96 Topicwise Solved Previous Year Qs Cell: The Unit of Life intracellular digestion of...

Topicwise Solved Previous Year Qs 96

Cell: The Unit of Life

1. According of fluid mosaic model,

plasma membrane is composed of [1988] (a) phospholipids and oligosaccharides

(b) phospholipids and hemicellulose (c) phospholipids and integral proteins

(d) phospholipids, extrinsic proteins and intrinsic proteins

Solution: (d) According to fluid mosaic model proposed

by Singer and Nicolson (1972, 74), plasma

membrane is composed of phospholipid bilayer and protein. Protein molecules

occur at places both inside and outside of lipid bilayer. The internal proteins are

called intrinsic proteins and the external proteins are called extrinsic proteins.

2. Acetabularia used in Hammerling‘s

nucleocytoplasmic experiments is [1988]

(a) unicellular fungus (b) multicellular fungus

(c) unicellular uninucleate green algae (d) unicellular multinucleate green algae

Solution: (c) Acetabularia used in Hammerling‘s

nucleocytoplasmic experiments is

unicellular uninucleate marine green alga.

3. Organelles can be separated from cell homogenate through [1989]

(a) chromatography (b) X-rays diffraction

(c) differential centrifugation (d) auto-radiography

Solution: (c) Centrifuge is an instrument used to create a centrifugal force. The homogenate of the

cell organelles is allowed to undergo centrifugation by which different cell

organelles get separated. The process is known as differential centrifugation.

4. Plasma membrane is made of [1989]

(a) proteins and carbohydrates

(b) proteins and lipids (c) proteins, lipids and carbohydrates

(d) proteins, some nucleic acid and lipids Solution: (c) Plasma membrane is made up of proteins, lipids and carbohydrates. Carbohydrates

are covalently linked to both lipid and

protein.

5. Polyribosomes are aggregates of [1989]

(a) ribosomes and rRNA (b) only rRNA

(c) peroxisomes (d) several ribosomes held together by

string of mRNA

Solution: (d) Polyribosomes consists of 4-8 ribosomes

which are attached to a single strand of mRNA. This mechanism help in synthesis

of several copies of the same protein.

6. Nucleoproteins are synthesised in

[1989] (a) nucleoplasm

(b) nuclear envelope (c) nucleolus

(d) cytoplasm Solution: (d) Nucleoproteins are conjugated proteins. They are deoxyribonucleoproteins and

ribonucleoproteins synthesised in

cytoplasm of the cell.

7. A bivalent consists of [1989] (a) two chromatids and one centromere

(b) two chromatids and two centromeres (c) four chromatids and two centromeres

(d) four chromatids and four centromeres Solution: (c) A pair of homologus chromosomes lying

together in the zygotene stage of Prophase I of first meiotic division is called a bivalent.

8. Magnification of compound

microscope is not connected with [1990] (a) numerical aperture

(b) focal length of objective

(c) focal length of eye piece (d) tube length

Solution: (a) Magnification is defind as the power of

enlargement. Magnification of compound microscope is the product of magnification

of objective lens and magnification of ocular lens.

9. The latest model for plasma membrane is [1990]

(a) lamellar model


(b) unit membrane model

(c) fluid mosaic model (d) molecular lipid model

Solution: (c) Fluid mosaic model is the most recent

model of a biomembrane proposed by Singer and Nicolson (1972, 74). According

to this model, the membrane does not have a uniform deposition of lipids which are

present as highly viscous fluid matrix of

two layers of phospholipid moles and proteins arranged in a symetrical pattern.

10. Hammerling‘s experiments of

Acetabularia involved exchanging [1990] (a) cytoplasm

(b) nucleus

(c) rhizoid and stalk (d) gametes

Solution: (c) J. Hammerling (1934) conducted

experiments using two species of green algae Acetabularia crenulata and A.

mediterranea. They differ in the shapes of

their caps. The nucleus in both species is situated in rhizoid at the bottom of stalk. If

after removing cap, stalk of one species is grafted on rhizoid of the other species,

shape of the cap will be determined by nucleus, not by the stalk. This experiment

makes clear that the characters of an individual are controlled by nucleus.

11. Electron microscope has a high resolution power. This is due to [1990,

92] (a) electromagnetic lenses

(b) very low wavelength of electron beam (c) low wavelength of light source used

(d) high numerical aperture of glass lenses used

Solution: (b) The resolution is a power of a microscope to distinguish between two particles that

are closely situated. Electron microscope has high resolution power due to very low

wavelength of electron beam.

12. Resolution power is the ability to [1991]

(a) distinguish two close points (b) distinguish two close objects

(c) distinguish amongst organelles (d) magnify image

Solution: (b) The ability to distinguish two close objects

is called resolution power.

13. Fluid mosaic model of cell

membrane was put forward by [1991] (a) Danielli and Davson

(b) Singer and Nicolson (c) Garner and Allard

(d) Watson and Crick

Solution: (b) Fluid Mosaic Model of cell membrane was

put forward by Singer and Nicolson.

14. Ribosomes were discovered by [1991] (a) Golgi

(b) Porter (c) De Robertis

(d) Palade

Solution: (d) Ribosomes were discovered by Robinson

and Brown in plant cell and palade in animal cell.

