Monday, 22 August 2016


The cell is the basic unit of structure and function in any organism. It is a unit quantity of living substance that is protoplasm bounded a unit membrane. The structure and functioning of all cells together reflect on the existence or well-being of the entire organism.

Now read the following questions and answers and suggest some more questions for the aspirants for competitive exams. Please help us rectify the mistakes and improve the content.


1) What is the structural and functional unit of all organisms?
A) Cell
2) When did living cells originate on the Earth?
A) 3.5 billion years ago.
3) What is the smallest unit of life?
A) Cell
4) What are the building blocks of life?
A) Cells
5) Which branch of science deals with the study of cells?
A) Cytology
6) Which branch of science deals with the study of all aspecys of cells?
A) Cell biology
7) Who discovered cell?
A) Robert Hooke
8) Who coined the term cell?
A) Robert Hooke
9) With what Robert Hooke compared the cells in the cork?
A) With cells in the Christian monastery
10) Who discovered living cells?
A) Anton Van Leeuenhoek
11) Who discovered bacteria and protozoa?
A) Anton Van Leeuenhoek
12) Who coined the term cell wall?
A) Robert Hooke
13) What was the famous book written by Robert Hooke?
A) Micrographia
14) Who gave the first idea of cell theory?
A) Dutrochet
15) Who gave the cell theory for plants?
A) MJ Schleiden
16) Who gave the cell theory for animals?
A) Theodore Schwann
17) Who gave the cell theory?
A) Schleiden & Schwann
18) Who gave the cell lineage theory?
A) Rudolf Virchow
19) What is the famous phrase of Rudolf Virchow?
A) Omnis cellula e cellulae (all cells are formed from pre-existing cells)
20) Which discovery was a proof to Virchow's cell lineage theory?
A) Mitosis
21) Name some organisms which are exception to the cell theory?
A) Viruses, Paramecium, Rhizopus, Vaucheria
22) Who proposed organism theory?
A) Sachs
24) What are the mammalian cells without respiration and replication?
25) What are the mammalian cells without a nucleus?
26) What are the plant cells without nucleus?
A) Sieve Tubes
27) Why the RBCs cannot replicate?
A) Nucleus or DNA is absent
28) Why the RBCs cannot respire?
A) Absence of mitochondria
29) What are the nucleated animal cells which cannot differentiate?
A) Nerve cells
30) What is the ability of a cell to reproduce to a complete organism?
A) Totipotency
31) Who induced morphogenesis in plant callus for the first time?
A) Skoog & Miller
32) Who established the concept of cellular totipotency?
A) Steward et al.
33) What are the energy transducers in plant cells?
A) Chloroplasts
34) Why are the smaller cells metabolically efficient?
A) Higher nucleo-plasmic ratio & surface volume ratio
35) What would happen to the surface volume ratio if the size of a cell is doubled?
A) Surface volume ratio decreases by half
36) What is the chief function of microvilli?
A) to increase surface area for absorption
37) What is a rod shaped bacterium?
A)  Bacillus
38) What is a spherical shaped bacterium?
A)  Coccos
39) What is a comma shaped bacterium?
A)  Vibrium
40) What is a spiral shaped bacterium?
A)  Spirillum
41) Name the prokaryote whose shape keeps on changing?
A) Mycoplasma
42) Name the protozoan whose shape keeps on changing?
A) Amoeba
43) What are the amoeboid cells in the human body?
A) Leucocytes  (WBCs)
44) Which is the largest unicellular organism?
A) Acetabularia (marine alga)
45) Which is the umbrella shaped unicellular alga?
A) Acetabularia
46) Which is the longest cell?
A) Fibre cell of Boehmeria nivea (Ramie)
47) Which is the longest animal  cell?
A) Nerve cell
48)Which is the smallest cell?
A) PPLO (Pleuro Pneumonia Like Organisms)
49)Which is the largest cell?
A) Ostrich egg
50) Who coined the terms prokaryotic and eukaryotic cells?
A) Dougherty
51) What are the organisms with an indistinct diffused nucleus?
A) Prokaryotes
52) What are the organisms with a distinct nucleus?
A) Eukaryotes
53) Which is the prokaryotic organism without a cell wall?
A) Mycoplasma
54) Which is the smallest prokaryotic cell?
A) PPLO (Pleuro Pneumonia Like Organisms)
55) Where is a double stranded circular naked DNA present?
A) Prokaryotes,  mitochondria & plastids  (chloroplasts)
57) What are the organisms without membranous organelles?
A) Prokaryotes
58) What are the cells within cells?
A) Mitochondria and chloroplasts
59) What are the organelles within organelles?
A) Ribosomes in mitochondria and chloroplasts
60) Where are 70S ribosomes present?
A) Prokaryotes,  mitochondria and plastids  (chloroplasts)
61) What are cyanobacteria? A) Blue-green algae
62) What are the units of golgi apparatus in plant cells?
