Chapter 1 - Cell Flashcards
1
Q
_______ was an outstanding figure in the field of protein structure and as also the founder of madras school .
Als discovered triple helical structure of collagen ..
A
G.N.Ramachandran
2
Q
At Cambridge , G.N.Ramachandan met _______ .
A
Linus Pauling
3
Q
Who first saw and described a LIVE cell ?
A
Anton Von Leeuwenhoek
4
Q
______ discovered nucleus .
A
Robert brown
5
Q
_____ in the year ______ observed -all plants are composed of different kinds of cells which form the tissues of the plant .
A
Matthias Schleiden - a GERMAN BOTANIST
Year 1838
6
Q
_____ in the year ______ studied different types of animal cells and reported that cells have a PLASMA MEMBRANE .
A
Theodore Schwann-British zoologist
1839
7
Q
Presence of cell wall is a unique character of plant cells - was given by ?
A
Theodore Schwann
8
Q
______ proposed the hypothesis that the bodies of animals and plants are composed of cells and products of cells .
A
Theodore Schwann
9
Q
Echo formulated the cell theory ?
A
Schleiden and Schwann
10
Q
Out of Schleiden and Schwann , who was German and who was British and who was a zoologist and who a botanist ?
A
Schleiden - German botanist
Schwann - British zoologist
11
Q
Omnis cellula -e cellula was given by ______ in the year _________ .
A
Rudolf Virchow
1855
12
Q
Who modified the hypothesis of Schleiden and Schwann to give the cell theory a final shape ?
A
Rudolf Virchow -new cells arise from pre-existing cells
13
Q
2 postulates of cell theory -
A
1- all living organisms are composed of cells and products of cells
2-all cells arise from pre-existing cells
14
Q
The _____ is the main arena of cellular activities in both plant and animal cells .
A
Cytoplasm
15
Q
Various _____ reactions occur in the cytoplasm to keep the cell in the living state.
A
Chemical
16
Q
_____ cells lack membrane bound organelles .
A
Prokaryotic cells
17
Q
_____ are NON-MEMBRANE BOUND organelles found in both eukaryotic and prokaryotic cells .
A
Ribosomes
18
Q
Animal cells contain _____ which helps in cell division .
A
Centrosome - non membrane bound
19
Q
Centrosomes have membranes or not .
A
Non-membrane bound
20
Q
Size of mycoplasma =
A
0.3 um in length (micrometer )
21
Q
Size of bacteria in micrometer =
A
3 to 5 um
1-2 um given in the diagram
22
Q
Diameter of human RBCs -
A
7 um
23
Q
Longest cells=
A
Nerve cells
24
Q
PPLO and mycoplasma are Pro or eukaryotic ?
A
Prokaryotic
25
Size of a typical eukaryotic cell =
10-20 micrometer
26
Size of viruses .
0.02-0.2 micrometer
27
Size of PPLO-
0.1 um
28
All prokaryotes have a ______ surrounding the cell membrane .
Cell wall
| Exception-mycoplasma
29
The naked genetic material of prokaryotic cell is -
Genomic DNA - single chromosome/circular DNA 🧬
30
Many ______ have a small circular DNA outside the genomic DNA 🧬 called PLASMID .
Bacteria 🧫
31
The plasmid DNA confers certain unique ______ characters to bacteria 🧫.
Phenotypic
| Example- resistance to antibiotics
32
_____ is used to monitor bacterial transformations with foreign DNA .
Plasmid DNA
33
Prokaryotes have something unique in the form of -
Inclusions
34
Mesosome is a differentiated form of -
Plasma membrane
35
Mesosome is a characteristic of-
Prokaryotes
36
A specialised differentiated form of cell membrane called ______ is a characteristic of prokaryotes .
Mesosome
37
Infoldings of cell membrane found in prokaryotes-
Mesosome
38
Although each layer of the cell envelope performs a distinct function , they act together as a ________ unit .
Single PROTECTIVE unit
39
On what basis can bacteria be divided into 2 groups ?