15. Cell wall shows [1991]

(a) complete permeability (b) semipermeability

(c) differential permeability

(d) impermeability Solution: (a) Cell wall shows complete permeability because it helps in the transport of

substances in and out of the cell.

16. Addition of new cell wall particles

amongst the existing ones is [1991] (a) deposition

(b) apposition (c) intussusception

(d) aggregation Solution: (c) Growth of cell wall occurs by two methods: (i) Intussusception: When the primary wall

is stretched, the materials of secondary

wall are secreted by protoplam deposited within it. (ii) Apposition: Materials of

secondary wall secreted by protoplam are

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deposited in the form of thin layer one

above the other.

17. Angstrom (Å) is equal to [1992] (a) 0.01 mm

(b) 0.001 mm (c) 0.0001 mm

(d) 0.00001 mm Solution: (c) Angstrom Å = 0.0001 µm 1Å = 10–10 m =

10–8cm = 10–7 mm = 10–4 mm

18. Ribosomes are the centre for [1992] (a) respiration

(b) photosynthesis (c) protein synthesis

(d) fat synthesis

Solution: (c) Ribosomes are the workhouses of protein

biosynthesis, the process of translating messenger RNA (mRNA) into protein. The

mRNA comprises a series of codons that dictate to the ribosome the sequence of the

amino acids needed to make the protein. Using the mRNA as a template, the

ribosome translates each codon of the

mRNA, pairing it with the appropriate amino acid. This is done using molecules of

transfer RNA (tRNA) containing a complementary anticodon on one end and

the appropriate amino acid on the other.Protein synthesis begins at a start

codon near the 5‘ end of the mRNA.

19. Oxysomes of F0 – F1 particles occur

on [1992] (a) thylakoids

(b) mitochondrial surface (c) inner mitochondrial membrane

(d) chloroplast surface Solution: (c) The inner membrane of mitochondria

possess small tennis racket like particles called elementary particle, F0 – F1 particles

or oxysomes. There are 1 × 104 – 1 × 105 oxysomes in a mitochondria.

20. All plastids have similar structure

because they can [1992] (a) store starch, lipids and proteins

(b) get transformed from one type to

another (c) perform same function

(d) be present together

Solution: (b) All plastids are similar in structure. So they can easily get transformed from one

type to another. Depending upon the colours there are three types of plastids-

leucoplasts, chromoplasts and chloroplasts.

21. An outer covering membrane is

absent over [1992]

(a) nucleolus (b) lysosome

(c) mitochondrion (d) plastid

Solution: (a) A covering membrane is absent around

nucleolus. Calcium seems to be essential

for maintaining its configuration.

22. Which one is apparato reticolare? [1992]

(a) Golgi apparatus (b) Endoplasmic reticulum

(c) Microfilaments (d) Microtubules

Solution: (a)

23. Experiments on Acetabularia by Hammerling proved the role of [1992]

(a) cytoplasm in controlling differentiation (b) nucleus in heredity

(c) chromosomes in heredity (d) nucleo-cytoplasmic ratio

Solution: (b) Presence of hereditary information in the nucleus was proved by the work of

Hammerling on single celled alga Acetabularia.

24. Glycogen is a polymer of [1992]

(a) galactose

(b) glucose (c) fructose

(d) sucrose Solution: (b) Glycogen is an animal starch, stored in the liver and is polysaccharide of a-Glucose.

About 30,000 glucose molecules joined by 1-4 a-glycosidic bonds and its branches by

1-6 glycosidic bonds. It gives red colour

with iodine solution. • Galactose is a monosaccharide from milk. • Fructose is a


monosaccharide from fruit. • Sucrose is a

disaccharide (Glucose + Fructose)

25. Binding of specific protein on regulatory DNA sequence can be studied

by means of [1993] (a) ultra centrifugation

(b) electron microscope (c) light microscope

(d) X-ray crystallography

Solution: (d) X-ray crystallography is a technique to

study the binding of specific protein on regulatory DNA. X-ray crystallography or

single-crystal X-ray diffraction is an analytical technique which uses the

diffraction pattern produced by bombarding

a single crystal with X-rays to solve the crystal structure. The diffraction pattern is

recorded and then analyzed or ―solved‖ to reveal the nature of the crystal. This

technique is widely used in chemistry and biochemistry to determine the structures of

an immense variety of molecules, including inorganic compounds, DNA, and proteins.

26. Names of Schleiden and Schwann are associated with [1993]

(a) protoplasm as the physical basis of life (b) cell theory

(c) theory of cell lineage (d) nucleus functions as control centre of

cell Solution: (b) Cell theory was proposed by Schleiden and

Schwann (1839) according to which ―All living organisms are composed of cells.‖

Cell theory is also known as cell principle, cell doctrine etc.

27. Which is correct about cell theory in

view of current status of our knowledge

about cell structure [1993] (a) It needs modification due to discovery of

subcellular structures like chloroplasts and mitochondria

(b) Modified cell theory means that all living beings are composed of cells capable of

reproducing (c) Cell theory does not hold good because

all living beings (e.g., viruses) do not have

cellular organisation

(d) Cell theory means that all living objects

consist of cells whether or not capable of reproducing

Solution: (c) The exceptions of cell theory is viruses

which do not possess a cellular machinery. They consists of DNA or RNA core

surrounded by a protein sheath and lack cellular organisation.

