Multiple Choice Questions

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Companion cell in plants are associated with

  • vessels

  • sieve elements

  • sperms

  • guard cells


B.

sieve elements

Companion cell A type of cell found within the phloem of flowering plants. Each companion cell is usually closely associated with a sieve element. Its function is uncertain, though it appears to regulate the activity of the adjacent sieve element and to take part in loading and unloading sugar into the sieve element. In gymnosperms a similar function is attributed to albuminous cells, which are found closely associated with gymnosperm sieve elements


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Assertion: In angiosperms the conduction of water is more efficient because their xylem has vessels.

Reason: Conduction of water by vessel elements is an active process with energy supplied by xylem parenchyma rich in mitochondria

  • 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.


Ectophloic siphonostele is found in

  • Osmunda and Equisetum

  • Marsilea and Botrychium

  • Adiantum and Cucurbitaceae

  • Dicksonia and Maiden hair fern


Short Answer Type

What is the difference between pinocytosis and phagocytosis?


Multiple Choice Questions

Assertion : Long distance flow of photoassimilates in plants occurs through sieve tubes.

Reason : Mature sieve tubes have parietal cytoplasm and perforated sieve plates.

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

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

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


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The plant undergoes wilting when

  • xylem is blocked

  • cambium is blocked

  • phloem is blocked

  • some roots are reduced in number


Vascular bundles of roots are

  • conjoint

  • concentric

  • bicollateral

  • radial


Graham's law is correlated with

  • diffusion

  • osmoregulation

  • osmosis

  • absorption


Lenticular transpiration takes place in

  • fruits

  • woody stems

  • leaves

  • all of these


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When the cell is fully turgid, its

  • DPD = OP

  • DPD = zero

  • WP = TP

  • OP = zero


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