PMT Foundation Cell – Structure & Functions
Multiple Choice Questions
1) Zonula adherens is a kind of
(a) filament (b) desmosome
(c) membrane (d) mesosome.
2) Which of the following do not possess lipoproteinaceous membrane?
(a) Lysosomes (b) Lomasomes
(c) Ribosomes (d) Sphaerosomes
3. In mitochondria, cristae act as sites for
(a) protein synthesis
(b) breakdown of macromolecules
(c) oxidation – reduction reaction
(d) phosphorylation of flavoproteins
4. Predominant form of lipid present in biomembranes are
(a) triacylglycerols (b) cholesterol
(c) free fatty acids (d) phospholipids
5. Which of the given statements are correct?
(i) Bacillus subtilis is a Gram (+) bacteria
(ii) Escherichia coli is a Gram (-) bacteria
(iii) Washing of the Gram’s stain in Gram ( – ) bacteria is due to high lipid content of the cell wall, which gets dissolved in organic solvents like acetone.
(a) (i) and (ii) (b) (ii) and (iii)
(c) (i) and (iii) (d) (i),(ii)and(iii)
6. One important component of cytoskeleton is
(a) bone (b) cartilage
(c) microtubules (d) chitin
7. The strength and rigidity of a cell wall is due to
(a) lignin (b) cartilage
(c) pectin (d) cellulose
8. The fluidity of membranes in a plant in cold weather may be maintained by
(a) increasing the number of phospholipids with unsaturated hydrocarbon tails
(b) increasing the proportion of integral proteins
(c) increasing concentration of cholesterol in membrane
(d) increasing the number of phospholipids with saturated hydrocarbon tail
9. Ribosomes of mitochondria and chloroplast are
(a) 30S (b) 80S
(c) 50S (d) 70S
10. Enzyme peptidyl transferase occurs in
(a) larger subunit of ribosome
(b) smaller subunit of ribosome
(c) endoplasmic reticulum
11. Glycocalyx is
(a) glycoproteins and glycolipids
(b) oligosaccharide part of glycolipids and glycoproteins
(c) lipid and protein parts of glycolipids and glycoproteins
(d) mucopolysaccharides attached to cell wall
12. Pollutants and carcinogens are detoxified by
(a) P 4 5 0 a n d P . J 8 (b) SER in liver
(c) RER in liver (d) both (a) and (b)
13. Three of the following statements regarding cell or1ganelles are correct while one is wrong. Which one is wrong?
(a) Lysosomes are single membraned vesicles budded off from Golgi apparatus and contain digestive enzymes
(b) Endoplasmic reticulum consists of a network of membranous tubules and helps in transport, synthesis and secretion.
(c) Leucoplasts are bound by two membranes, lack pigment but contain their own DNA and protein synthesizing machinery.
(d) Sphaerosomes are single membrane bound and are associated with synthesis and storage of lipids
14. Smooth endoplasmic reticulum is found abundantly in
(a) lipid and steroid secreting cells
(b) protein secreting cells
(c) egg cells
15. The nucleoprotein structures that occur at the ends of the chromosome are
(a) centrosomes (b) telomeres
(c) centromeres (d) satellites
True or False
16. Microbodies are minute vesicles that contain various enzymes, present in animal cells only.
17. Satellites are secondary constrictions at a constant location on a few chromosomes, that stain with basic dyes.
18. The ribosomes of the chloroplasts are similar to the chloroplasts present in the cytoplasm of eukayotic cells.
19. Mitochondria are ‘power houses’ of the cell and are sites of both aerobic and anaerobic respiration.
20. In plant cells, the concentration inside the vacuoles is significantly lower than in the cytoplasm.
21 . The endomembrane system includes endoplasmic reticulum, golgi complex, peroxisomes and lysosomes.
22. Polar molecules cannot pass through the nonpolar lipid bilayer.
23. Depending on the staining techniques, the membrane proteins can be classified as integral or peripheral.
24. The smooth endoplasmic reticulum is the major site for synthesis of lipids and is continuous with the outer membrane of the nucleus, as well as the plasma membrane.
25. Lysosomes are rich in all types of hydrolytic enzymes and help in both intracellular and extracellular digestion.
Match the Columns
26. Match Column-I with Column-ll and select the correct option from codes given below.
28.(A) Complete the given passage with appropriate words or phrases.
The _Q_ nucleus has a loose and distinct network of (ii) fibres called ( i i i ) . But during different stages of cell division, cells show structured (iv) in place of nucleus.
