Multiple Choice Questions

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Stomata of CAM plants

  • open during the night and close during the day

  • never open

  • are always open

  • open during the day and close at night


A.

open during the night and close during the day

CAM (Crassulacean Acid Metabolism) plants open stomata only at night (when temperature is low and humidity is high) to cause lesser loss of water (eg, Agave, Opuntia, etc).


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In sugarcane plant, 14CO2 is fixed in a malic acid, in which the enzyme that fixes CO2 is

  • ribulose phosphate kinase

  • fructose phosphatase

  • ribulose biphosphate carboxylase

  • phosphoenol pyruvic acid carboxylase


Which one of the following is wrong in relation to photorespiration?

  • It is a characteristic of C4 -plants

  • It is a characteristic of C3 -plants

  • It occurs in chloroplasts

  • It occurs in daytime only


Which one of the following is categorised under living fossils?

  • Selaginella

  • Metasequoia

  • Pinus

  • Cycas


Mycorrhiza is an example of

  • endoparasitism

  • decomposers

  • symbiotic relationship

  • ectoparasitism


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Chlorenchyma is known to develop in the

  • spore capsule of a moss

  • pollen tube of Pinus

  • cytoplasm of Chlorella

  • mycellium of a green mould such as Aspergillus


Boron in green plants assists in

  • photosynthesis

  • sugar transport

  • activation of enzymes

  • acting as enzyme cofactor


Cessation of menstrual cycle in women is called

  • menopause

  • lactation

  • ovulation

  • parturition


Barr-body in mammals represents

  • one of the two X-chromosomes in the cells

  • all heterochromatin of male and female cells

  • Y-chromosome of male

  • all heterochromatin of female cells


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Discontinuous variations are

  • essential features

  • acquired character

  • non-essential changes

  • heritable changes