28. In salivary gland chromosomes/polytene chromosomes,

pairing is [1993] (a) absent

(b) occasional (c) formed between nonhomologous

chromosomes

(d) formed between homologous chromosomes

Solution: (d) In salivary gland chromosomes/ polytene

chromosomes, somatic pairing is formed between homologous chromosomes and

repeated replication of their chromonemata.

29. Cell recognition and adhesion occur due to biochemicals of cell membranes

named [1993] (a) proteins

(b) lipids (c) proteins and lipids

(d) glycoproteins and glycolipids Solution: (d) Cell recognition and adhesion occur due to

biochemicals of cell membranes named glycoproteins and glycolipids. These are

formed due to the small carbohydrate molecules present on lipids and extrinsic

protein.

30. Golgi apparatus is absent in [1993]

(a) higher plants (b) yeast

(c) bacteria and Solution: (c) Golgi complex is absent in prokaryotic cell i.e (PPLO, bacteria and blue green algae). It

is present in all eukaryotic cells except sieve tubes of plants, sperms of bryophytes

and pteridophytes and red blood

corpuscles.


31. Membranous bag with hydrolytic

enzymes which is used for controlling intracellular digestion of macro -

molecules is [1993, 94] (a) endoplasmic reticulum

(b) nucleosome (c) lysosome

(d) phagosome Solution: (c) Lysosomes are membranous bag with

hydrolytic enzymes which is used for controlling intracellular digestion of macro-

molecules.

32. In plant cells, peroxisomes are associated with [1993]

(a) photorespiration

(b) phototropism (c) photoperiodism

(d) photosynthesis Solution: (a)

In plant peroxisomes are associated with photorespiration. Peroxisomes are

ubiquitous organelles in eukaryotes that function to rid the cell of toxic substances.

They have a single membrane that

separates their contents from the cytosol (the internal fluid of the cell) and that

contains membrane proteins critical for various functions, such as importing

proteins into the organelles and aiding in proliferation. Unlike lysosomes, which are

formed in the secretory pathway, peroxisomes usually self-replicate by

enlarging and then dividing, although there

is some indication that new ones may be formed directly. Peroxisomes were

discovered by the Belgian cytologist Christian de Duve in 1965

33. Balbiani rings (puffs) are sites of

[1993]

(a) DNA replication (b) RNA and protein synthesis

(c) synthesis of polysaccharides (d) synthesis of lipids

Solution: (b) In the region of Balbiani ring the DNA

strands uncoil, become active and produce number of copies of messenger RNA.

34. Inner membrane convolutions of a mitochondrion are known as [1994]

(a) lamellae

(b) thylakoids

(b) grana (d) cristae

Solution: (d) The inner membrane of mitochondria is

infolded to form involutions called cristae. They are meant for increasing the active

area of the inner membrane.

35. Mitochondrial cristae are sites of

[1994] (a) breakdown of macromolecules

(b) protein synthesis (c) phosphorylation of flavoproteins

(d) oxidation-reduction reactions Solution: (d) Mitochondrial cristae possess small

particles called elementary particles which contain ATP- ase. Therefore, they are the

centes of ATP synthesis during oxidative - phosphorylation.

36. Organelle having flattened

membrane bound cisternae and lying near the nucleus is [1994]

(a) golgi apparatus

(b) mitochondrion (c) centriole

(d) nucleolus Solution: (a) Organelle having flattened membrane bound cisternae and lying near the nucleus

is Golgi apparatus.

37. Series of reactions which can

convert fatty acids to sugars in plants but not in animals is [1994]

(a) krebs cycle (b) glyoxylate cycle

(c) ornithine cycle (d) glycolysis

Solution: (b) Several plant structures e.g. pollen, seeds contain fats. The fats are hydrolysed and

consumed as source of energy. This is accomplished through oxidative

degradation called glyoxylate cycle.

38. Auxetic growth is [1994] (a) increase in cell volume only

(b) increase in cell number only

(c) increase in fatty tissue (d) increase in intercellular material

Solution: (a)


Three types of growth are present in

multicellular animals: (i) Auxetic growth: Increase in cell volume only not in number.

(ii) Multiplication growth: Increase in number not in volume. (iii) Accretionary

growth: Growth is due to mitotic division of some special type of cells occurring in

specific locations of body.

39. The prokaryotic flagella possess

[1995] (a) unit membrane enclosed fibre

(b) protein membrane enclosed fibre (c) ‗9 + 2‘ membrane enclosed structure

(d) helically arranged protein molecule Solution: (d) The prokaryotic flagellum is single

stranded made up of several parallel protein fibrils and helical in shape while in

eukaryotes it is made up of axonema and sheath.

40. The function of rough endoplasmic

reticulum is [1995]

(a) fat synthesis (b) lipid synthesis

(c) protein synthesis (d) steroid synthesis

Solution: (c) Rough endoplasmic reticulum bears

ribosomes on its outer surface. These ribosomes take part in protein synthesis.