1 -difference in the cell envelope
| 2 - how they respond to staining procedure
40
Those bacteria which take up gram stain are called _______ and those which do not are called ________ .
Gram positive
| Gram negative
41
GLYCOCALYX differs in ______ and _________ among different bacteria 🧫.
Composition
| Thickness
42
Glycocalyx may be a loose sheath called ______ in some , while in others it may be thick and tough called _______ .
Slime layer
| Capsule
43
______ determines the shape of the cell and prevents it from bursting or collapsing .
Cell wall
44
Plasma membrane is ______ permeable .
Selectively -interacts with the outside world 🌍
45
______ is similar structurally to that of the eukaryotes .
| Cell wall/membrane
Cell membrane
46
________ interacts with the outside world and is selectively permeable .
Cell membrane
47
Membranous structure called mesosome is formed by the extension of plasma membrane into the ______ .
Cell
48
The extensions called mesosomes are in the form of ___ ,_____ and ______.
Vesicles
Tubules
Lamellae
49
Functions of mesosomes -
Cell wall formation
DNA replication and distribution to daughter cells
Respiration and secretion , to increase the surface area of the plasma membrane and enzymatic content .
50
Mesosomes help in _______and ________ processes to increase the surface area of the plasma membrane and enzymatic content .
Respiration
| Secretion
51
Bacterial cells are motile/non-motile.
May be motile or non-motile
52
Bacteria show a range in the _____ and ______ of flagella .
Number
| Arrangement
53
Bacterial flagella is composed of how many parts ?
3
Filament
Hook
Basal body
54
In the bacterial flagella , _____ is the longest portion and extends from the cell surface to the outside .
Filament
55
_____ and _____ are surface structures but do not play a role in motility . They attach the bacteria to rocks in streams and to the host tissues
Pili
| Fimbrae
56
___ are elongated tubular structures made of special proteins .
______ are small bristle-like fibres sprouting out of the cell .
Pili
| Fimbriae
57
Apart from mesosomes , other membranous extensions into the cytoplasm seen in CYANOBACTERIA are called -
Chromatophores-pigmented
58
Chromatophores and mesosomes are ______ extensions in PROKARYOTES .
Membranous
59
In prokaryotes , ribosomes are associated with the _______ of the cell .
Plasma membrane
60
Ribosomes in prokaryotes are __________ in size .
15nm by 20nm
61
Ribosomes in prokaryotes are made of _____ and _____ units which when present together form _____ ribosomes .
50S and 30S
| 70S
62
In prokaryotes , several ribosomes may attach to a `single mRNA` and form a chain called -
Polyribosome / polysome
63
The ribosomes of a ______ translate the mRNA into proteins .
Polysome
64
Reserve materials in PROKARYOTIC cells are stored in the cytoplasm in the form of -
Inclusion bodies
65
Inclusion bodies are not bound by any membrane system and lie freely in the cytoplasm . T/F
T
66
Examples of inclusion bodies .
Phosphate granules
Cyanophycean granules
Glycogen granules
(Gas vacuoles -maybe )
67
Gas vacuoles are found in -
Blue green , purple and green photosynthetic bacteria
Or
BGA
Purple and green photosynthetic bacteria
68
In ______ cells , there is a extensive compartmentalisation of cytoplasm through the presence of membrane bound organelles .
Eukaryotic
69
The genetic material of eukaryotes is organised into -
Chromosomes
70
The detailed structure of cell membrane was studied only after the advent of ______ in the ______ .
Electron microscope 🔬
| 1950s
71
Chemical studies on the cell membrane in ________ enabled the scientists to deduce the possible structure of cell membrane. .
Human RBC
72
Studies on human RBC showed that cell membrane is mainly composed of ______ and ______ .
Lipids
| Proteins
73
The major lipid of plasma membrane is arranged in a -
Bilayer
| Major lipid-phospholipid
74
The lipids are arranged within the membrane with the ________ towards the outer side and ______ towards the inner part.
Polar head -outer
| Hydrophobic / non-polar tail -inner
75
The non-polar tail of SATURATED hydrocarbons is protected from __________ ( in the plasma membrane structure ).
