Cell Ncert Flashcards
1
Q
The Physico-chemical approach to study and understand living organisms, is called
A
Reductionist Biology
2
Q
G.N. Ramachandran is known for?
A
- Discovery of Triple Helix Structure of Collagen (Structural Biology)
- Ramachandran Plot, conformations of proteins
- Influence by Pauling’s models of α-helix and β-sheet structures
(α = Alpha, β = Beta)
3
Q
Cell is __, __ and __ unit of organisms.
A
fundamental; structural; functional
4
Q
Single-celled organisms are called __.
What is its characteristic of it?
A
Characteristics of Unicellular organisms are :
1. Free-living existence present
2. Perform all essential functions
5
Q
Anything less than a Complete cell has not __
A
Living-free existence
6
Q
Exception for the fact “Cell is the fundamental unit of organisms.”
A
Virus due to its Acellular structure
7
Q
Living cell was first described by
A
Anton Von Leeuwenhoek
8
Q
The nucleus was discovered by
A
Robert Brown
9
Q
The structural details of a cell were well-defined after the discovery of __
A
Electron Microscope
10
Q
In __, a German __ who observed that all plants are composed of different kinds of cells which form tissues was__
A
1838; botanist; Matthias Schleiden
11
Q
In __ year, the thin outer layer of animal cells, now known as plasma membrane, was first reported by __ (German Botanist / British Zoologist)
A
1839; Theodore Schwann; British Zoologist
12
Q
Two conclusions of T. Schwann are :
A
The presence of a Cell wall is a unique character of plant cells.
The bodies of animals and plants are composed of cells and products of cells.
13
Q
The scientists who together formulated the cell theory were __ and __.
A
Schleiden and Schwann;
14
Q
In __ year, the scientist who first explained that cells form from pre-existing cells (Omnis cellula-e cellula) was ___
A
1855; Rudolf Virchow
15
Q
Drawback of Cell Theory (proposed by Schleiden and Schwann)
Who modified the hypothesis of Schleiden and Schwann to give a final shape to Cell Theory (Modern Cell Theory)?
A
It didn’t explain How new cells formed;
Rudolf Virchow
16
Q
Cell theory as understood today is:
A
(i) all living organisms are composed of cells and products of cells (given by both Schleiden and Schwann)
(ii) all cells arise from pre-existing cells (Given by Rudolf Virchow)
17
Q
The outer boundary of a typical plant cell is
A
Cell wall
18
Q
Cell membrane is the __ structure of Cell.
A
Delimiting structure of cell
19
Q
Genetic material i.e. DNA-containing chromosomes are located inside a dense structure called
A
Nucleus
20
Q
The cells which possess membrane-bound nuclei are called
A
Eukaryotic
21
Q
Cells which lack membrane-bound nuclei are called
A
Prokaryotic
22
Q
Most of the cell volume is occupied by a semifluid matrix called as
A
Cytoplasm
23
Q
The main arena of cellular/metabolic reactions which keep a cell in a living state is performed in __
A
Cytoplasm
24
Q
The non-membrane-bound organelle found in both prokaryotic and eukaryotic cells is __
A
Ribosomes
25
The organelle which contains ribosomes and is specifically present in plants is __
Chloroplasts
26
Apart from the cytoplasm, organelle containing ribosomes are __
Chloroplasts (in plants), Mitochondria, and rough ER
27
The type of ER possessing ribosomes is __
Rough ER
28
Animal cells contain a non-membrane-bound organelle which helps in cell division, is
