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Some hyperthermophilic organisms that grow in highly acidic (pH2) habitats belongs to the two groups called

  • eubacteria and archaea

  • cyanobacteria and diatoms

  • protists and mosses

  • protists and mosses


A.

eubacteria and archaea

Thermophiles live in hot places, typically from 60o to 80oC. Many thermophiles (some eubacteria and archaebacteria) are autotrophs and have metabolisms based on sulphur. Some thermophilic archaebacteria form the basis of food webs around deep- sea thermal vents, where they must withstand extreme temperature and pressure. Archaebacteria can grow in highly acidic (pH = 0.7) and very basic (pH= 11) environments.

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The figure given below is a diagrammatic representation of the response of organisms to abiotic factors. What do A, B, and C represent respectively?

  • A
    B
    C

    Conformer

    Regulator

    Partial regulator 

  • A

    B

    C

    Regulator

    Partial regulator

    Conformer

  • A
    B
    C

    Partial regulator

    regulator conformer
  • A
    B
    C

    Partial regulator

    regulator conformer

D.

A
B
C

Partial regulator

regulator conformer

a) Regulator - mammals and birds

b) Conformer - all plants and 99% animals

c) Partial regulators - 

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A country with a high rate of population growth took measures to reduce it. The figure below shows age-sex pyramids of populations. A and B twenty years apart. Select the correct interpretation about them

Interpretations

  • 'A' is more recent and shows slight reduction in the growth rate

  • 'B' is earlier pyramid and shows stabilised

  • 'B' is more recent showing that population is very young

  • 'B' is more recent showing that population is very young


A.

'A' is more recent and shows slight reduction in the growth rate

Interpretation 'A' is correct for the given figures.

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Which one of the following is most appropriately defined?

  • Host is an organism, which provides food to another organism

  • Amensalism is a relationship in which one species is benefited whereas the other is unaffected

  • Predator is an organism that catches and kills other organism for food

  • Predator is an organism that catches and kills other organism for food


C.

Predator is an organism that catches and kills other organism for food

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Which one of the following statemtents about morula in human is correct?

  • It has almost equal quantity of cytoplasm as an uncleaved zygote but much more DNA

  • It has far less cytoplasm as well as less DNA than in an uncleaved zygote

  • It has more or less equal quantity of cytoplasm and DNA as in uncleaved zygote

  • It has more or less equal quantity of cytoplasm and DNA as in uncleaved zygote


D.

It has more or less equal quantity of cytoplasm and DNA as in uncleaved zygote

Cleavage divisions are mitotic division, in which the single -celled zygote is converted into a multicellular morula. But during cleavage divisions, there is no growth of resultant daughter cells/blastomeres. So, the DNA content will increase, but there is no increase or insignificant increase in amount of protoplasm.

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