Aqueous environment
76
In addition to phospholipids , the plasma membrane also contains -
Cholesterol
77
Later , BIOCHEMICAL investigation clearly revealed that the cell membrane also possess _____ and _____ .
Proteins
| Carbohydrates
78
The ratio of _____ and ____ vary in different types of cells membranes in cells .
Proteins
| Lipid
79
In the cell membrane of human RBCs _____ % of proteins and ______ % of lipids are found .
52% proteins
| 40% lipids
80
Depending on the ease of EXTRACTION , membrane proteins can be classified as ______ and ______ .
Integral
| Peripheral
81
_____ proteins are partially or wholly buried in the cell membrane .
Integral
While peripheral proteins lie on the surface
82
An improved model of the structure of cell membrane was proposed by _____ and ______ in the year _______ .
Singer and nicolson
| 1972
83
According to fluid mosaic model , ________ nature of lipid enables lateral movement of proteins within the overall bilayer .
Quasi-fluid
84
The ability of lipid and proteins to move within the membrane is measured as its _______.
Fluidity
85
The FLUID nature of the membrane is important from the point of view of functions like-
```
Cell growth
Formation of intercellular junctions
Secretion
Endocytosis
Cell division
```
86
One of the MST important functions of plasma membrane is -
Transport of molecules across it
87
neutral molecules move across the plasma membrane by the process________ .
Simple diffusion -along the conc gradient ( from high conc to low )
88
The ______ molecules cannot pass through the _______ lipid bilayer .
(Polar/non-polar)
Polar
| Non-polar
89
How are polar molecules transported across the plasma membrane through which process?
They require a carrier protein of the membrane to facilitate their transport across the membrane . Facilitated transport .
90
Some ions are transported across the membrane against their conc gradient . This process is energy dependent and utilises ATP and is called -
Active transport
| Na / K pump
91
Active transport across plasma membrane is an ______ dependent process .
Energy
92
Cell wall is living or not ?
Non-living
93
Cell wall forms the outer covering for the ______ in plants and animals .
Cell membrane
94
______ helps in cell-to-cell interaction and provides barrier to undesirable MACROMOLECULES .
Cell wall
95
Algae have a cell wall made of -
Cellulose
Gala tans
Mannans
Calcium carbonate
96
Generally , in plants , cell wall is made up of -
Cellulose
Hemicellulose
Pectins
Proteins
97
The cell of a young plant , the ________ wall is capable of GROWTH which gradually diminishes as the cell matures and the _____ wall is formed .
Primary
| Secondary
98
Secondary wall of the CELL WALL is formed on the ______ side of the cell .
Inner side-towards membrane
99
Function of middle lamella -
Holds or glues the different neighbouring cells together
100
The middle lamella is a layer of _____ .
Calcium pectate
101
The ______ and _______ may be traversed by plasmodesmata which connect the cytoplasm of neighbouring cells .
Cell wall
| Middle lamella
102
Many MEMBRANOUS organelles are considered together as an endomembrane system because -
Their functions are coordinated
103
Organelles which are a part of an endomembrane system -
```
4
ER
Golgi apparatus
Lysosomes
Vacuoles
```
104
_____ divides the intracellular space into 2 parts compartments ( luminal and extra luminal )
ER
105
ER divides the INTRACELLULAR space into which distinct compartments .
Luminal - inside ER
| Extra luminal -cytoplasm
106
The ER often shows ribosomes attached to the _____ surface .
Outer
107
In the absence of ______ ,ER appears smooth .
Ribosomes
108
RER is frequently observed in cells actively involved in ________ and _______ .
Protein synthesis
| Secretion
109
______ are EXTENSIVE and continuous with the outer membrane of the nucleus .
RER
110
______ is the major site for the synthesis of lipids .
SER
111
In animal cells _______ are synthesised in SER .