Centrosome
29
__ are the smallest living cells and __ in length.
Mycoplasma; 0.3 μm (in length)
30
The largest isolated single cell is __
an egg of Ostrich
31
Cell Size:
Mycoplasma -
PPLO -
Bacteria -
Typical Bacteria -
Virus -
Human RBCs -
Typical Eukaryotic cell -
Mycoplasma - 0.3 μm in length
PPLO - 0.1 μm (in Diameter)
Bacteria - 3-5 μm
Typical Bacteria - 1-2 μm
Virus - 0.02-0.2 μm
Human RBCs - 7 μm (in Diameter)
Typical Eukaryotic cell - 10-20 μm
32
Cell Shape depends on __
Cell functions/activities
33
Cell Shape:
RBCs -
WBCs -
Nerve cell -
Columnar Epithelial Cell -
Mesophyll Cell
Tracheids -
RBCs - Round Biconcave cell
WBCs - Amoeboid
Nerve cell (longest cell) - Branched & Long
Columnar Epithelial Cell - Long & Narrow
Mesophyll Cell - Round & Oval
Tracheids - Elongated
34
The prokaryotic cells are represented by
Bacteria, blue-green algae, mycoplasma
35
PPLO stands for
Pleuro Pneumonia Like Organisms
36
__ cells are generally smaller and multiply more rapidly than the __ cells.
prokaryotic cells; eukaryotic cells
37
Which Bacteria -
Rod-shaped ->
Spherical-shaped ->
Comma-shaped ->
Spiral-shaped ->
Rod-shaped -> Bacillus
Spherical-shaped -> Coccus
Comma-shaped -> Vibrio
Spiral-shaped -> Spirillum
38
A prokaryote which lacks Cell wall is __
Mycoplasma
39
The fluid matrix filling a cell is __
Cytoplasm
40
Naked genetic material without any envelope by nuclear membrane is characteristic of __.
Prokaryotes
41
A small circular DNA outside genomic DNA in bacteria is __
Plasmid DNA
42
A unique phenotypic characters to bacteria are provided by DNA other than genomic DNA is __
Plasmid DNA
43
Example of a unique phenotypic character provided to bacteria by plasmid DNA is __
Resistance to antibiotics
44
The __ confers certain unique phenotypic characters to bacteria
Plasmid DNA
45
__ is used to monitor bacterial transformation with foreign DNA
Plasmid DNA
46
Well organized nucleus with a nuclear membrane is the characteristic feature of __ cells
Eukaryotic
47
__ is the only organelle found in both prokaryotes and eukaryotes
Ribosomes
48
A specialized differentiated form of the cell membrane called __ which prokaryotes have unique in the form of inclusions.
Mesosomes
49
Mesosomes are essential infoldings of __
Cell membrane
50
Most ___ (prokaryotic/eukaryotic) cells, particularly bacterial cells, have a chemically complex cell envelope.
prokaryotic cells
51
Tightly bound three-layered structure of bacterial cell envelop consists of __
Outermost -> Glycocalyx
Middle -> cell wall
Inner -> plasma membrane
52
Each layer of the envelope performs ____ (same/distinct) function, they act together as a _____.
Distinct function; Single protective unit
53
On the Basis of differences in the cell envelopes and Gram staining, bacteria are classified as
Gram-positive and Gram-negative
54
Bacteria taking up gram stain are ___, and the others that do not are called ___ bacteria.
Gram-positive; Gram-negative
55
The layer of cell envelope whose composition and thickness varies to a large extent is __
Glycocalyx
56
The loose sheath of the glycocalyx in bacteria is called
Slime Layer
57
The thick & tough sheath of the glycocalyx in bacteria is called
Capsule
58
What determines the shape of the cell?
Cell Wall
59
____ provides a strong structural support
to a bacterial cell and prevent the bacterium from _____
Cell wall; bursting or collapsing
60
The selectively permeable membrane of a cell that interacts with the outside world, is
plasma membrane
61
The membrane, which is structurally similar to prokaryotes and eukaryotes, is
Plasma membrane
62
A special membraneous structure which is formed by the extensions of plasma membrane into the cell is __
Mesosome
63
The extensions of the cell membrane are in the form of __
Vesicles, tubules and lamellae
64
One major role of mesosomes is __
Helps in
i) Cell wall formation
ii) DNA replication & DNA distribution to daughter cells
iii) Respiration
iv) Secretion processes
v) Increase surface area of plasma membrane and enzymatic content
65
In some prokaryotes like ____, there are other membranous extensions into the cytoplasm called ____ which contain ____.