41. The point, at which polytene chromosomes appears to be attached

together, is called [1995] (a) centriole

(b) centromere (c) chromomere

(d) chromocentre Solution: (d) Granules of condensed chromatin

(heterochromatin), are found scattered in interphase nuclei. At chromocentre, the

polytene chromosomes appear attached.

42. The desmosomes are concerned with

[1995] (a) cytolysis

(b) cell division (c) cell adherence

(d) cellular excretion Solution: (c) Desmosomes are cementing substances, which adhere to each other and keep the

latter tightly packed and they also prevent

leakage of fluid from interphase.

43. Lysosomes have a high content of [1996, 2000]

(a) hydrolytic enzymes (b) lipoproteins

(c) polyribosomes

(d) DNA ligases Solution: (a) Lysosomes are single membrane bound vesicular organelles rich in acid hydrolases.

They are involved in phagocytosis.

44. Genes located on mitochondrial DNA [1997]

(a) generally show maternal inheritance

(b) are always inherited from the male parent

(c) show biparental inheritance like the nuclear genes

(d) are not inherited Solution: (a) Genes located on the mitochondrial DNA are inherited through the cytoplasm. The

zygote receives cytoplasm from the female

gamete hence it involves maternal inheritance.

45. Some of the enzymes,which are

associated in converting fats into carbhoydrates, are present in [1999]

(a) liposomes

(b) golgi bodies (c) microsomes

(d) glyoxysomes Solution: (d) Golgi bodies are cytoplasmic organelle which take part in elaboration and

secretion of complex biochemicals. Microsomes are small single membraned

cell organelles that absorb oxygen and

perform direct oxidation of substrates. Glyoxisomes contain enzymes for b-

oxidation of fatty acids.



46. Which of the following organ has single membrane? [1999]

(a) Nucleus (b) Cell Wall

(c) Mitochondria (d) Spherosomes

Solution: (d) Nucleus is enclosed by a double layered

envelope. Sphaerosomes are small

spherical single membrane bound cell organelles specialized to synthesize and

store fat. Mitochondria is also surrounded by a two layered membrane - outer

membrane and inner membrane.

47. The proteins are synthesised at

[1999] (a) ribosomes

(b) mitochondria (c) centrosomes

(d) golgi bodies Solution: (a) Ribosomes are the sites of protein synthesis mitochondria is the site of ATP

synthesis. Golgi complex takes part in

elaboration and secretion of complex biochemicalls. The distinctly staining

region of cytoplasm surrounding the pair of centrioles together with the centrioles is

called centrosome.

48. The cell organelle involved in glyco-sylation of protein is [2000]

(a) ribosome

(b) peroxisome (c) endoplasmic reticulum

(d) mitochondria Solution: (c) Glycosylation is the process or result of addition of saccharides to proteins and

lipids. The process is one of four principal

co-translational and posttranslational modification steps in the synthesis of

membrane and secreted proteins and the majority of proteins synthesized in the

rough ER undergo glycosylation. It is an enzyme-directed site-specific process, as

opposed to the non-enzymatic chemical reaction of glycation.

49. Microtubules absent in [2001] (a) mitochondria

(b) centriole

(c) flagella

(d) spindle fibres Solution: (a) Microtubules are formed of dimers of tubulin. Microtubules are present in

centriole, flagella, spindle fibres but not in Mitochondria.

50. Element necessary for middle

lamella is [2001]

(a) Ca (b) Zn

(c) K (d) Cu

Solution: (a) Zinc is an activator of enzymes like

carbonic anhydrase. Copper takes part in

electron transport as plastocyanin. Potassium maintains membrane

permeability.

51. In fluid mosaic model of plasma membrane [2002]

(a) upper layer is non-polar and hydrophilic (b) upper layer is polar and hydrophobic

(c) phospholipids form a bimolecular layer

in middle part (d) proteins form a middle layer

Solution: (c) Fluid mosaic model of plasma membrane

proposes that plasma membrane comprises of a phospholipid bilayer wherein icebergs

of proteins floating in sea of phospholipids.

52. Which of the following occurs more

than one and less than five in a chromosome? [2002]

(a) Chromatid (b) Chromosome

(c) Centromere (d) Telomere

Solution: (a) A chromatid is one of two identical strands of DNA making up a chromosome that are

joined at their centromeres, for the process of nuclear division (mitosis or meiosis). The

term is used so long as the centromeres remain in contact. When they separate

(during anaphase of mitosis and anaphase 2 of meiosis), the strands are called

daughterchromosomes.The tips of the

chromatid are called telomeres.They are there to prevent the ends of the

chromosome from attaching to other


chromosomes. It has been said that after

repeated cell replication, the telomeres gets shorter resulting in cell death. Thus, this

mean that the way telomeres work could play a role in determining the lifespan of a

cell.

53. Ribosomes are produced in [2002] (a) nucleolus

(b) cytoplasm

(c) mitochondria (d) golgi body

Solution: (a) Golgi bodies take part in elaboration and

secretion of complex biochemicals. Mitochondria are the site of ATP synthesis.

