Multiple Choice Questions

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What is correct about the movement of substance across the membrane in facilitated diffusion?

  • It is an active transport

  • It doesn't cause transport of molecules from low concentration to high concentration

  • It is insensitive to inhibitors

  • It is a very specific transport


D.

It is a very specific transport

In facilitated diffusion special proteins help move substances across membranes along the concentration gradient without expenditure of energy. It is very specific, it allows cell to select substances for uptake. It is sensitive to inhibitors which react with protein side chains.


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

  • Pteridophytes

  • Angiosperms

  • Gymnosperms

  • Bryophytes


Vitamin B6 is also called

  • thiamine

  • pantothenic acid

  • pyridoxine

  • retinol


Protista differs from monera in having

  • cell wall

  • autotrophic nutrition

  • flagella

  • nuclear membrane


Refer the given figures on photoperiodism and select the correct option.

  • A B C
    no correlation between light period and flowering long light- exposure period short light- exposure period
  • A B C
    long light- exposure period no correlation between light period and flowering short light- exposure period
  • A B C
    short light exposure period long light exposure period no correlation between light period and flowering
  • A B C
    no correlation between light period and flowering short light exposure period long light exposure period

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Which of the following is correct about the given figure?

  • The length ofthe thick and thin myofilaments has changed.

  • Length of both anisotropic and isotropic band has changed.

  • The myosin cross-bridges move on the surface of actin and the thin and thick myofilaments slide past each other.

  • Length of the sarcomere remains same.


Which of the following is correct?

  • Paneth cells secrete pepsinogen

  • Parietal cells secrete hydrochloric acid

  • Argentaffin cells secrete mucus

  • Chief cells secrete gastrin


What do A, B, C and D represent in the following figure?

  • A : carrier protein, B: symport, C: uniport, D : antiport

  • A : carrier protein, B : uniport, C: antiport, D : symport

  • A: carrier protein, B: antiport, C: symport, D : uniport

  • A : carrier protein, B: uniport, C: symport, D : antiport


Who invented electron microscope?

  • Janssen

  • Edison

  • Knoll and Ruska

  • Landsteiner


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Why are vascular bundles closed in monocots?

  • Xylem and phloem are present.

  • Xylem and phloem occur in separate bundles.

  • Vascular cambium is present between xylem and phloem.

  • Vascular cambium is not present.