LIPID-LIKE STEROIDAL HORMONES
112
Functions of RER ans SER ,
RER SER
Protein synthesis. Synthesis of lipids and lipid-like steroidal
Secretion Hormones
113
______ in the year ______ observed densely stained reticular structure near the nucleus .
Camillo Golgi
| 1898
114
Golgi bodies are DENSELY STAINED RETICULAR structures near the ______ .
Nucleus
115
Golgi apparatus consist of flat , ______ shaped sacs or _____ .
Disc-shaped
| Cisternae
116
Cisternae of Golgi apparatus are ___ to ______ in diameter .
0.5 to 1.0 um
117
______ are packed parallel to each other in Golgi apparatus .
Also
Varied number of_____ are present in a Golgi complex .
(Same answer for both )
Cisternae
118
The Golgi cisternae are _______ arranged near the nucleus .
Concentrically
119
In the Golgi apparatus , the convex face is called ____ and is the ____face , While
The concave face is called the trans and is the ______ face .
CIS- forming
| Trans -maturing
120
The cis and trans faces of Golgi body are interconnected but are entirely same/different .
Different
121
Function of Golgi apparatus -
Packaging materials ,to be delivered to intra-cellular targets or secreted outside the cell .
Secretion of glycoproteins and glycolipids.
122
Packed paterials in Golgi body are delivered to ______ or secreted _____.
Intra-cellular targets
| Outside the cell
123
Materials to be packaged in the form of _______ from the ER fuse with the ____ face of Golgi apparatus and move towards the ____face.
Vesicles
CIS
Maturing-trans
124
Why does Golgi apparatus remain in close association with the ER ?
Because materials to be packaged in the form of vesicles from ER fuse with the cis face and move towards the trans face . Proteins synthesised by ribosomes on ER are modified in the cisternae of the Golgi app before being released from the trans face .
125
Golgi app is the important site for the synthesis of ___ and _____ .
Glycoproteins
| Glycolipids
126
Proteins synthesised by ribosomes not he ER are modified in the _______________________.
Cisternae of Golgi app , and afterwards released from the trans face .
127
Glycolipids are synthesised in the ________ .
Golgi app
| Also , glycoproteins
128
Lysosomes are membrane / non-membrane bound .
Membrane bound
129
_____ are vesicular structures formed by the process of packaging in the Golgi app .
Lysosomes
130
The isolated lysosomal vesicles have been found to be very rich in almost all types of -
Hydrolytic enzymes ( hydrolases - lipases , protease , carbohydrates)
131
The hydrolytic enzymes of lysosomes are optimally active under_____ pH.
Acidic
132
The hydrolytic enzymes of lysosome are capable of digesting -
Carbohydrates
Proteins
Lipids
Nuclei acids
133
Function of lysosome -
The hydrolytic enzymes ( hydrolases) are capable of digesting carbs , protein , lipids , nucleic acids )
134
The vacuole contains_____ ,_______, _______ and________ .
Water
Sap
Excretory products
Other materials not useful for the cell
135
The vacuole is bound by a ____ membrane .
Single -tonopast
136
In plant cells ,the vacuoles can occupy upto _____ % of the volume of the cell .
90%
137
In plants , the tonoplast facilitates the transport of a number of IONS and other materials _______ the conc gradient _____ into / out of the vacuole .
Against
| Into
138
The concentration of tonoplast is higher in the _____ .
Vacuole , than in the cytoplasm
139
Why is the conc of tonoplast significantly higher in the vacuole than in the cytoplasm ?
Because , tonoplast facilitates the transport of ions AGAINST CONC GRADIENT INTO the vacuole .
140
In Amoeba , __ is important for osmoregulation
Contractile vacuole
141
In protists , ______ are formed for engulfing food particles .
Food vacuole
142
Mitochondria are clearly visible under microscope . T/F.
F
143
Mitochondria unless specifically ________ are not visible under the microscope .
Stained
144
The __ ,____ and ____ of mitochondria are variable per cell .
Number
Shape
Size
145
Size of mitochondria -
Sausage -shaped or cylindrical having diameter=0.2-1 um and length 1-4.1um .
