Multiple Choice Questions

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Identify the labelled part in the given figure and select the correct option.

  • A - Heterocyst, B - Mucilaginous sheath

  • A - Mucilaginous sheath, B - Heterocyst

  • A - Heterocyst, B - Capsid

  • A - Pseudopodia, B - Mucilaginous sheath


A.

A - Heterocyst, B - Mucilaginous sheath

Heterocysts are specialized nitrogen fixing cells formed during nitrogen starvation by some filamentous cyanobacteria, such as Nostoc punctiforme etc.

Mucilaginous sheath of blue- green algae is to bind colonies together and to permit movement.


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Which of the following is a group of micronutrients for plants?

  • Fe, Mn, Cu, Mo, Zn

  • Fe, Mn, Cu, O, C

  • Cu, B, Cl, Fe, Ca

  • Ca, Mg, Fe


As secondary growth proceeds, in a dicot stem, the thickness of

  • sapwood increases

  • heartwood increases

  • both sapwood and heartwood increases

  • both sapwood and heartwood remains the same


A plasmolysed cell can be deplasmolysed by placing it in

  • isotonic solution

  • saturated solution

  • pure water or hypotonic solution

  • hypertonic solution


The chemiosmotic coupling hypothesis of oxidative phosphorylation proposes that adenosine triphosphate (ATP) is formed because

  • a proton gradient forms across the inner mitochondrial membrane

  • there is a change in the permeability of the inner mitochondrial membrane towards adenosine diphosphate (ADP).

  • high energy bonds are formed in mitochondrial proteins

  • ADP is pumped out of the matrix into the intermembrane space


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Assertion : Gap junctions perform cementing function to keep the neighbouring cells together.

Reason : Tight junctions facilitate the cells to communicate with each other by connecting the cytoplasm of adjoining cells, for rapid transfer of ions, small and big molecules, etc.

  • 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


Assertion : Consciousness is considered as the defining property of living organisms.

Reason : All organisms, from the prokaryotes to the most complex eukaryotes can sense and respond to environmental stimuli.

  • 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 correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


Yeast is not included in protozoans but in fungi because

  • it has chlorophyll

  • it shows saprotrophic mode of nutrition

  • it has eukaryotic organisation

  • cell wall is made up of cellulose and reserve food material as starch


Photosynthesis in C4 plants is relatively less limited by atmospheric CO2 levels because

  • there is effective pumping of CO2 into bundle sheath cells

  • RuBisCO in C4 plants has higher affinity for CO2

  • six carbon acids are the primary initial CO2 fixation products

  • the primary fixation of CO2 is mediated via PEP carboxylase.


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Which one of the following is correct for the transmembrane proteins in lipid bilayer of plasma membrane?

  • They are absent in animal cells

  • They act as channel proteins

  • They are absent in plant cells

  • They are only externally located