Cell The Unit Of Life

Q1. Who proposed the fluid mosaic model of plasma membrane?

  1. Benda.
  2. Schleiden and Schwann.
  3. Singer and Nicolson.
  4. Robert Brown.
Click To View The Answer

Ans: 3. Singer and Nicolson.

Explanation:
Fluid mosaic model of plasma membrane was proposed by Singer and Nicolson in 1972. According to this model, the membrane does
not have a uniform position of lipids and proteins but is instead a mosaic of the two. Further, the membrane is not solid but is quasi
fluid. This nature of biomembrane is responsible for properties like repair, dynamic nature, ability to fuse, endocytosis etc. Fluidmosaic model postulates that the lipid molecules are present in a viscous bilayer as in lamellar model. Protein molecules occur at
places both inside and on the outer side of lipid bilayer i.e., protein icebergs in a sea of lipids. The internal proteins are called intrinsic
or integral proteins while the external ones are known as extrinsic or peripheral proteins. Some of the integral proteins run
throughout the lipid bilayer. They are called tunnel proteins or transmembrane proteins. Glycolipids as well as glycoproteins are found
on the external face of lipid bilayer membrane.

Q2. Select one which is not true for ribosome:

  1. Made of two sub-units.
  2. Form polysome.
  3. May attach to m+RNA.
  4. Have no role in protein synthesis.
Click To View The Answer

Ans: 4. Have no role in protein synthesis.

Explanation:
Ribosome is truly called as protein factory and they play a vital role in protein synthesis. Thus, the statement that ribosome’s have no
role in protein synthesis is not true. Other statements are true for ribosome Ribosome’s are made up of two subunits, i.e., large and
small. In prokaryotes it is 70S (50S and 80S). In eukaryotes it is 80S (60S and 40S). Polyribosome’s several ribosomes attach to a single
mRNA and form a chain like structure. Polysomes they are formed by the attachment of ribosome’s with mRNA.

Q3. The fluidity of membranes in a plant in cold weather may be maintained by:

  1. Increasing the number of phospholipids with unsaturated hydrocarbon tails.
  2. Increasing the proportion of integral proteins.
  3. Increasing concentration of cholesterol in membrane.
  4. Increasing the number of phospholipids with saturated hydrocarbon tail.
Click To View The Answer

Ans: 1. Increasing the number of phospholipids with unsaturated hydrocarbon tails.

Q4. Which of the following organisms have a prokaryotic cell?

  1. Cyanobacteria.
  2. Algae.
  3. Fungi.
  4. Amoeba.
Click To View The Answer

Ans: 1. Cyanobacteria.

Q5. The cell organelle not included in the endomembrane system, is:

  1. Endoplasmic reticulum.
  2. Lysosomes.
  3. Mitochondria.
  4. Golgi apparatus.
Click To View The Answer

Ans: 3. Mitochondria.

Q6. In chloroplasts, chlorophyll is present in the.

  1. Outer membrane.
  2. Inner membrane.
  3. Thylakoids.
  4. Stroma.
Click To View The Answer

Ans: 3. Thylakoids.

Q7. Which of the following cell organelle remains enveloped by a single unit membrane?

  1. Lysosomes.
  2. Chloroplast.
  3. Mitochondria.
  4. Nucleus.
Click To View The Answer

Ans: 1. Lysosomes.

Q8. Smooth endoplasmic reticulum is well developed in the cells which synthesize.

  1. Steroids.
  2. Carbohydrates.
  3. Proteins.
  4. All of these.
Click To View The Answer

ns: 1. Steroids.

Q9. Quasi-fluid nature of membrane is due to:

  1. Phospholipid.
  2. Peripheral protein.
  3. Integral protein.
  4. Sugar moiety
Click To View The Answer

Ans: 1. Phospholipid.

Q10. Cell recognition and adhesion are facilitated by components of plasma membrane. These components are
generally.

  1. Glycolipids and glycoproteins.
  2. Both lipids and proteins.
  3. Protein molecules alone.
  4. None of these.
Click To View The Answer

Ans: 1. Glycolipids and glycoproteins.

Q11. The main organelle involved in modification and routing of newly synthesized proteins to their destinations is:

  1. Chloroplast.
  2. Mitochondria.
  3. Lysosome.
  4. Endoplasmic reticulum.
Click To View The Answer

Ans: 4. Endoplasmic reticulum.

Q12. Resolution power is the ability to:

  1. Distinguish two trees.
  2. Distinguish two close objects.
  3. Distinguish amongst organelles.
  4. Magnify image.
Click To View The Answer

Ans: 2. Distinguish two close objects.

Q13. Which organelle is also known as the ‘suicide bag of the cell’?