Cyanobacteria; Chromatophores; pigments
66
Bacterial cells may be ____ (motile/non-motile/both).
Both (motile or non-motile)
67
Motile bacteria have thin filamentous extensions from their cell wall, known as
Flagella
68
All Bacteria show ____ (same/different) number and arrangement of flagella.
different
69
The three main parts of the bacterial flagellum are __
Filament, hook and basal body
70
The longest portion of the bacterial flagellum is ____ and extends from the cell surface to the ____ (inside/outside).
Filament; outside
71
Besides flagella, the two surface structures of Bacteria which do not play a role in motility (locomotion) are __
Pili and Fimbriae
72
The elongated tubular structures composed of a special protein in bacteria are _____
Pili
73
Small bristle-like fibers sprouting out of the bacterial cell are ____
Fimbriae
74
The structure which is known to attach bacteria to rocks in streams or to hosts tissues is ____
Fimbriae
75
In prokaryotes, Ribosomes are associated with the __ of cells.
Plasma membrane
76
The average size of a prokaryotic ribosome is
15 nm by 20 nm
77
The two sub-units of prokaryotic ribosomes are
50S and 30S
78
The 50S and 30S subunits of prokaryotic ribosomes together form __
70S
79
Ribosomes are the site of
Protein synthesis
80
Several ribosomes may attach to mRNA and form a chain, called
Polyribosomes or polysome
81
The ribosomes of a polysome translate the ___ into __.
mRNA into proteins
82
Reserve material in prokaryotic cells is stored in the cytoplasm in the form of
Inclusion bodies
83
Phosphate granule is an example of
Inclusion body
84
Gas vacuoles are the type of __ found in blue-green and purple and green photosynthesis bacteria
Inclusion bbodies
85
Gas vacuoles are found in which bacteria?
Blue-green, purple and green photosynthesis bacteria
86
In eukaryotic cells, there is extensive compartmentalization of cytoplasm through the presence of __
Membrane bound organelles
87
The cells possessing complex locomotory and cytoskeletal structures are __
Eukaryotic cells
88
Eukaryotic cells possess an organized nucleus with __
Nuclear envelope
89
The genetic material of eukaryotes is organized into __
Chromosomes
90
The organelles that are present in plant cells but not in animal cells are __
Plastids
91
The characteristic feature of animal cells is the presence of __
Centrioles
92
The chemical studies on the cell membrane, especially in ___, enabled the scientists to deduce the possible structure of plasma membrane.
Human red blood cells (RBCs)
93
Cell membrane is mainly composed of __
Lipids and Proteins
94
The major lipids in the cell membrane are __
Phospholipids
95
Phospholipids in Cell membrane are arranged in a
Bilayer
96
In a lipid bilayer, the part of lipids that lie towards inside is __
Hydrophobic
97
In addition to phospholipids, membrane also contains __
Cholesterol
98
Apart from cholesterol and lipids, other biomolecules that make up the cell membrane are __
Proteins and carbohydrates
99
The % of proteins in membrane of Human erythrocyte is __
52%
100
The % of lipids in membrane of Human erythrocyte is __
40%
101
Membrane proteins are classified as
Integral and peripheral proteins
102
The proteins that lie on the surface of Membrane are called
Peripheral proteins
103
The proteins that are partially or totally buried in Membrane are called
Integral proteins
104
The fluid mosaic model was proposed by
Singer and Nicolson
105
The fluid mosaic model was proposed in the year __
1972
106
According to the fluid mosaic model, what nature of lipids enables the lateral movement of proteins?
Quasi-fluid nature
107
The quasi-fluid nature of lipids enables which movement of proteins within the bilayer?
