Microtubules are absent in
mitochondria
centriole
flagella
spindle fibres
Correct Answer :
A. mitochondria
Microtubules occur in the cytoplasm of all eukaryotic cells. Besides cytoplasm, microtubules occur in many specialized cellular structures like cilia, flagella, basal bodies, centrioles, astral rays, spindle apparatus, chromosome fibres etc.
Related Questions
Grana are
protein storing plastids.
coloured plastids.
stacks of thylakoids.
individual thylakoids present in stroma.
In prokaryotes, chromatophores are
specialized granules responsible for colouration of cells
structures responsible for organizing the shape of the organism.
inclusion bodies lying free inside the cells for carrying out various metabolic activities.
internal membrane system which becomes extensive and complex in photosynthetic bacteria.
Which of the following statement is correct regarding vacuole?
It is membrane-bound and contains storage proteins and lipids.
It is membrane-bound and contains water and excretory substances.
It lacks membrane and contains air.
It lacks membrane and contains water and excretory substances.
Match column-I (cell organelle) with column-II membrane and select the correct option from the codes given below.
| Column-I | Column-II |
|---|---|
| A. Mitochondria | I. Without membrane |
| B. Lysosomes | II. Single membrane |
| C. Ribosomes | III. Double membrane |
A - I, B - II, C - III
A - III, B - I, C - II
A - III, B - II, C - I
A - II, B - III, C - I
The membrane of the erythrocytes has approximately ___% of proteins and ___% lipids.
42, 50
52, 40
50, 50
60, 40
Read the folowing statements and identify the correct option.
- Contractile vacuole takes part in osmoregulation and excretion.
- Food vacuole is formed by engulfing the food particles.
- The vacuole is bound by a double membrane called tonoplast.
- Vacuole can occupy upto 90 percent of the volume of the cell.
(i) and (ii)
(ii) and (iv)
(i), (ii) and (iv)
None of the above
The main organelle involved in modification and routing of newly synthesized proteins to their destinations is
chloroplast
mitochondria
lysosome
endoplasmic reticulum
Choose the wrong statements regarding bacterial cell
- Glycocalyx is the outermost envelope in bacteria.
- The glycocalyx could be a loose sheath called capsule.
- The glycocalyx may be thick and tough called slime layer.
- A special structure formed by the plasma membrane is called mesosome.
- Small bristle like fibres sprouting out of the cell are called fimbriae.
(i) and (iii)
(i) and (ii)
(ii) and (iii)
(i) and (iv)
The cell theory was given in year 1839 by Schleiden and Schwann. According to this theory all organisms are composed of cell and cells are the basic unit of life.
How did this theory help in the field of science?
It helped to study the working of cells.
It helped in curing diseases caused by cell.
It helped in restating the earlier theories on cell.
It helped in introducing the use of microscopes to study cell.
Which of the following statements is/are correct ?
- The shape of the cells may vary with the function they perform.
- Human RBC is about 7.0 ??m in diameter.
- Cytoplasm is the main area of cellular activities.
- Various chemical reactions occur in cytoplasm to keep the cell in the living state.
(i), (ii), (iii) and (iv)
Only (i) and (ii)
Only (iv)
None of the above
In which of the following the cells are held together by a Ca-pectate layer?
Primary cell wall
Secondary cell wall
Middle lamella
Tertiary cell wall
Which one of the following is not considered as part of the endomembrane system?
Golgi complex
Peroxisome
Vacuole
Lysosome
pH of vacuolar cell sap is
neutral and isotonic.
alkaline and isotonic.
acidic and hypertonic.
equal to cytoplasm and isotonic.
Extension of plasma membrane in prokaryotic cell is
mesosome
haploid
ribosome
none of these
According to widely accepted fluid mosaic model cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect?
Proteins in cell membranes can travel within the lipid bilayer.
Proteins can also undergo flip-flop movements in the lipid bilayer.
Proteins can remain confined within certain domains of the membrane.
Many proteins remain completely embedded within the lipid bilayer.
Which one of the following structures between two adjacent cells is an effective transport pathway?