  1. ER.
  2. Lysosome.
  3. Vacuole.
  4. Plastid.
Click To View The Answer

Ans: 2. Lysosome.

Q14. Which of the following plastids stores proteins?

  1. Amyloplasts.
  2. Elaioplasts.
  3. Aleuroplasts.
  4. Chloroplasts.
Click To View The Answer

Ans: 3. Aleuroplasts.

Q15. In which one of the following is nitrogen not a constituent?

  1. Pepsin.
  2. Idioblast.
  3. Bacteriochlorophyll.
  4. Invertase.
Click To View The Answer

Ans: 2. Idioblast.

Q16. Which of the following stains is not used for staining chromosomes?

  1. Basic Fuchsin.
  2. Safranin.
  3. Methylene green.
  4. Armine.
Click To View The Answer

Ans: 2. Safranin.

Explanation:
Other stains in the option are used for staining chromosomes or nucleus whereas safranin is generally used as counter stain in gram
staining.

Q17. Select the wrong statement from the following:

  1. Both chloroplasts and mitochondria contain an inner and an outer membrane.
  2. Both chloroplasts and mitochondria have an internal compartment, the thylakoid space bounded by the
    thylakoid membrane.
  3. Both chloroplasts and mitochondria contain DNA.
  4. The chloroplasts are generally much larger than mitochondria.
Click To View The Answer

Ans: 2. Both chloroplasts and mitochondria have an internal compartment, the thylakoid space bounded by the thylakoid membrane

Q18. The outer layer of vacuole is called:

  1. Tonoplast.
  2. Leucoplast.
  3. Cell wall.
  4. Plasmalayer.
Click To View The Answer

Ans: 1. Tonoplast.

Q19. The cell organelle which lacks a membrane boundary:

  1. Chloroplast.
  2. Golgi body.
  3. Ribosome.
  4. Mitochondria.
Click To View The Answer

Ans: 3. Ribosome.

Q20. Which of the following plastids stores starch?

  1. Amyloplasts.
  2. Elaioplasts.
  3. Aleuroplasts.
  4. Chloroplasts.
Click To View The Answer

Ans: 1. Amyloplasts.

Q21. Electron microscope has a high resolution power. This is due to:

  1. Electromagnetic lenses.
  2. Very low wavelength of electron beam.
  3. Low wavelength of light source used.
  4. High numerical aperture of glass lenses used.
Click To View The Answer

Ans: 2. Very low wavelength of electron beam.

Q22. Which of the following is part of endomembrane system?

  1. Mitochondria.
  2. Chloroplast.
  3. Chromosome.
  4. Vacuole.
Click To View The Answer

Ans: 4. Vacuole.

Q23. Binding of specific protein on regulatory DNA sequence can be studied by means of:

  1. Ultra centrifugation.
  2. Electron microscope.
  3. Light microscope.
  4. X-rays crystallography.
Click To View The Answer

Ans: 4. X-rays crystallography.

Q24. Protein synthesis in an animal cell takes place.

  1. Only in cytoplasm.
  2. In the nucleolus as well as in the cytoplasm.
  3. In the cytoplasm as well as in mitochondria.
  4. Only on ribosomes attached to nucleus.
Click To View The Answer

Ans: 3. In the cytoplasm as well as in mitochondria.

Q25. Golgi apparatus is absent in:

  1. Higher plants.
  2. Yeast.
  3. Bacteria and blue-green algae.
  4. None of the above.
Click To View The Answer

Ans: 3. Bacteria and blue-green algae.

Q26. Oxysomes or F-F particles occur on:

  1. Thylakoids.
  2. Mitochondrial surface.
  3. Inner mitochondrial membrane.
  4. Chloroplast surface.
Click To View The Answer

Ans: 3. Inner mitochondrial membrane.

Q27. The proteins are synthesized at:

  1. Ribosomes.
  2. Mitochondria.
  3. Centrosomes.
  4. Golgi bodies.
Click To View The Answer

Ans: 1. Ribosomes.

Q28. Cell secretion is done by:

  1. Plastids
  2. ER
  3. Golgi apparatus
  4. Nucleolus
Click To View The Answer

Ans: 3. Golgi apparatus

Q29. All plastids have similar structure because they can:

  1. Store starch, lipids and proteins.
  2. Get transformed from one type to another.
  3. Perform same function.
  4. Be present together.
Click To View The Answer

Ans: 4. Get transformed from one type to another.

Q30. The desmosomes are concerned with.

  1. Cytolysis.
  2. Cell division.
  3. Cell adherence.
  4. Cellular excretion.
Click To View The Answer

Ans: 3. Cell adherence.