Ribosomes are produced in nucleolus.

54. Mitotic spindle is mainly composed

of which protein? [2002] (a) Actin

(b) Myosin (c) Tubulin

(d) Myoglobin Solution: (c) Mitotic spindles are composed of

microtubules which are made of tubulin dimers. Actin and myosin are the

contractile proteins of muscle fibres. Myoglobin is oxygen carrying pigment

found in muscle.

55. In which one of the following is nitrogen not a constituent? [2003]

(a) Pepsin

(b) Idioblast (c) Bacteriochlorophyll

(d) Invertase Solution: (b) Raphides are needle-shaped crystals of calcium carbonate or calcium oxalate found

in specialized plant cells called idioblasts. It

is believed that the raphides are a defense mechanism against plant predators, as

they are likely to tear the soft tissues of the throat or esophagus of a plant predator

chewing on the plant‘s leaves. They are non-nitrogenous substances.

56. Flagella of prokaryotic and

eukaryotic cells differ in [2004]

(a) type of movement and placement in cell (b) location in cell and mode of functioning

(c) microtubular organization and type of

movement (d) microtubular organization and function

Solution: (c) Prokaryotes have simple flagella without

microtubules whereas eukaryotes have complex cilia and flagella which consists of

microtubules arranged in 9+2 fashion (an outer ring of nine pairs surrounding 1

center pair). Further in prokaryotes the

arrangement is 9+0.

57. In chloroplasts, chlorophyll is present in the [2004]

(a) outer membrane (b) inner membrane

(c) thylakoids

(d) stroma Solution: (c) The thylakoid membranes possess the chlorophylls. The outer membrane is

permeable to a number of solutes. Inner membrane has a number of carrier

proteins. Stroma forms the matrix containing the enzyme for Calvin cycle.

58. The main organelle involved in modification and routing of newly

synthesized proteins to their destinations is [2005]

(a) chloroplast (b) mitochondria

(c) lysosome (d) endoplasmic Reticulum

Solution: (d) Endoplasmic reticulum transport proteins and enzymes to their destinations i.e.

within the cell and outside the cell.

59. 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? [2005]

(a) Proteins in cell membranes can travel within the lipid bilayer.

(b) Proteins can also undergo flip-flop movements in the lipid bilayer.

(c) Proteins can remain confined within

certain domains of the membrane. (d) Many proteins remain completely

embedded within the lipid bilayer.


Solution: (b) Flip-Flop movement is due to migration of lipid molecules from one lipid monolayer to

other monolayer of lipid bilayer.

60. A student wishes to study the cell structure under a light microscope

having 10X eyepice and 45X objective. He should illuminate the object by which

one of the following colours of light so

as to get the best possible resolution? [2005]

(a) Blue (b) Green

(c) Yellow (d) Red

Solution: (a) Resolving power or limit of resolution is the ability of the eye to distinguish two

close objects as separate. Its value is calculated by Abbe‘s equation,

61. Centromere is required for: [2005]

(a) movement of chromosomes towards poles

(b) cytoplasmic cleavage

(c) crossing over (d) transcription

Solution: (a) During anaphase APC (anaphase

promoting complex) develops. It degenerates proteins binding the two

chromatids in the region of centromere. As a result the centromere of each

chromosome divides. This converts the two

chromatids into daughter chromosomes.

62. Protein synthesis in an animal cell occurs [2005]

(a) only on the ribosomes present in cytosol (b) only on ribosomes attached to the

nuclear envelope and endoplasmic

reticulum (c) on-ribosomes present in the nucleolus

as well as in cytoplasm (d) on ribosomes present in cytoplasm as

well as in mitochondria Solution: (d) Protein synthesis in an animal cell occurs on ribosomes present in cytoplasm as well

as in mitcohondria because mitochondria

and chloroplast also have their own DNA, RNA and ribosome so can synthesize half of

their required proteins.

63. Which of the following statement regarding mitochondrial membrane is

not correct? [2006] (a) The enzymes of the electron transfer

chain are embedded in the outer membrane (b) The inner membrane is highly

convoluted forming a series of infoldings (c) The outer membrane resembles a sieve

(d) The outer membrane is permeable to all

kinds of molecules Solution: (a) The enzymes of electron transport system are present in inner mitochondrial

membrane.

64. A major break through in the studies

of cells came with the development of electron microscope. This is because

[2006] (a) the resolving power of the electron

microscope is 200 – 350 nm as compared to 0.1 – 0.2 for the light microscope

(b) electron beam can pass through thick materials, whereas light microscopy

requires thin sections

(c) the electron microscope is more powerful than the light microscope as it

uses a beam of electrons which has wavelength much longer than that of

photons (d) the resolution power of the electron

microscope in much higher than that of the light microscope

Solution: (d) A major break through in cell studies came with the development of EM having great

resolution power due to which we can see the ultrastructures of cell organelles.