146
The number of mitochondria per cell is variable depending on the -
Physiological activity of the cell
147
The outer and inner membrane of mitochondria divided its lumen into 2 ________ compartments .
Aqueous
148
The _____ of mitochondria is filled with dense homogenous matrix.
Inner compartment ( inside inner membrane )
149
The _______ forms the continuous limiting boundary of the mitochondria .
Outer membrane
150
The _______ forms a number of infoldings called cristae toward the ______ in mitochondria .
Inner membrane
| Matrix
151
The cristae of mitochondria _____ the surface area .
Increase
152
In mitochondria _______ have their own specific enzymes associated with the mitochondrial function .
Both the membranes
153
Mitochondria are the sites of _____ respiration .
Aerobic
154
The MATRIX of mitochondria possess ________ DNA molecules .(type)
Single circular
155
The MATRIX of mitochondria contains -
Single circular DNA molecules
Few RNA
Ribosomes(70S)
Components required for the synthesis of proteins
156
The mitochondria divide by________ .
Fission
157
The type of RNA in mitochondria .
70S
158
Plastids are found in all ______ and _______ .
Plant cells
| Euglenoids
159
These organelles are easily observed under the microscope .
Plastids - as they are large
| Mitochondria cannot be observed without staining
160
On what basis are plastids classified ?
On the type of pigments they contain .
161
Plastids are divided into -
3 categories
Chloroplast
Chromoplast
Leucoplast
162
The chloroplast contain ______ and _______ which are responsible for trapping light energy .
Cchlorophyll
| Carotenoid
163
In _______ , FAT soluble carotenoid pigments are present .(type of plastid )
Chromoplasts
164
In chromoplasts , fat soluble CAROTENOID pigments like ________ and __________ are present .
Carotene
| Xanthophyll
165
Which plastids are coloured ?
Chromoplast
| The carotenoid pigments ( carotene and xanthophyll ) give the plant YELLOW , ORANGE, or RED colours
166
Carotenoid pigments are ______ soluble .
Fat
167
The _______ are colourless plastids .
Leucoplast
168
The ________ are of varied shapes and sizes with stored NUTRIENTS .
( a type of plastid )
Leucoplasts
169
Types of leucoplast :
Amyloplast - carbohydrates (starch)
Elaioplasts-oil and fats
Aleuroplasts - proteins
170
An example of a plant with amyloplasts (form of leucoplast ).
Potato - stores starch
171
Elaioplasts store - .
Fats
| Oils
172
Majority of chloroplasts are found in the _________ cells of leaves .
MESOPHYLL cells
173
Different shapes of chloroplasts -
```
Lens-shaped
Oval
Spherical
Discoid
Ribbon-like
```
174
Chloroplasts have a length of _______ and width of _____.
5-10um
| 2-4um
175
Number of chloroplasts per cell in chlamydomonas ( green algae) -
1
176
Number of chloroplasts per cell in mesophyll of leaves is -
20-40
177
Out of the 2 membranes of chloroplast , which is less permeable ?
Inner
178
The space limited by ______ membrane of chloroplast is called STROMA .
Inner
179
A number of organised flattened MEMBRANOUS SACS called ______ are present in the stroma .
Thylakoids
180
______ are arranged in stacks like piles of coins .
Thylakoids
181
Thylakoids are arranged in stacks called ______ or _______ .
Grana
| Intergranal thylakoids
182
There are FLAT MEMBRANOUS TUBULES called _______ connecting the thylakoids of different grana .
STROMA lamella
183
What do stroma lammme connect ?
Thylakoids of different grana
184
The membrane of _______ encloses a space called LUMEN .
Thylakoid
185
The _______ of chloroplast contains enzymes required for the synthesis of CARBOHYDRATES and PROTEINS .
STROMA
186
LUMEN is the he space found in the ______ of thylakoids .
Inside the membrane
187
STROMA of chloroplasts contains what all substances -
enzymes for the synthesis of Carbs and proteins
Small , ds circular DNA
Ribosomes
188
Chlorophyll pigments are present in the ________.
