Multiple Choice Questions

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The translocation of organic solutes in sieve tube members is supported by

  • root pressure and transpiration pull

  • P-proteins

  • mass flow involving a carrier and ATP

  • mass flow involving a carrier and ATP


C.

mass flow involving a carrier and ATP

According to mass flow hypothesis, the transport of organic solutes takes place from source to sink this transport also depends on metabolic energy.
According to cytoplasmic streaming hypothesis (put forward by de Vries 1885) the transport of organic solutes takes place by combination of diffusion and cytoplasmic streaming.
Cytoplasmic streaming carry organic solutes from one end the other end of sieve tube.
P proteins has a role as defence against phloem-feeding insects and sealing of damaged sieve tubes.
Protein is absent in monocots and gymnosperms.

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Two cells A and B are contiguous. Cell A has osmotic pressure 10 atm, turgor pressure 7 atm and diffusion pressure deficit 3 atm. Cell B has osmotic pressure 8 atm, turgor pressure 3 atm and diffusion pressure deficit 5 atm. The result will be

  • Movement of water from cell B to A

  • No movement of water

  • Equilibrium between the two

  • Equilibrium between the two

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Which of the following is made up of dead cells?

  • Xylem parenchyma

  • Collenchyma

  • Phellem

  • Phellem

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Which of the following facilitates opening of stomatal aperture?

  • Contraction of outer wall of guard cells

  • Decrease in turgidity of guard cells

  • Radial orientation of cellulose microfibrils in the cell wall of guard cells

  • Radial orientation of cellulose microfibrils in the cell wall of guard cells

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The water potential of pure water is

  • Zero

  • Less than zero

  • More than zero but less than one

  • More than zero but less than one

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Which of the following elements is responsible for maintaining turgor in cells?

  • Magnesium

  • Sodium

  • Calcium

  • Potassium


Stomatal movement is not affected by

  • Temperature

  • Light

  • CO2 concentration

  • O2 concentration


Some functions of the nutrient element are given below

  1. Important constituent of proteins involved in ETS.
  2. Activator of catalase.
  3. Important constituent of cytochrome
  4. Essential for chlorophyll synthesis

The concerned nutrient is

  • Cu

  • Fe

  • Ca

  • Mo


Tyloses an outgrowth from ray or axial parenchyma cell into the lumen of a vessel, which partially or completely blocks the cavity are present in

  • Periderm

  • Heart wood

  • Sap wood

  • Secondary cortex


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In which form does the food is transported in plants?

  • Sucrose

  • Fructose

  • Glucose

  • Lactose


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