65. Select the wrong statement from the

following [2007]

(a) Both chloroplasts and mitochondria have an internal compartment, the

thylakoid space bounded by the thylakoid membrane

(b) Both chloroplasts and mitochondria contain DNA

(c) The chloroplasts are generally much large than mitochondria

(d) Both chloroplasts and mitochondria

contain an inner and an outer membrane. Solution: (a)


Both chloroplasts and mitochoridria have

an internal compartment, the thylakoid space bounded by double membrane

66. Which one of the following is not a

constituent of cell membrane? [2007] (a) glycolipids

(b) proline (c) phospholipids

(d) cholesterol.

Solution: (b)

67. Keeping in view the fluid mosaic

model for the structure of cell membrane, which one of the following

statements is correct with respect to the

movement of lipids and proteins from one lipid monolayer to the other

(described as flipflop movement)? (a) Both lipids and proteins can flip-flop

(b) While lipids can rarely flip-flop, protein can not

(c) While proteins can flip-flop, lipids can not

(d) Neither lipids, nor proteins can flip-flop

Solution: (b) Keeping in view the ‗Fluid mosaic model‖

for the structure of cell membrane, the movement of lipids and proteins from one

lipid monolayer to the other, lipid can rarely flip-flop, protein can not. The fluid

mosaic model is the most important and widely accepted latest model for plasma

membrane was given by Singer and

Nicolson in 1972. According the them it is ― protein iceberg in a sea of lipids‖.

68. Polysome is formed by

(a) several ribosomes attached to a single mRNA

(b) many ribosomes attached to a strand of

endoplasmic reticulum (c) a ribosome with several subunits

(d) ribosomes attached to each other in a linear arrangement

Solution: (a) Polysome (Polyribosome) is a complex

formed by several ribosomes attached to a single mRNA molecule in the process of

translation.

69. Cellulose is the major component of

cell walls of [2008]

(a) Pythium

(b) Xanthomonas (c) Pseudomonas

(d) Saccharomyces Solution: (a) Cellulose is a major component of cell wall of Pythium. Pythium is a genus of parasitic

Oomycete. Because this group of organisms were once classified as fungi, they are

sometimes still treated as such. Pythium,

like others in the family Pythiaceae, are usually characterized by their production of

coenocytic hyphae, hyphae without separations. Oogonia generally contain a

single Oospore. Antheridia contain an elongated and club shaped antheridium.

70. The two sub-units of ribosome remain united a critical ion level of

[2008] (a) copper

(b) manganese (c) magnesium

(d) calcium

Solution: (c) The two subunits of ribosome remain

united at a critical ion level of magnesium. The presence of magnesium and its amount

plays an important role in the appearance and structure of the ribosomes. If

magnesium is absent in medium, the large particles fall apart to present a group of

smaller particles.

71. Vacuole in a plant cell [2008]

(a) is membrane-bound and contains storage proteins and lipids

(b) is membrane-bound and contains water and excretory substances

(c) lacks membrane and contains air (d) lacks membrane and contains water

and excretory substances

Solution: (b) Vacuole in a plant cell is membrane bound

and contains water and excretory substance. Vacuole is a space within the

cytoplasm of living cell that is filled with



air, water or other liquid, cell sap or food

particles. In plant cells, there is usually one large vacuole bounded by a single layered

membrane (tonoplast or vacuole membrane); animal cells usually have

several small vacuoles.

72. Plasmodesmata are: [2009] (a) locomotary structures

(b) membranes connecting the nucleus with

plasmalemma (c) connections between adjacent cells

(d) lignified cemented layers between cells Solution: (c) Plasmodesmata are connections between adjacent cells. Plasmodesmata are narrow

channels that act as intercellular

cytoplasmic bridges to facilitate communication and transport of materials

between plant cells. Plasmodesmata are formed during cell division, when traces of

the endoplasmic reticulum become caught in the new wall that divides the parent cell.

73. Cytoskeleton is made up of: [2009]

(a) callose deposits

(b) cellulosic microfibrils (c) proteinaceous filaments

(d) calcium carbonate granules Solution: (c) The cytoskeleton is made up of three kinds of protein filaments actin filaments (also

called microfilaments), intermediate filaments and microtubules whose major

constituents are actin and tubulin

respectively.

74. Stroma in the chloroplasts of higher plant contains: [2009]

(a) light-dependent reaction enzymes (b) ribosomes

(c) chlorophyll.

(d) light– independent reaction enzymes Solution: (d)

Stroma in the chloroplasts of higher plant contains light independent reactions

enzymes. Within the stroma are stacks of thylakoids, the sub-organelles which are

the site of photosynthesis.

75. Middle lamella is composed mainly

of: [2009] (a) muramic acid

(b) calcium pectate

(c) phosphoglycerides

(d) hemicellulose Solution: (b) Middle lamella is mainly composed of calcium pectate. Calcium is deposited in

plants cell walls during their formation - it is required for the stability and function of

cell membranes and acts as a type of ‗cementing agent‘ in the cell walls in the

form of calcium pectate‘. Calcium pectate is

like a glue binding adjacent cells together so if inadequate calcium is not transported

during cell formation, tissues become less stable and prone to disintegration.

76. Which one of the following

structures between two adjacent cells is

an effective transport pathway? [2010] (a) Plasmodesmata

(b) Plastoquinones (c) Endoplasmic reticulum

(d) Plasmalemma Solution: (a) Plasmodesmata are the structure between two adjacent cells that permits the

transport and communication between

them. They are the fine cytoplasmic strands that connect the protoplasts of adjacent

plant cells by passing through the cell walls.

