Tag: classification of pteridophytes
Questions Related to classification of pteridophytes
Pick up the wrongly matched pair.
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Equisetum - horsetail
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Psilotum - whisk fern
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Selaginella - peat moss
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Dryopteris - male shield fern
Selaginella is spike moss or club moss. Peat moss is Sphagnum (Bryophyte).
In pteridophytes, the spores are formed in specialised leaves known as
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Sporophylls
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Spikes
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Inflorescece
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Cones
Pteridophytes are vascular plants. Leaves called sporophylls produce clusters of capsular structures called sporangia that bears spores which germinate and yield gametophytes. Hence they show alternation of generations, in which a sporophyte produces spores through meiosis and a gametophyte forms gametes by mitosis.
Horse tails are
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Lycopsida
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Pteropsida
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Psilopsida
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Sphenopsida
The correct answer is 'Sphenopsida'
One of the following is incorrect set of analogy amongst Selaginella and gymnosperms
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Megasporangium- nucellus of ovule
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Female prothallus- endosperm
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Ligule- carpellary scale
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Megasporophyll- female gametophyte
Option D is mismatched as the sporangia in selaginella contain four very large yellow spores. These four are the result of meiosis from a single sporocyte. The spores are called megaspores because of their large size. This makes the sporangium a megasporangium and the sporophyll a megasporophyll.
Azolla is used in the cultivation of
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Maize
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Sorghum
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Wheat
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Rice
Azolla is extensively grown in rice paddies to increase rice production by more than to 50%. Nitrogen is the single most limiting factor in rice cultivation, strongly affecting the crop yield. Azolla substantially increases the amount of nitrogen fertiliser available to growing rice and it is has been used for thousands of years as a green nitrogen fertiliser to increase rice production.
Club mosses are
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Lycopsida
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Pteropsida
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Psilopsida
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Sphenopsida
The correct answer is 'lycopsida'
Which of the followings is fern?
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Psilopsida
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Pteropsida
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Lycopsida
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Sphenopsida
Rhizophore in Selaginella is
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A modified leaf
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A root
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A shoot
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Organ Sui generis
Rhizophores is a structure of controversial morphological nature.They are leafless and positively geotropic organs that have localised origin and develop from angle meristems. Goebel and Bower considered them as Organs sui generis (i.e.,neither roots or shoots). According to J.C.Shoute,Organ sui generis is one that is a novelty and has not arisen as result of metamorphosis of any organ.
Heteromorphic alternation of generations is found in
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Spirogyra
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Mucor
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Selaginella
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Pinus
Heteromorphic alternation of generation means a sporophytic phase and gametophytic phase alternate each other. Eg: Dryopteris
In Dryopteris, the sori are borne
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Laterally
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Abaxially
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Adaxially
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Marginally
In Dryopteris sori, a group of sporangia covered with indusium are present along the margin of pinnae or leaflets. In it 2-8 sori are borne on the abaxial surface of the mature fronds (sporophylls). They are situated in two rows at the tips of the veinlets in between the midrib and the margins. The sori appear reniform due to the kidney shaped protective thin and membranous covering, called as indusium.