Lateral movement
108
The ability of the protein to move within the membrane is measured as its __
Fluidity
109
The fluid nature of the membrane is important for __
Cellular functions
110
Transport of molecules across itself is the most important function of __
Plasma membrane
111
The nature of permeability of plasma membrane is __
Selectively permeable
112
The movement of molecules across the membrane without any requirement of energy is called
Passive transport
113
Neutral molecules move across the membrane by the process of __
Simple diffusion
114
Simple diffusion occurs along the __ gradient
Concentration
115
The movement of water by diffusion is called
Osmosis
116
The type of molecules which require carrier protein to facilitate their transport across the membrane is __
Polar molecules
117
The proteins required by polar molecules to facilitate their transport are called
Carrier proteins
118
During active transport, molecules are transport __ the concentration gradient
against
119
Active transport occurs with the utilization of __
ATP
120
The type of transport during which ATP is utilized is __
Active transport
121
An example of active transport is
Na+/K+ pump
122
The non-living rigid structure forming the outer covering of plasma membrane in fungi and plants is called __
Cell wall
123
The cell wall acts as an outer covering for which membrane?
Plasma membrane
124
___ forms an outer covering for the plasma membrane of fungi and plants.
Cell wall
125
Cell wall protects the cell from __ and __
Mechanical damage and Infection
126
The cell wall provides a barrier to ___
Undesirable macromolecules
127
The Algae cell wall is primarily composed of __
Cellulose, galactans, mannans, and minerals
128
Name a mineral component of the algal cell wall
Calcium Carbonate
129
Plant cell wall is composed of
Cellulose, hemicellulose, pectins and proteins
130
The cell wall of young plants which is capable of growth is __
Primary wall
131
The layer of Cell which specifically holds different neighboring cells together in plants is __
Middle Lamella
132
Middle lamella in plants is composed of
Calcium pectate
133
The cell wall and middle lamellae are traversed by __
Plasmodesmata
134
Cytoplasm of neighboring cells are connected by __
Plasmodesmata
135
ER, Golgi complex, lysosomes, and vacuoles are part of __ system
Endomembrane system
136
The organelles whose functions are coordinated are considered as a part of __ system
Endomembrane system
137
Name three organelles which are not a part of the endomembrane system
Mitochondria, chloroplast, and peroxisomes
138
The organelle which divides intracellular space into luminal and extra luminal is __
Endoplasmic reticulum
139
The reticulum of tiny tubular structures scattered in the cytoplasm is called __
endoplasmic reticulum
140
The region inside ER is called
luminal
141
The region outside ER is called
extra luminal
142
The ER often shows ___ attached to their outer surface.
ribosomes
143
The endoplasmic reticulum bearing ribosomes on their surface is called __
Rough endoplasmic reticulum (RER)
144
The ER devoid of ribosomes is called as __
Smooth endoplasmic reticulum (SER)
145
The ER involved in active protein synthesis is __
RER
146
RER is __ and continuous with the outer membrane of the ___
extensive; nucleus
147
The site of lipid synthesis in ER is __
Smooth endoplasmic reticulum
148
Lipid-like steroidal hormones in animals cells are synthesized by __
SER
149
Golgi bodies were first observed by __
Camillo Golgi
150
Flat, disc-shaped sacs near the nucleus are called __
Golgi bodies
151
The diameter of sacs of Golgi varies from __ to __
0-5 μm; 1 μm
152
The cisternae of Golgi are arranged in __ form.
Parallel
153
The Golgi cisternae around the nucleus are arranged __
Concentrically
154
The forming face of the Golgi body is called __
Convex cis
155
Concave trans is the __ face of Golgi body
Maturing
156
The primary function of Golgi apparatus is __
Packaging of materials
157
Materials to be packaged in the form of vesicles from ER fuse with which face of Golgi?
Cis
158
Proteins synthesized by ribosomes are modified by
Golgi apparatus
159
Modified proteins from cisternae are released through __ of Golgi apparatus
trans face
160
Golgi apparatus is an important site for the formation of _ and _
glycoproteins and glycolipids
161
Membrane-bound vesicular structures formed by the process of packaging in the Golgi apparatus are called
Lysosomes
162
Which organelle forms lysosomes?