77. Which one of the following has its

own DNA? [2010] (a) Mitochondria

(b) Dictyosome

(c) Lysosome (d) Peroxisome

Solution: (a) Mitochondria has its own DNA. It is as

structure within cytoplasm of eukaryotic cells that carries out aerobic respiration. It

is the site of Kreb‘s cycle and ETS.

Therefore, it is also called as cell‘s energy production site.

78. The main arena of various types of

activities of a cell is: [2010] (a) plasma membrane

(b) mitochondrian (c) cytoplasm

(d) nucleus

Solution: (c) The main arena of various types of

activities of a cell is cytoplasm. It forms the


living protoplasm of a cell excluding the

nucleus. It consists of proteins, fats, carbohydrates, nucleic acids, vitamins,

waste metabolites and all organelles.

79. The plasma membrane consists mainly of: [2010]

(a) phospholipids embedded in a protein bilayer

(b) proteins embedded in a phospholipid

bilayer (c) proteins embedded in a polymer of

glucose molecules (d) proteins embedded in a carbohydrate

bilayer Solution: (b) Plasma membrane comprises mainly

proteins embedded in a phospholipid bilayer. Protein molecules occur at places

both inside and outer side of the lipid bilayer.

80. Given below is a sample of a portion

of DNA strand. What is so special shown in it? 5‘ —— GAATTC —— 3‘ 3‘ ——

CTTAAG —— 5‘ [2011]

(a) Replication completed (b) Deletion mutation

(c) Start codon at the 5‘ end (d) Palindromic sequence of base pairs

Solution: (d) The sample of a portion of DNA strand

shown in the figure is palindromic sequence of base pairs.

81. Important site for formation of glycoproteins and glycolipids is [2011]

(a) vacuole (b) golgi apparatus

(c) plastid (d) lysosome

Solution: (b) Golgi apparatus is the important site for formation of glycoprotein and glycolipid.

82. Peptide synthesis inside a cell takes

place in: [2011] (a) chloroplast

(b) mitochondria (c) chromoplast

(d) ribosomes

Solution: (d) Peptide synthesis takes place in ribosome

inside a cell.

83. What are those structures that appear as beads - on- string in the

chromosomes when viewed under electron microscope? [2011]

(a) Genes (b) Nucleotides

(c) Nucleosomes (d) Base pairs

Solution: (c) Under electron microscope the nucleosomes appear as beads on string in

chromosome, due to a short length of DNA wrapped around a core of histone proteins.

84. The Golgi complex plays a major role

[NEET 2013]

(a) in digesting proteins and carbohydrates (b) as energy transferring organelles

(c) in post translational modification of proteins and glycosidation of lipids

(d) in trapping the light and transforming it into chemical energy

Solution: (c) Golgi apparatus plays a major role in post

translational modification of proteins

forming glycoprotein and glycosidation of lipid forming glycolipids. A number of

proteins and lipids synthesised on endoplasmic reticulum (rough and smooth

respectively) are modified in the cisternae of the Golgi apparatus before they are

released from it trans face.

85. In mitochondria, proteins

accumulate in the [2011M] (a) outer membrane

(b) inner membrane (c) intermembrane space

(d) matrix Solution: (b) The inner membrane of mitochondria

contains more than 151 different polypeptides, and has a very high protein-

to- phospholipid ration.

86. Which one of the following is not considered as a part of the

endomembrane system? [2011M] (a) Golgi complex

(b) Peroxisome

(c) Vacuole (d) Lysosome

Solution: (b)


Except peroxisome the remaining three

and ER are the parts of endomembrane system.

87. Ribosomal RNA is actively

synthesized in [2012] (a) Lysosomes

(b) Nucleolus (c) Nucleoplasm

(d) Ribosomes

Solution: (b) Ribosomal RNA is actively synthesized in

nucleolus. Nucleolus is also known as ribosomal factory.

88. Which one of the following does not

differ in E.coli and Chlamydomonas

[2012] (a) Ribosomes

(b) Chromosomal Organization (c) Cell wall

(d) Cellmembrane Solution: (d) Cell membrane of E.coli, a bacteria and Chlamydomonas a unicellular green alga

does not differ. As in both cell membrane is

composed of lipids and proteins.

89. What is true about ribosomes [2012] (a) The prokaryotic ribosomes are 80S,

where ―S‖ stands for sedimentation coefficient

(b) These are composed of ribonucleic acid and proteins

(c) These are found only in eukaryotic cells

(d) These are self-splicing introns of some RNAs.

Solution: (b) Ribosomes are amembraneous (ie. without

membrane) cell organelle composed of rRNA and protein. These are found in both

prokaryotic and eukaryotic cells. In

prokaryotes, ribosomes are 70S type while in eukaryotes, it is 80S type.

90. Nuclear mebrane is absent in [2012]

(a) Penicillium (b) Agaricus

(c) Volvox

(d) Nostoc Solution: (d)

Nostoc is prokaryote while rest are

eukaryotes. Nuclear membrane is absent in prokaryotes.