Thylakoids
189
The ribosomes of chloroplast are _______ than the cytoplasmic ribosomes .
Smaller(70S)
| Cytoplasmic ribosomes are 80S
190
Type of DNA molecules present in chloroplasts -
Small , ds circular DNA
191
Ribosomes are granular / smooth structures first observed under the electron microscope as dense particles .
Granular
192
Who discovered ribosomes and in which year ?
George Palade
| 1953
193
Ribosomes are ______ membrane bound .
Non . Without any membrane
194
Ribosomes are composed of ____ and ________ .
RNA
| Proteins
195
The eukaryotic ribosomes are _____while the prokaryotic ones are _____ .
80S
| 70S
196
Each ribosomes has 2 subunits -
Smaller and larger
197
The 2 subunits of eukaryotic ribosome are
And
The 2 snunits of pro ribosomes -
```
80S = 60S +40S
70S = 50S +30S
```
198
S (Svedberg unit) stands for ______ and is an indirectly a measure of ______ and ______ .
Sedimentation coefficient
| Density and size
199
An elaborate network of FILAMENTOUS PROTENACEOUS structures consisting of MICROTUBULES , MICROFILAMENTS and intermediate filaments present in the cytoplasm are collectively referred to as -
Cytoskeleton
200
Cytoskelton is composed of -
MICROTUBULES
MICROFILAMENTS
Intermediate filaments
201
Functions of cytoskeleton -
Mechanical support
Motility
Maintenance of the shape of cell .
202
Cilia and flagella are hair like outgrowths of the ______ .
Cell membrane
203
______are small structures which work like oars , causing the movement of either the cell or the surrounding fliud .
Cilia
204
_______ is comparatively longer and responsible for CELL MOVEMENT .(cilia/flagella)
Flagella
205
How are prokaryotic FLAGELLA different from eukaryotic flagella ?
They are different STRUCTURALLY
206
Cilia and flagellum are covered with _______ .
Plasma membrane
207
The core of cilium or flagellum is called -
Anoxeme
208
The core o cilia and flagella called anoxeme possesses a number of ______ running PARALLEL to the long axis .
MICROTUBULES
209
The anoxeme has ______ DOUBLETS of RADIALLY ARRANGED PERIPHERAL MICROTUBULES and ______ centrally located MICROTUBULES .
9
| Pair
210
The arrangement of anoxemal MICROTUBULES is referred to as -
9+2 array
211
There are ______ radial spokes in anoxeme .
9
212
The ______ tubules of anoxeme are connected by bridges and also enclosed by _______ ,which is connected to one of the tubules of each peripheral doublet by a RADIAL SPOKE .
Central
| Central sheath
213
In anoxeme , the peripheral doublets are connected by -
Linkers
214
Both the cilium and flagellum emerge from centriole-structure called -
Basal bodies
215
CENTROSOME is an organelle containing _____ cylindrical structures called ____.
2
| Centrioles
216
Centrosome are surrounded by ______ materials .
Amorphous pericentriolar
217
Both the centrioles in a centrosome lie ______ to each other .
Perpendicular
218
Centrioles lie within ________ .
Centrosome
219
Each centriole in a centrosome has an organisation like the _____.
Cartwheel
220
The CENTRIOLES are made up of _____evenly spaced peripheral fibrils of _______ protein .
9
| Tubulin
221
Each peripheral FIBRIL of centriole is a _______ .
Triplet
222
The adjacent triplets of centriole are free . T/F
F
| They ar linked
223
The central part of the proximal region of the centriole is also protenaceous and is called -
Hub
224
The hub of centriole is connected with tubules of the peripheral triplets by ________ made up of PROTEINS .
Radial spokes
225
______forms the basal body of cilia and flagella .
Centriole
226
The _______ forms the spindle fibres that give rise to spindle app during cell division in animal cell .
Centriole. ( not centrosome )
| Centriole lies within centrosome
227
Anoxeme is the core of -
| And hub is the centre of -
Cilia and flagella
| Centriole
228
Nucleus was first described by Robert Brown in the year -
1831
229
The material of nucleus was stained by ______ basic/acidic dyes ad was given the name CHROMATIN by ________ .
