Multiple Choice Questions

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Assertion : Sphagnum is slowly carbonised, compressed and fossilised over thousands of years to produce a dark spongy mass called peat.

Reason : Peat helps to keep soil porous and it also improves water holding capacity of the soil.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


B.

If both assertion and reason are true but reason is not the correct explanation of assertion

Sphagnum is commonly known as peat moss. Its accumulations can store water, since both living and dead plants can hold large qauntities of water inside their cells. Sphagnum and peat formed does not decay readily because of the phenolic compounds embedded in the moss's cell walls.


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Which of the following is not an invasive species?

  • Parthenium hysterophorus

  • Nelumbo (lotus)

  • Lantana camara

  • Eichhornia crassipes


Assertion: In basidiomycetes, basidiospores are produced endogenously in the basidium.

Reason: In ascomycetes, ascospores are produced exogenously in ascus.

  • If both assertion and reason are true and reason is the correct explanation of assertion.

  • If both assertion and reason are true but reason is not the correct explanation of assertion.

  • If assertion is true but reason is false.

  • If both assertion and reason are false.


Which of the following groups of algae produces algin?

  • Phaeophyceae and Chlorophyceae

  • Rhodophyceae and Phaeophyceae

  • Chlorophyceae and Rhodophyceae

  • Phaeophyceae only


Assertion: The leaves in gymosperms are well adapted to with stand extremes of temperature, humidity and wind.

Reason: Unlike bryophytes and pteridophytes, in gymnosperms the male and female gametophytes do not have an independent free-living existence.

  • If both assertion and reason are true and reason is the correct explanation of assertion.

  • If both assertion and reason are true but reason is not the correct explanation of assertion.

  • If assertion is true but reason is false.

  • If both assertion and reason are false.


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Which of the given genera is homosporous

  • Cycas

  • Pinus

  • Selaginella

  • Lycopodium


In which of the following sets of organisms, does the external fertilization occur?

  • Echinodermata and mosses

  • Hemichordata and ferns

  • Amphibians and algae

  • Reptiles and gymnosperms


Occurrence of triploid (3n) primary endosperm nucleus is a characteristic feature of

  • Algae

  • Gymnosperms

  • Angiosperms

  • Bryophytes


Assertion: Presence of large amounts of nutrients in water body causes excessive growth of planktonic algae.

Reason: It is due to biomagnification.

  • If both assertion and reason are true and reason is the correct explanation of assertion. 

  • If both assertion and reason are true but reason is not the correct explanation of assertion. 

  • If assertion is true but reason is false. 

  • If both assertion and reason are false.


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Gametophyte and sporophyte are independent of each other in which of the following groups?

  • Pteridophytes

  • Angiosperms

  • Gymnosperms

  • Bryophytes


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