Sunday, 21 August 2016

CELL WALL (117 Qs)

All bacteria, blue-green algae, fungi and plant cells (except mycoplasmas & slime molds) are surrounded and protected by a mechanical and rigid layer called cell wall. This is the layer which gives certain shape to an individual cell or the overall organism.

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QUESTIONS & ANSWERS

1) What are the different cell wall containing organisms?
A) Prokarotes (bacteria & blue green algae), fungi and plants
2) What is the major difference between a plant cell and an animalcell?
A) Presence of cell wall
3) What are the prokaryotic cells without cell walls?
A) Mycoplasmas
4) What is the outermost layer of plant cells?
A) Cell wall
5) Which part of the plant cell provides rigidity and mechanical support?
A) Cell wall
6) Which part of the cell is helpful in the morphodgensis of plants?
A) Cell wall
7) Which part is helpful in protecting a plant cell against osmotic lysis?
A) Cell wall
8) What are two factors that provide rigidity to plant cells?
A) Hydraulic turgor and cell wall structure
9) What are the pressure vessels that  prevent over-expansion or bursting of plant cells due to excess entry of water?
A) Cell walls
10) Who first observed cell wall?
A) Robert Hooke
11) Who coined the term cell wall?
A) Robert Hooke
12) Who were the supporters of the apposition or lamellar theory of cell wall formation?
A) Hugo Von Mohl & Edward Strasburger 
13) Who were the supporters of the intursusception theory of cell wall formation?
A) Carl Nageli & Julius Wiesner
14) Which is the non-living part of the plant tissues?
A) Apoplast
15) Which is the living part of the plant tissues?
A) Symplast
16) Who coined the term apoplast?
A) Munch
17) Which is the extracellular matrix in plant cells?
A) Cell wall
18) What are the different layers of a typical cell wall?
A) Middle lamella, primary wall, secondary wall and tertiary wall
19) Which is the first formed cell wall layer?
A) Middle lamella
20) What is the basic structure on which the middle lamella will be formed?
A) Cell plate
21) What is the chief component of middle lamella?
A) Calcium and magnesium pectate
22) Which cementing layer holds all the cells in a plant tissue?
A) Middle lamella
23) What is the chief organic substance in middle lamella?
A) Pectin
24) What are the chief inorganic elements in middle lamella?
A) Calcium and magnesium
25) Which is the outermost layer of a plant cell wall?
A) Middle lamella
26) What are the polysaccharides in primary cell walls?
A) Cellulose, hemicellulose and pectin
27) Which enzyme catalyses the formation of cellulose cell wall?
A) Cellulose synthase
28) Which enzyme catalyses the disorganization of cellulose cell wall?
A) Cellulase
29) Which is the most abundant macromolecule on the earth?
A) Cellulose
30) Which is the most abundant protein on the earth?
A) Rubisco
31) What is the chief carbohydrate in plant cell walls?
A) Cellulose
32) What is the chief component of the primary wall, secondary wall or tertiary wall?
A) Cellulose
33) What is the chief component of bacterial cell walls?
A) Peptidoglycan, murein or muramic acid
34) What are the chemical components of the cell walls of gram positive bacteria?
A) Peptidoglycon & teichoic acid
35) What kind of bacteria contain a thin peptidoglyconic cell wall with a membrane made of  lipo-polysacccharides and lipoproteins?
A) Gram negative bacteria
36) What kind of bacteria do not contain peptidoglyconic cell walls?
A) Archaebacteria
37) Which group of archaebacteria contains pseudo-peptidoglycon in cell walls?
A) Methanogens
38) Which chemical is used to stain bacterial cell walls?
A) Gram stain
39) What are the two types of cell walls in bacteria?
A) Gram positive and gram negative
40) What kind of bacteria have thick cell walls?
A) Gram positive bacteria
41) What kind of bacteria have thin cell walls?
A) Gram negative bacteria
42) What are the major kind of bacteria on the basis of the nature of their cell walls?
A) Gram negative bacteria
43) What are the cell wall materials of archaean bacteria?
A) Glycoprotein S-layers, pseudopeptidoglycan, or polysaccharides
44) What is the glucosamine polymer in the cell walls of fungi?
A) Chitin
45) What are the fungi that contain cellulose cell walls?
A) Slime molds
46) What are the materials in the algal cell walls?
A) Glycoproteins and polysaccharides
47) What is the chief component in the algal cell walls?
A) Cellulose
48) What is the characteristic polysaccharide in the cell walls of brown algae (Phaeophyceae)?
A) Alginic acid
49) What kind of algae generally contain sulfonated polysaccharides like  agarose, carrageenan, porphyran, furcelleran and funoran?
A) Red algae (Rhodophyceae)
50) What is the characteristic cell wall material obtained from Gelidium, a red alga?
A) Agar-agar
51) What is the silicitated covering over the cell walls of foraminiferans?
A) Testa
52) Which group of alga contains biogenic silica in their cell walls?
A) Diatoms
53) What is the extracellular matrix around the cell walls of diatoms fromed of silicic acid?
A) Frustule or valve
54) Which chemical element in cell walls is an adaptation to protect grasses from herbivorous animals?
A) Silica
55) Which cell wall material gives flexibility to collenchyma?
A) Pectin