Golgi apparatus
163
Lysosomal vesicles are rich in __
Hydrolytic enzymes
164
The hydrolases present in lysosomes are -
Lipases, proteases, carbohydrases
165
Enzymes of lysosomal vesicles get active at __ pH
Acidic
166
Carbohydrates, proteins, lipids, and nucleic acids in lysosomes are digested by an enzyme
Hydrolases enzyme
167
The membrane-bound space found in cytoplasm is
Vacuole
168
Water, sap, and excretory waste are stored in
Vacuoles
169
The vacuole is bound by a single membrane called
Tonoplast
170
Vacuoles can occupy up to how much volume of a plant cell?
90%
171
The transport of a number of ions and other materials against concentration gradients into the vacuole is facilitated by __
Tonoplast
172
The vacuole responsible for osmoregulation and excretion in Amoeba is __
contractile vacuole
173
Food vacuoles are formed by engulfing food particles in __
Protists
174
The number of mitochondria in a cell depends on __ of the cell.
physiological activity
175
The diameter of mitochondria varies from _ to _
0.2 to1 μm
176
The length of mitochondria varies from _ to _
1 to 4.1 μm
177
Each mitochondrion is a ___ structure.
double membrane-bound
178
The inner compartment of mitochondria is filled with a dense homogeneous substance called __
Matrix
179
The membrane of mitochondria forming the continuous limiting boundary of the organelle is __
Outer mitochondrial membrane
180
The inner mitochondrial membrane forms a number of infoldings called __
Cristae
181
The infoldings increasing the surface area of mitochondria are __
Cristae
182
Mitochondria is the site of which respiration?
Aerobic respiration
183
Energy is released by mitochondria in the form of __
ATP
184
Mitochondria are also called _
Powerhouse of Cell
185
The ribosomal subunits present in a mitochondrial matrix are __
70S
186
Mitochondria divide by __
Fission
187
The pigment imparting organelles present in plants and some euglenoids is __
Plastid
188
Plastids are classified into Chloroplast, leucoplast, and chromoplast on the basis of __
Pigments
189
Chlorophyll containing plastids are called __
Chloroplasts
190
Along with chlorophyll, chloroplast contains __
Carotenoid pigments
191
Light energy trapped by pigments of chloroplast is required for __
Photosynthesis
192
Name two carotenoid pigments of Chloroplast.
Carotene and xanthophyll
193
The three colors provided to plants by chloroplasts are __
yellow, orange or red colour
194
The colorless plastids are called __
Leucoplasts
195
The function of leucoplast is to __
store nutrients
196
Carbohydrate-storing leucoplasts are called __
Amyloplasts
197
Leucoplast storing oils and fats is called __
Elaioplasts
198
Protein-storing leucoplast is known as __
Aleuroplasts
199
The majority of chloroplast of green plants is found in which cells?
Mesophyll cells
200
The number of chloroplasts in Chlamydomonas is __ per cell.
one
201
Number of chloroplasts in a mesophyll cell is __ per cell.
20-40
202
__ chloroplast membrane is less permeable
Inner
203
The space limited by inner membrane of the chloroplast is called __
Stroma
204
Thylakoids are present in __
Stroma
205
A number of organized flattened membranous sacs present in the stroma are called __
Thylakoids
206
Thylakoids are arranged in piles called __
Grana
207
The flat membranous tubule joining thylakoids of different grana are called __
stroma lamellae
208
The stroma of the chloroplast contains enzymes required for the synthesis of _ and _
carbohydrates and proteins
209
The pigments present in thylakoids are called __
Chlorophyll pigments
210
The ribosomal subunit present in chloroplasts is __
70S
211
Ribosomes were first observed under an electron microscope by __
George Palade
212
Ribosomes are composed of _ and _
RNA and proteins
213
The membrane-less, protein-synthesizing organelles are called __
Ribosomes
214
The eukaryotic ribosome is __S.
80S
215
The prokaryotic ribosome is __S.