91. Select the correct statement from

the following regarding cell membrane. [2012]

(a) Na+ and K+ ions move across cell membrane by passive transport

(b) Proteins make up 60 to 70% of the cell

membrane. (c) Lipids are arranged in a bilayer with

polar heads towards the inner part. (d) Fluid mosaic model of cell membrane

was proposed by Singer and Nicolson Solution: (d) Fluid mosaic membrane model was

proposed by Singer and Nicholson in 1972. It is most accepted model of structure of

biomembrane.

92. Which one of the following structures is an organelle within an

organelle? [2012M] (a) Ribosome

(b) Peroxisome

(c) ER (d) Mesosome

Solution: (a) Ribosome are small naked (non membrane

bound) particles made of r-RNA and proteins. Ribosomes are also seen in the

organelles like mitochondria and chloroplasts. They are the cell‘s protein

factories and are found on RER and

scattered in the cytoplasm as polyribosomes. Ribosomes are the sites at

which information carried in the genetic code is converted into protein molecules.

93. Which one of the following cellular

parts is correctly described? [2012M]

(a) Centrioles - Sites for active RNA synthesis.

(b) Lysosomes - Optimally active at a pH of about 8.5.

(c) Thylakoids - Flattened membranous sacs forming the grana of chloroplasts.

(d) Ribosomes - Those on chloroplasts are larger (80s) while those in the cytoplasm

are smaller (70s).

Solution: (c) Centrioles serve as basal bodies for cilia

and flagella. They are concerned with


spindle formation during cell division.

Lysosomes are membrane-bound organelles containing many hydrolytic enzymes, which

are optimally active at an acid pH (near pH 5). Thylakoids are membrane-bound

organelles found within chloroplasts. The thylakoid membrane, forms many flattened,

fluid-filled tubules that enclose a single convoluted compartment. These tubules

tend to stack on top of each other to forma

structure called a granum.

94. Stroma in the chloroplasts of higher plant contains: [2009]

(a) light-dependent reaction enzymes (b) ribosomes

(c) chlorophyll.

(d) light– independent reaction enzymes Solution: (d) Stroma in the chloroplasts of higher plant contains light independent reactions

enzymes. Within the stroma are stacks of thylakoids, the sub-organelles which are

the site of photosynthesis.

95. The Golgi complex plays a major role

[NEET 2013] (a) in digesting proteins and carbohydrates

(b) as energy transferring organelles (c) in post translational modification of

proteins and glycosidation of lipids (d) in trapping the light and transforming it

into chemical energy Solution: (c) Golgi apparatus plays a major role in post

translational modification of proteins forming glycoprotein and glycosidation of

lipid forming glycolipids. A number of proteins and lipids synthesised on

endoplasmic reticulum (rough and smooth respectively) are modified in the cisternae of

the Golgi apparatus before they are

released from it trans face.

96. A major site for synthesis of lipids is: [NEET 2013]

(a) SER (b) Symplast

(c) Nucleoplasm (d) RER

Solution: (a) The smooth endoplasmic reticulum is the major site for synthesis of lipid. In animal

cells lipid like steroidal hormones are

synthesised in SER.

97. The term ‗glycocalyx‘ is used for [NEET Kar. 2013]

(a) A layer surrounding the cell wall of bacteria

(b) A layer present between cell wall and membrane of bacteria

(c) Cell wall of bacteria

(d) Bacterial cell glyco-engineered to possess N-glycosylated proteins

Solution: (a) Glycocalyx or mucilage is the outermost

coating of bacterial cells/cell wall which is rich in polysaccharides. A thick and

tougher mucilage is called capsule which

gives gummy or sticky trait to cells. It protects the cells from dessication, toxins

and preventing attachment to foreign invaders.

98. Which of the following type of

plastids does not contain stored food material? [NEET Kar. 2013]

(a) Amyloplasts

(b) Chromoplasts (c) Elaioplasts

(d) Aleuroplasts Solution: (b) Chromoplasts are non-photosynthetic coloured plastides which synthesise and

stored carotenoid pigmentes. They, therefore, appear orange red and yellow

where as amyloplast (store starch),

aleuroplast (store proteins) and elaioplast (store oil droplets and fats) are leucoplasts,

colourless plastids.

99. The basic unit of nucleic acid is [1991]

(a) Pentose sugar

(b) Nucleoid (c) Nucleoside

(d) Nucleotide Solution: (d) Nucleic acid (DNA and RNA) comprises of polynucleotides. Each nucleotide consist of

nitrogenous bases, pentose sugar and phosphoric acid.

100. Why is a capsule advantageous to a bacterium? [NEET Kar. 2013]


(a) It allows the bacterium to attach to the

surface (b) It protects the bacterium from

desiccation (c) It provides means of locomotion

(d) It allows bacterium to ―hide‖ from host‘s immune system

Solution: (d) Capsule is a layer that lies outside the cell

wall of bacteria. The capsule can protect

cells from engulfment by eukaryotic cells, such as macrophages. They also exclude

bacterial viruses and most hydrophobic toxic materials such as detergents.

96 Topicwise Solved Previous Year Qs Cell: The Unit of Life intracellular digestion of...

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