A) Dictyosomes
63) What kind of microbodies are absent in animal cells?
A) Glyoxysomes
64) What is the outermost layer of animal cells?
A) Cell membrane
65) What is the outermost layer of plant  cells?
A) Cell wall
66) What is the biggest organelle in animal cells?
A) Nucleus
67) What is the biggest organelle in mature plant  cells?
A) Vacuole
68) Why are animal cells heterotrophic?
A) Due to absence of chloroplasts
69) Why are plant cells autotrophic?
A) Due to presence of chloroplasts
70) What kind of cells possess centrioles?
A) Animal cells
71) Why do animal cells burst when they are kept in hypotonic solution?
A) Due to lack of cell walls
72) Which is the unit of measurement in light microscopes?
A) Micron
73) What is the unit of measurement in electron microscopes?
A) Angstrom
74) What are the organisms that can be seen only under electron microscope?
A) Viruses and PPLOs or mycoplasmas
75) What are the cell structures that can be seen under light microscope?
A) Cell wall, nucleus,  chloroplasts and mitochondria
76) What are the cell structures that can be seen under electron microscope only?
A) Ribosomes,  endoplasmic reticulum,  cell membrane, lysosomes,  microbodies, etc
77) What are the jokers of the plant kingdom?
A) Mycoplasmas
78) In what kind of organisms the respiratory enzymes areassociated with cell membranes?
A) Prokaryotes
79) What are the structures in bacterial cells comparable with mitochondria?
A) Mesosomes
80) What is the primitive nucleus of prokaryotes?
A) Chromomere, genophore, incipient nucleus or nucleoid
81) What type of cell division is common among prokaryotic cells?
A) Amitosis
82) What type of cell divisions are common among eukaryotic cells?
A) Mitosis & meiosis
83) What kind of cells have 80S ribosomes?
A) Eukaryoticcells
84) How many cells a human body has?
A) more than 10 trillion cells
85) What were the first living forms on the Earth?
A) Prokaryotes
86) What are the extra-chromosomal DNA elements in bacteria?
A) Plasmids
87) Where are antibiotic resistance genes located in bacteria?
A) On plasmids
88) What is the main distinguishing feature of eukaryotes as compared to prokaryotes?
A)  Compartmentalization (organelles)
89) What is the main organizer and maintainer of the eukaryotic cell's shape?
A) Cytoskeleton
90) What are parts of the cell which are specialized for different vital functions?
A) Organelles
91) What are the solitary cell organelles in a typical cell?
A) Nucleus & Golgi apparatus
92) What are the liquid filled spaces surrounded by a membrane?
A) Vacuoles
93) Who described single celled organisms as animalcules?
A) Anton van Leeuwenhoek
94) Who first observed muscle fibres, spermatozoa and blood cells under microscope?
A) Anton van Leeuwenhoek
95) Who invented the first compound microscope?
A) Zacharias Jansen
96) Who designed the first electron microscope?
A) Max Knoll & Ernst August Friedrich Ruska
97) Who discovered nucleus?
A) Robert Brown
98) Who discovered cytoplasmic streaming?
A) Robert Brown
99) Who discovered mitochondria?
A) Richard Altmann
100) How did Altmann call mitochondria?
A) Bioblasts
101) Who coined the term "mitochondria?
A) Carl Benda
102) Who discovered Janus green as supra vital stain for mitochondria?
A) Leonor Michaelis
103) Who discovered chloroplasts?
A) Julius von Sachs
104) Who discovered  9 + 2 microtubule structure in cilia?
A) Keith Roberts Porter
105) Who coined the term endoplasmic reticulum?
A) Keith Roberts Porter
106) Who discovered peroxisome and lysosome?
A) Christian René Marie Joseph Viscount de Duve
107) Who is considered "the most influential cell biologist ever"
A) Palade
108) Who discovered ribosomes on endoplasmic reticulum?
A) Palade
109) Who discovered double helical model of DNA?
A) Watson & Crick
110) Who discovered the chromosomal movements in mitosis?
A) Flemming
111) Who described sarcosomes and later they come to be known as the mitochondria?
A) Albert von Kölliker
112) What is the study of nucleus?
A) Karyology
113) What are the most primitive forms of life on the Earth?
A) Prokaryotes
114) What kind of other cells form about 95% of all the cells in the human body?
A) Bacteria
115) What is the term used to describe the suicide committed by cells?
A) Apoptosis
116) What are the human cells with longest life span?
A) Neurons
117) What is the smallest objects that the unaided human eye can see?
A) About 0.1 mm long
118) What is the maximum possible power of a light microscope as it is limited by the wavelength of visible light?
A) 500 nm
119) What is required to see anything smaller than 500 nm?
A) Electron microscope
120) What is the size of most bacterial cells?