70S
216
The two subunits of 80S ribosome are __
60S and 40S
217
The two subunits of 70S ribosome are __
50S and 30S
218
S (Svedberg's Unit) in ribosomal subunit stands for __
Sedimentation coefficient
219
Sedimentation coefficient is the measure of _ and _
density and size
220
An elaborate network of filamentous proteinaceous structures consisting of microtubules, microfilaments, and intermediate filaments present in the cytoplasm is collectively referred to as __
Cytoskeleton
221
Cytoskeleton is composed of proteinaceous structures like __
microtubules, microfilaments, and intermediate filaments
222
Two hair-like outgrowths of the cell membrane are __
Cilia and flagella
223
The small structures causing movement of either cell or surrounding fluid are called __
Cilium
224
An extension longer than cilia which is responsible for cellular movement, is __
Flagella
225
Cilium and flagellum are covered by __
Plasma membrane
226
The core of flagellum or cilium is called __
axoneme
227
Axoneme consists of a number of __ running in parallel to long axis.
microtubules
228
Axoneme has __ of radially arranged peripheral microtubules
nine doublets
229
The arrangement of axonemal microtubules is called
9+2 array
230
Central sheath is connected to one of the tubules of each peripheral doublet by
radial spoke
231
The number of radial spokes in 9+2 arrangement is
Nine
232
Peripheral doublets are interconnected by
linkers
233
The cilium and flagellum emerge from Centriole like structure called
basal bodies
234
An organelle usually containing two cylindrical structures called centrioles is called
Centrosome
235
Centrosomes are surrounded by
amorphous pericentriolar material
236
Centrioles in centrosome lie __ to each other
perpendicular
237
Centriole are made up of __ evenly spaced peripheral fibrils of tubulin protein.
nine
238
The protein forming peripheral fibrils in centriole is
Tubulin protein
239
Each of the __ in centriole is a triplet
peripheral fibril
240
The proteinaceous, central part of Proximal region of Centriole is called
hub
241
Hub is connected with tubules of peripheral triplets by
radial spokes
242
Radial spokes are composed of
Protein
243
The basal body of cilia or flagella is formed by
Centrioles
244
The basal body of spindle fibers is formed of
Centriole
245
The nucleus was first described by
Robert Brown
246
The material of the nucleus stained by the basic dyes was
given the name chromatin by
Flemming
247
The nucleolus, chromatin, and nuclear matrix are characteristics of which nucleus?
Interphase nucleus
248
The space between two parallel membranes of Nuclear envelope is called
perinuclear space
249
The outer membrane of Nucleus remains continuous with
endoplasmic reticulum
250
The outer membrane of Nucleus remains continuous with ER and bears.
ribosomes
251
Movement of RNA and protein between Nucleus and cytoplasm takes place through
nuclear pores
252
Some mature cells in mammals lacking Nuclue are
Erythrocytes
253
The plant cells devoid of a Nucleus are
Sieve tube cells
254
The nuclear matrix or the Nucleoplasm contains __ and __.
nucleolus and chromatin
255
The spherical structures present in nucleoplasm are called
nucleoli
256
The site of active ribosomal RNA synthesis in Nucleus is
Nucleolus
257
Chromatin primarily contains
DNA
258
Basic proteins present in chromatin are
histones
259
Human beings have __ pairs of chromosomes.
23
260
The primary constriction on chromosomes is called
Centromere
261
Kinetochores are present on the sides of
Centromere
262
The disc-shaped structures present on the sides of the centromere are called
Kinetochores
263
A chromosome having a middle centromere forming two equal arms of the chromosome is called
Metacentric chromosome
264
A chromosome whose centromere is slightly away from the middle of chromosome resulting in one shorter and one longer arm is called
sub-metacentric chromosome
265
The centromere is situated close to its end forming one extremely short and one very long arm in __ chromosome.
acrocentric chromosome
266
Chromosomes having terminal centromere are called
chromosome
267
Secondary constriction in chromosomes gives appearance of __
satellite
268
Minute enzyme-containing vesicles in both plants and animals, are called
Microbodies
269
Each mitochondrion is a double membrane-bound structure with the outer membrane and the inner membrane dividing its lumen distinctly into ___ compartments.
two aqueous compartments,
