Biology · Science General
Cell Biology and Structure
3,221 Questions
Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.
Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components
Cell Biology and Structure Questions
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The cells vary in size and shape considerably.
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Granular cytoplasm
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Every cell accomodaes either one or two large and prominent vacuoles, which are storage bubbles found in cells.
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The cell wall may be either thin or thick.
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Absence of ergastic substances
E
Correct answer
Explanation
Ergastic substances are virtually present in the form of secretory products or storage products or excretory products.
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thicker than the outer wall
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thinner than the outer wall
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of same thickness as the outer wall
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Absent
A
Correct answer
Explanation
The cell walls of guard cells are unevenly thickened. The inner wall is thicker than the outer wall.
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Epithem are the kidney shaped cells regulating the opening and closing of stomatal aperture.
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Epithem are the epidermal cells surrounding the guard cells.
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Epithem are the loose tissues present below hydathodes.
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Epithem is the watery sap secreted from injured or cut plant.
C
Correct answer
Explanation
Epithem are the loose tissues present below the hydathodes.
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Sphaerosomes
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Macrosomes
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Peroxysomes
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Microsomes
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Glyoxysomes
E
Correct answer
Explanation
Glyoxysomes are meant for degradation of fat.
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Only a
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Only a and b
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Only b
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Only b and c
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Only c
E
Correct answer
Explanation
This is the correct option as cell wall is not a determinant of the movement of molecules in or out of the cell. The cell wall is freely permeable and is not a barrier to movement.
C
Correct answer
Explanation
The pH of lysosomes is 4.5. At this acidic pH, all the lysosomal enzymes are functional.
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Studies on acid phosphatase
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Studies on glucose-6-phosphate
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Studies on fructose-6-phosphate
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Studies on pyruvate dehydrogenase
B
Correct answer
Explanation
Studies on glucose-6-phosphate in 1949 led to serendipitous discovery of lysosomes.
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golgi apparatus
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rough endoplasmic reticulum
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smooth endoplasmic reticulum (SER)
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nucleus
B
Correct answer
Explanation
Enzymes of the lysosomes are synthesised in the rough endoplasmic reticulum.
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D-mannose
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dianhydroglucopyranoses
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mannose-6-phosphate
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fructose-6-phosphate
C
Correct answer
Explanation
Lysosome enzymes are specifically tagged with the molecule mannose 6-phosphate to differentiate them from other enzymes.
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Bacteria
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Macro-molecules
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Unwanted cell organelles
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Fungal spores
B
Correct answer
Explanation
Macro-molecules undergo endocytosis by lysosomes.
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Lysis of cytosolic organelles
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No effect on cytosolic organelles
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Change of pH of cytoplasm to 4.5
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Increase in respiration
B
Correct answer
Explanation
Leakage of the hydrolytic enzymes would have no effect on cytosolic organelles.
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Na+/Ca2+ exchanger
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ClC-7 Cl−/H+ antiporter
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vacuolar H+ ATPases porter
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Na+/H+ antiporter
C
Correct answer
Explanation
Vacuolar H+-ATPases are responsible for transport of protons from cytosol to lysosome for maintaining pH.
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Endosome
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Vacuole
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Peroxisome
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Secretory vesicle
A
Correct answer
Explanation
The late endosome itself can eventually grow into a mature lysosome.
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both perform catabolic activity
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both perform autophagy
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both have phagocytic function
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both undergo exocytosis
B
Correct answer
Explanation
Both animal lysosomes and some plant vacuoles perform autophagy.
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Intermediate filaments
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Microtubules
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Actin filaments
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FtsZ
C
Correct answer
Explanation
Actin filaments play a critical role in vacuolar trafficking at the Golgi complex in plant cells.