Plasmodesmata
Plastoquinones
Endoplasmic reticulum
Plasmalemma
_______________ is the important site of formation of glycoproteins and golycolipids.
SER
Lysosome
Golgi apparatus
Mitochondria
Identify the components labelled as A, B, C, D and E in the diagram given below from the list (i) to (viii).
- Cristae of mitochondria
- Inner membrane of mitochondria
- Cytoplasm
- Smooth endoplasmic reticulum
- Rough endoplasmic reticulum
- Mitochondrial matrix
- Ribosome
- Nucleus
A - (viii), B - (v), C - (vii), D - (iii), E - (iv)
A - (i), B - (iv), C - (vii), D - (vi), E - (iii)
A - (vi), B - (v), C - (iv), D - (vii), E - (i)
A - (v), B - (i), C - (iii), D - (ii), E - (iv)
The fluidity of membranes in a plant in cold weather may be maintained by
increasing the number of phospholipids with unsaturated hydrocarbon tails.
increasing the proportion of integral proteins.
increasing concentration of cholesterol in membrane.
increasing the number of phospholipids with saturated hydrocarbon tail.
Membranous extensions in blue green algae are known as
phytochrome
chromatophore
mesosome
pneumatophore
Which function is carried out by the cell organelle 'X'?
helps control the movement of substance in and out of the cell
passes information from the parent cell to newly formed cell
maintains the proper shape of the cell and serves as a protective barrier
helps the cell to make food with the help of chlorophyll and sunlight
Protein synthesis in an animal cell occurs
on ribosomes present in cytoplasm as well as in mitochondria.
on ribosomes present in the nucleolus as well as in cytoplasm.
only on ribosomes attached to the nuclears envelope and endoplasmic reticulum.
only on the ribosomes present in cytosol.
Identify the cell organelle given below. Which is an important site of formation of glyeoproteins & glycolipids
Rough endoplasmic reticulum
Smooth endoplasmic reticulum
Golgi body
mitochondria
The diagram given below represent a filuid mosaic model of plasma membrance. Match the components marked as A, B, C, D and E in the diagram below from the list (i) to (vii).
- Sugar
- Protein
- Lipid bilayer
- Integral protein
- Cytoplasm
- Cell wall
- External protein
A - (i), B - (ii), C - (iii), D - (iv), E - (v)
A - (ii), B - (i), C - (iii), D - (iv), E - (v)
A - (i), B - (ii), C - (iii), D - (iv), E - (vi)
A - (i), B - (ii), C - (iii), D - (vii), E - (v)
Lysosomes contain
carbohydrates
hormones
nucleic acids
hydrolases.
Which of the following statements are incorrect ?
- Plant cells have centrioles which are absent in almost all animal cells.
- Ribosomes are the site of protein synthesis.
- The middle lamella is a layer mainly of calcium carbonate which holds the different neighbouring cells together.
- In animal cell, steroidal hormones are synthesized by smooth endoplasmic reticulum. Of the above statements
(i) and (iii)
(iii) and (iv)
(ii) and (iv)
(i) and (iv)
Which one of the following pairs is not correctly matched?
Cristae The tubular structure formed by the folding of the inner membrane of the mitochondrion.
Plasmodesmata The membrane surrounding the vacuole in plants.
Grana Membrane bound discs in chloroplasts that contain chlorophylls and carotenoids.
Middle lamella Layer between adjacent cells walls in plants derived from cell plate.
Which one of the following organelle given below is correctly matched with its function ?
Golgi apparatus Protein synthesis
Golgi apparatus Formation of glycolipids
Rough endoplasmic reticulum Protein synthesis
Rough endoplasmic reticulum Formation of glycoproteins
Who proposed the theory that Cells arise only from the pre-existing cells?
Mohl
Virchow
Haeckel
Brown
Match column-I (scientists) with column-II (discovery) and select the correct option.
| Column-I | Column-II |
|---|---|
| A. Leeuwenhoek | I. First saw and described a living cell |
| B. Robert Brown | II. Presence of cell wall is unique to plant cells |
| C. Schleiden | III. Discovered the nucleus |
| D. Schwann | IV. All plants are composed of different kind of cells |
A I, B III, C IV, D II
A I, B III, C II, D IV
A III, B I, C IV, D II
A I, B IV, C II, D III