A) 0.2 to 10 microns
121) What is the size of Amoeba proteus?
A) 250 to 750 microns
122) What is the size of most animal cells?
A)10 to 100 microns
123) What is the diameter of an RBC?
A) 8 microns
124) What is the length of a giraffe's nerve cell?
A) 2 meters (about 6 feet)
125) What is the length of an ostrich egg cell?
A) 6 inches (half foot)
126) What is the size of a human egg cell?
A) 100 microns
127) What is the size of a ramie fibre, longest cells in the plant kingdom?
A) 13 to 15 cm (5 to 6 inches)
128) What is the instrument used to see objects that are too small for the naked eye?
A) Microscope
129) Which is the most common microscope?
A)  Optical microscope or light microscope
130) What was the first microscope to be developed?
A)  Optical microscope or light microscope
131) Who coined the term microscope for Galileo Galilei's compound microscope?
A) Giovanni Faber
132) What are the branches of microscopy?
A) Optical, electron, and scanning probe microscopy
133) What are the microscopes functioning on visible light?
A) Optical or light microscopes
134) Which is the most advanced light  microscope? A) Digital microscope & Fluorescents microscope
135) Which is the simplest of all the light microscopy techniques?
A) Bright field microscopy
136) How could we get the 3-dimensional image in a light microscope?
A) By oblique illumination
137) What is the technique for improving the contrast of unstained, transparent specimens?
A) Dark field microscopy
138) What is the optical technique that results in a coloured image of a colourless object?
A) Dispersion staining
139) What is the microscopic technique to show differences in refractive index?
A) Phase contrast
140) Who invented the phrase contrast microscope?
A) Frits Zernike
141) Who invented the first electron microscope or the transmission electron microscope (TEM)?
A) Ernst Ruska
142) What is used in the place of light in electron microscope?
A) Electrons
143) In what kind of microscopes photons are used?
A) Optical or light microscopes
144) What is used instead of lenses in electron microscope?
A) Electromagnets
145) Who invented the scanning electron microscope?
A) Max Knoll
146) Who invented the first scanning probe tunnelling  microscopes?
A) Gerd Binnig and Heinrich Rohrer
147) Who invented the atomic force microscope?
A) Gerbe
148) What is the magnifocation  limit of a light microscope?
A) up to 1250 X
149) What is the resolution limit of a light microscope?
A)  0.250 micrometres or 250 nanometres
150) What is the magnification of the simplest optical microscope (magnifying glass)?
A)  10X magnification
151) Which lens is at the top of a compound microscope to look through?
A) Eyepiece Lens
152) What is the general illuminator in a compound microscope?
A) Mirror or 100 volts light source
153) Which part of the microscope holds two or more objective lenses and can be rotated to easily change power?
A) Revolving Nosepiece or Turret
154) Which lens is kept near the object to see in the compound microscope?
A) Objective lens
155) What is the magnification power of objective lenses in a compound micriscope?
A) 4X, 10X, 40X and 100X
156) What is the rotating disc to vary intensity and size of the cone of light at the base of the stage?
A) Diaphragm
157) What are the components of the Gram stain used for bacteria?
A) Crystal violet, iodine and fuchsin or safranin
158)Which stain is used to mark bacterial cell walls?
A) Crystal violet
159)Which dye is used to stain cells of Mycobacterium tuberculosis?
A) Ziehl-Neelsen stain
160) Which dye stains the cell nucleus blue?
A) Haematoxylin
161) Which dye stains cytoplasm and RBC pink or bright red?
A) Eosin
162) Which dye is used to mark carbohydrates (glycogen, glycoprotein, proteoglycans)?
A) Periodic acid- Schiff staining
163) Which dye is a nucleic acid selective fluorescent cationic dye useful for cell cycle determination?
A) Acridine orange
164) What is used as an indicator for starch?
A) Iodine
165) Which dye is used to stain animal cells, such as human cheek cells, to make their nuclei more observable?
A) Methylene blue
166) Which is a red cationic dye that binds to nuclei (DNA),  cartilage, mast cells, lignin and plastids?
A) Safranine O
167) Which stain is used in optical microscopy to stain lipids?
A) Osmium tetroxide
168) From which part of Haematoxylum tree hematozylin dye is extracted?
A) Heartwood
169) Which is the common stain to observe mitochondria through a microscope?
A) Janus Green B
170) Which stain was used by Altmann to observe mitochondria?
A) Acid fuchsine
171) Which is the common acidophilic dye in microscopic studies?
A) Eosin
172) Which is the common basophilic dye in microscopic studies?
A) Janus Green B
173) What kind of stains are applied on living cells without killing them?
A) Vital stains
174) What are the common vital stains?
A) Eosin, Propidium iodide, Trypan Blue, Erythrosine, Amino actinomycin D,
Janus Green B
175) Which branch of science deals with the study of DNA and RNA?
A) Molecular Biology

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