56) What kind of tissues possess only primary walls?
A) Meristems & Parenchyma
57) Which cell wall layer can allow the plant cell to grow?
A) Primary wall
58) What is the major component of secondary walls?
A) Cellulose
59) What is the phenolic polymer in secondary walls?
A) Lignin
60) What is the chief component of secondary wall of  sclerenchyma and teacheary elements?
A) Lignin
61) What are casparian thickenings on root endodermis made of?
A) Suberin
62) What is the chief component of  cork cell walls?
A) Suberin
63) What is the chief component of tertiary walls in  the trachieds of gymnosperms?
A) Xylan
64) Which chemical group chiefly constitutes cell walls?
A) Carbohydrates  (Polysaccharides)
65) What is a group of 100 glucose chains?
A) Micelle
66) What is a group of 20 micelles?
A) Microfibril
67) What is a group of 250 microfibrils?
A) Macrofibril
68) In which cell wall layer microfibrils are randomly arranged?
A) Primary wall
69) In which cell wall layer  microfibrils are parallelly  arranged?
A) Secondary wall
70) What is the matrix substance in middle lamella and cell walls?
A) Pectin
71) What is the most common hemicellulose in the primary cell wall?
A)  Xyloglucan
72) What is the most common hemicellulose in the primary cell wall of grasses?
A) Glucuron arabino xylan
73) What is the characteristic type of growth in cell walls?
A) Acid growth
74) Name the protein that catalyses the growth of cell walls.
A) Expansin
75) What is the permeability barrier over the epidermal cells exposed to atmosphere?
A) Cuticle
76) What are the chief components of cuticle?
A) Cutin & wax
77) What are the plant parts without cuticle?
A) Underground or submerged parts in water
78) What is the Intercellular cytoplasmic bridges between plant  cells?
A) Plasmodesmata
79) What is the extension of endoplasmic reticulum inside the plasmodesmata?
A) Desmotubule
80) What are the channels through which the protoplasts of all cells are interconnected to form a symplast?
A) Plasmodesmata
81) What are the interruptions on the surface of cell walls ?
A) Pits
82) What are the openings of plasmodesmata  on the surface of cell walls ?
A) Pits
83) What are the characteristic depressions on the surface of cell walls ? A) Pits
84) What are the parts of a pit pair?
A) pit opening,  pit cavity, pit membrane and middle lamella
85) What are the depression like pits on the primary cell wall?
A) Primary pit fields or primordial pits or primary pits
86) What kind of pit fields are found on primary walls of parenchyma?
A) Primary pit fields
87) What kind of pits are present between parenchyma  cells?
A) Simple pits
88) What kind of pits are present between tracheids or vessel elements?
A) Bordered pits
89) In which group of plants heterogeneous bordered pits are present?
A) Gymnosperms
90) What is the circular thickening at the centre of the middle lamella of a bordered pit in gymnosperms?
A) Torus
91) What is the membrane that covers the torus?
A)  Margo.
92) What kind of pits present  between parenchyma cells and tracheids or vessel elements?
A) Half-bordered pits
93) How are called the ladder like payttern of pit distribution on tracheary elements?
A) Scalariform pitting
94) What kind of pits have uniform diameter?
A) Simple pits
95) What kind of pits have non-uniform diameter?
A) Bordered pits
96) What kind of pits have an over-arche?
A) Bordered pits
97) What is the waxy layer on cell walls to reduce water loss?
A) Cuticle
98) Which is the chief part of the apoplast in plant tissues?
A) Cell wall
99) Which is the chief part of symplast in plant tissues?
A) Cytoplasm or Protoplasm
100) What is the deciding factor for a plant architecture? 
A) Cell wall
101) Which part of the plant cell provides roughages in human diet?
A) Cell wall
102) Which is the most abundant hemicellulose in plant cell walls?
A) Xyloglucan
103) Which component of the fruit cell walls gives consistency in making jams and jellies?
A) Pectin
104) What kind of chemical bonds lie between microfibrils in cell walls?
A) Hydrogen bonds
105) Which chemical substance provides tensile strength to bast fibres?
A) Lignin
106) Which is the major component of wood?
A) Secondary wall (Cellulose)
107) Which is the major component of biomass that can be converted into biofuels?
A) Secondary wall
108) What is the chief component of paper, cotton fibres and wood pulp?
A) Cellulose
109) Which cell wall layers are universal in all plant cells?
A) Middle lamella & primary wall only
110) Which adhesive organic substance joins plant cells?
A) Pectin
111) What is the  jelly like substance in ripened guava fruits?
A) Pectin
112) What are the fungi without cell walls in their vegetative structures but in reproductive structures?
A) Slime molds
113) Which group of algae provides agar-agar as solidifying agent in the microbial culture media?
A) Rhodophyceae  (Red algae)
114) Who discovered agar-agar?
A) Mino Tarozaemon
115) What is the polysaccharide from which agar is derived?
A) Agarose + Agaropectin
116) What are the two red algae from which commercial agar is extracted?
A) Gelidium and Gracilaria
117) What is the dry pulpy residue full of cell walls, which is left after the extraction of juice from sugar cane?
A) Bagasse

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