Basic
| Flemming
230
Flemming named nuclear material as -
Chromatin
231
The ________ nucleus is the nucleus of the cell when it is not dividing .
Interphase
232
The interphase nucleus has highly extended and elaborate _______fibres called _____.
Nucleoprotein
| Chromatin
233
What does the interphase nucleus contain ?
Elaborate Nucleoprotein fibres called - chromatin
Nuclear matrix
One or more nucleoli ( spherical bodies )
234
Electron microscopy has revealed that nuclear envelope which consists of ______parallel membranes with a space between them called _________ .
2
| Perinuclear space
235
Width of perinuclear space -
10-50 nm
236
Function of perinuclear space -
Forms a barrier between materials present inside the nucleus and that of the cytoplasm .
237
The ______ membrane of the nucleus remains continuous with the ER and bears _____ on it .
Outer
| Ribosomes
238
_______ of nucleus bears ribosomes on it .
Outer membrane
239
At a number of places the nuclear envelope is interrupted by minute pores .how are they formed ?
Formed by the fusion of the 2 membranes of the nucleus .
240
Nuclear pores are the passages through which movement of _____ and _____ takes place between the nucleus and the cytoplasm .
RNA
| Protein molecules
241
Nuclear pores allow passage of RNA and protein molecules in - directions .
Both
242
Normally , there are ____ nuclei per cell .
Only 1
243
Name 2 cells which lack nucleus -
Mature RBCs of mammals
| SEIVE tube cells of vascular plants
244
The NUCLEAR MATRIX or NUCLEOPLASM contains -
Nucleoli
| Chromatin
245
The ______ are spherical structures present in the the nucleoplasm .
Nucleoli
246
Nucleolus is membrane / non-membrane bound .
Non-membrane bound
247
The contents of nucleolus are continuous with the rest of the ________ .
Cytoplasm
| As it is non-membrane bound
248
Nucleolus is the site of active _______ synthesis .
rRNA
249
Larger and more numerous ______ are present in cells actively carrying out protein synthesis .
Nucleoli
250
During different stages of cell division , cells show structured ________ in place of the NUCLEUS .
Chromosomes
251
_______ contains DNA and some basic proteins histones .
Chromatin
252
Components of chromatin -
DNA
Histones
Non-histones proteins
RNA
253
A single human cell has approx. ______ long thread of DNA , distributed among its 46 chromosomes .
2 Metre
254
Chromosomes are visible only in ________ cells .
Dividing
255
Every chromosome has a ________ constriction called CENTROMERE .
Primary
256
Where are disc-shaped structures called KINETOCHORES present ?
On the sides of centromere
257
Function of centromere -
Holds 2 chromatids of a chromosomes
258
On what basis are chromosomes classified into 4 types ?
Position of centromere
259
The _______ chromosome has a middle centromere forming 2 equal arms of the chromosome.
Metacentric
260
The ______ chromosome has centromere slightly away from the middle of the chromosome resulting in 1 shorter arm and other longer arm .
Sub-metacentric
261
In case of _______ chromosome , the centromere is situated close to its end forming one extremely short and one very long rm .
Acrocentric
262
_______ chromosome has a terminal centromere .
Telocentric
263
Satellites are staining / non-staining .
Non-staining
264
Satellites are ______ constrictions giving the appearance of small fragments .
Secondary
265
Satellites are present at different / constant locations .
Constant
266
Sometimes , FEW chromosomes have non-staining secondary constrictions called -
Satellites
267
Microbodies are present in plants/animals .
Both
268
Microbodies are membrane / non-membrane bound .
Membrane bound
269
Many membrane bound minute vesicles called ______ contain various enzymes .
Microbodies
270
L - shape is of _____ chromosome .
Sub-metacentric
271
I -shape is of _____ chromosome .
Telocentric
272
J-shape is of ______ chromosome .
Acrocentric
273
V-shape is of ______ chromosome .
Metacentric