Every chromosome has a primary (v) or (vi), on the sides of which disc shaped structures called (vii) are present.
(B) Read the passage and correct the errors, wherever present. The centrosomes in a centriole lie perpendicular to each other, in which, each has an organisation like a car wheel.
Assertion Based Questions
In each of the following questions, a statement of Assertion is given and a corresponding statement of Reason is given just below it. Of the statements, mark the correct answer as :
(a) if both A and R are true and R is the correct explanation of A
(b) if both A and R are true but R is not the correct explanation of A
(c) if A is true but R is false
(d) if both A and R are false
29. Assertion : The quasi-fluid nature of lipid enables lateral movement of proteins within the bilayered cell membrane.
Reason: This ability to move within the membrane is measured as its fluidity.
30. Assertion : Some bacteria develop resistance to certain antibiotics.
Reason : This unique feature is due to their blueprint which is the genomic DNA.
31 . Assertion : Mesosome is an infolding of the cell membrane and increases the surface area of the plasma membrane.
Reason : It is characteristic of prokaryotes, viruses and fungi.
32 . Assertion : The flagella, pili and fimbriae are the surface structures of the bacteria.
Reason : They are all responsible for motility in bacteria.
33 .Assertion : The number of mitochondria per cell is variable depending on the physiological activity of the cells.
Reason : However, the shape and size of mitochondria is constant for all cells.
34. Assertion : The content of the nucleolus is delimited from the nucleoplasm due to the presence of a single nucleolar membrane.
Reason : A small number of large sized nucleoli are present in cells actively carrying out protein synthesis.
35. Assertion : The material of the nucleus can be stained by acidic dyes.
Reason : This is due to the basic nature of the nuclear material.
36. Assertion : The sub-metacentric chromosome has centromere slightly away from the middle of the chromosome.
Reason : Hence, one arm of the chromosome is extremely short, while the other one is very long.
37. Assertion : The perinuclear space lies between the nucleus and the cytoplasm.
Reason : It prevents exchange of materials between the nucleus and the cytoplasm.
38 .Assertion : A single human cell has nearly 2 metre long DNA distributed amongst the 23 pairs of chromosomes.
Reason : Chromatin contains DNA and some basic proteins called histones only.
Figure based Questions
39. (i) Refer to the figure given below. Identify the labelled parts P, Q, R, S and T.
(ii) The arrangement of P and Q is called .
40. Refer to the figure again and fill in the blanks using appropriate alphabets of the labelled parts – P, Q, R, S, T.
(i) The (i) are connected by bridges and enclosed by (iii), which is connected to one of the tubules of each (iii) by a (iv).
1.(b) 2.(c) 3.(c) 4.(d) 5.(d)
6.(c) 7.(a) 8.(a) 9.(d) 10.(a)
11.(b) 12.(d) 13.(c) 14.(a) 15.(b)
16. False. Microbodies are present in both plant and animal cells.
17. False. Satellites are non-staining secondary
18. False. The ribosomes of chloroplasts are smaller, 70S, while cytoplasmic ribosomes are 80S.
19 False. The mitochondria are the sites for aerobic respiration only.
20. False. The concentration in the plant vacuoles is significantly higher than in the cytoplasm.
21. False . The endomembrane system includes endoplasmic reticulum, golgi complex, lysosomes and vacuoles.
23. False . Depending on the ease of extraction, membrane proteins can be classified as integral or peripheral.
24. False. The rough endoplasmic reticulum is continuous with the outer membrane of the nucleus, while the smooth endoplasmic reticulum is peripheral and connected with plasma membrane.
26. A-(vi), B-(iii), C-(iv), D-(v), E-(vii), F-(ii), G-(i)
27. A-(i, xiv), B-(x, xiii), C-(ii, xi), D-(v, ix), E-(iv, vii), F-(vi, viii), G-(iii, xii)
28.(A) (i) interphase, (ii) nucleoprotein, (iii) chromatin, (iv) chromosomes, (v) constriction, (vi) centromere, (vii) kinetochores.
(B) The centrosomes centrioles in a centriole centrosome lie perpendicular to each other, in which, each has an organisation like a carwheel cartwheel.
29. (b) 30. (c) 31. (c) 32. (c) 33. (c)
34. (d) 35. (d) 36. (c) 37. (d) 38. (b)
39. (i) P – Peripheral microtubules or doublets;
Q – Central microtubule; R – Interdoublet bridge;
S – Radial spoke; T – Central sheath
(ii) 9 + 2
40. (i) Q; (ii) T; (iii) P; (iv) S