucoxanthin. Commonlyknown forms of basidiomycetes are mushrooms, bracket fungi or puffballs. In Spirogyra gametes are non-flagel-lated (non-motile)but similar in size. They show amoe-boid movements.
What is common in all the three, Funaria, Dryopteris and Ginkgo?
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Solution
The female sex organ archegonium is formed in bryo-phytes (Funaria), pteridophytes (Dryopteris) and gym-nosperms (Ginkgo).
The plant body is thalloid in
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Solution
The plant body of a liverwort is haploid (n), gametophytic,small, dorsoventrally flattened, thallose, dichotomously branched fixed by unicellular and unbranched rhizoids,e.g., Marchantia.
Which of the following is not correctly matched for theorganism and its cell wall degrading enzyme?
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Solution
Algae is a plant and so its cell wall is made up of cellu-lose. Cellulase enzyme is needed for degradation of its cell wall.
Read the following statements (A-E) and answer the question which follows them.
1.In liverworts, mosses and ferns gametophytes are free-living.
2.Gymnosperms and some ferns are heterosporous.
3.Sexual reproduction in Fucus, Volvox and Albugo is oogamous.
4.The sporophyte in liveworts is more elaborate than thatin mosses.
5.Both, Pinus and Marchantia are dioecious.
How many of the above statements are correct?
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Solution
In liverworts and ferns gametophytes are free living while in fern sporophytes are free living. Gymnosperms and genera like Selaginella and Salvinia are heterosporous.The sporophyte in mosses are more elaborate than that of liverworts, Pinus is monoecious and heterosporous.Marchantia is dioecious.
Isogamous condition with non-flagellated gametes is found in :
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Solution
In Spirogyra, sexual reproduction occurs through conju-gation. Gametes are non-flagellated morphologically simi-lar.But physiologically different (isogamy with physi-ological anisogamy). Volvox and fucus are examples of oogamous and Chlamydomonas contains isogamousflag-ellated gametes .
Besides paddy fields cyanobacteria are also found inside vegetative part of :
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Solution
In Cycas specialised root called coralloid roots are asso-ciated with N2– fixing cyanobacteria either Nostoc or Anabaena. Coralloid roots lie near the soil surface. They are irregular and often dichotomously branched. Root hair and root cap are absent in these roots.
Some hyperthermophilic organisms that grow in highly acidic(pH-2)habitats belong to the two groups:
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Solution
Hyperthermophilic organisms that grow in highly acidic habitats belong to eubacteria and archae groups.