extracellular matrix// jims tissues and epithelia Flashcards
basic components of plant ECM
which is the cell wall
middle lamella, primary cell wall, secondary cell wall
sugar fibres in sugar background
basic component so of animal ECM
which is connective tissue
collagen and elastic fibres, ground substance
protein fibre in sugar background
~definition~
what is a ECM? (generalised)
(polysachharide or protein) fibres embedded in saccharide jelly-like matrix
How does the cell wall (ECM) of plant have high tensile strength?
it is strong due to turgor pressure
common feature/characterstics of ECM
high tensile strength
compression resistant as it can hold water
which of these is not a basic animal tissue epithelium muscle pancreas nerve
pancreas tissue!!
which of these is not a basic plant tissue dermal meristemic schlerenchymal vascular
OPTION C
> schelenchyma is ground tissue associated with xylem and phloem and gives structural support
whci tissue can give rise to a range of different plant tissue types (dividing, p/s, storage cells) collenchyma parencyma pavement cells phloem
OPTION B
makes up the ‘ground tissue’
why are epithleia made enetirely of cells?
A ECM not strong enog to fufill epithelia lfunction
B cells cannot syntesis ECM components
C form a pressure resistant enclosure to retain body fluid
D monitor and control transfer of materials betweenbody and its surroundingas
OPTION D
stratified epithelia are multilayered for what reason?
A allow easy transfer of materials form cell to cell
B early stage of epithelial development and eventually form a single layer
C surface cells can be damaged and worn away without affecting integrity of epithelial tissue
D allow secretion of basal lamina component s between cell layers
OPTION C
> ss. keratinised made of dead anucleate cells forming outer layer. tough, strongest AND waterproof covering
> s.s non-k has ALL layers living
which is not an epithelial function A absorption B dialysis C heat generation D protection E sensation F secretion
OPTION C
> dialysis means filtration!!
what is functional significance of collumnar epithelium?
A generate contractions to provide peristaltic movements
B make a thicker epithelium to protect underlying tissue
C provide lots of cytoplasm to power active transport
D prevent leakage across eputhlial layer
option C
> acive transport and absorption is key
>
Plant ECM fibres are made of A glycoprotein B glycosaminoglycan C polysaccharides D proteins
OPTION C
cellulose and hemicellulose crosslink to give a high tensile strength!
Animal ECM gel-like backgorund is made of A collagen B glycoprotein C glycosaminoglycan (GAGs) D hemicellulose
OPTION C
GAGs are long polysaccharide chains
> sulphated = larger Proteoglycans
> unsulphated = hyalonronic acid
why do plants wilt?
they lose their turgor pressure if not enough water
which ECM products resist compressive forces
A type1 collagen, elastin, fibronectin
B type 2 collagen. aggrecan, hyaluronan
C type3 collagen, pectic acid, link protein
D type4 collagen, laminin, hyaluronan
OPTION b
type 2 collgagen found in cartildge
>gel hold water which prevents spread of disease and gives compressive resitance,
> aggregan aggregates hyaloronan into long chains producing a large swelling pressure
which is made of fibrocartilidge? A articular surface of knee joint B suture joint of skulls C intervetebral disc D tracheal rings
OPTION C
> rest of them are hyaline cartilge
which cell type makes ECM of loose connective tissue, tendons, ligaments A chondrocyte B fibroblast C mast cell D mesenchymal cell
OPTION B
> mast cell is immune cell
> mesenchymal cell are stem cells
define ‘’ intramembranous ossficiation’’
A blood vessels invade developing tissue
B bone forms directly after condensation of mesenchymal cell
C bone forms from mesenchymal cell after a layer of cartilidge
D bone forms on membranes of precursor cells of osteocytes
OPTION B
> without cartildge is intramembranous differentiate into osteoblasts
> enochondrial ossification is mesenchymal–> cartilidge –> then bone! (option C)
function of epipyseal plate?
elongate the growth of long bones!
What is the true of collenchyma tissue in plants?
A Cells themselves are dead
B Can expand and elongate to accommodate growing tissues
C Important in wound repair
D Long slender cells
E Photosynthetic cells
OPTION B
Collenchyma is composed of thick, living cells and is found in the epidermis of stems and leaves.
> provides structural support for young growing tissues and can therefore expand to accommodate growing tissues
Which of the following is not a function of connective tissue cells? A Degrade extracellular matrix B Make extracellular matrix C Sense loading on extracellular matrix D Modify matrix according to load
OPTION A
where is pseudostatified epithleium found?
lines the repspiratory tract and lungs as its one layer so close to the blood supply
> also has cillia to waft mucus to tharynx
which type of epithia are good in active transport A simple squamous B cuboidal C columnar D stratified squamous non-k E stratified squamous keratinised
cuboidal and collumnar - have lots of mitch, golgi and lysosome to pump cells
Which of these is NOT an example of a immigrant cell? A Pericyte B Endothelial cell C Monocyte D Lymphocyte E Plasma cells
option B
this is a resident cell so stays in the same place
Dense fibrous connective tissue provides mechanical strength. There are two types of dense fibrous
connective tissue. Which of these is NOT true?
A Tendons and ligaments are an example of regular dense fibrous connective tissue
B Dermis is an example of irregular dense fibrous connective tissue
C Regular is characterised by parallel bundles of collagen fibres
D Irregular is characterised by woven bundles of collagen fibres
E Irregular is characterised by parallel bundles of collagen fibres
OPTION E
common sense - irregular wouldn’t be parallel
> regular = tendon | irregualr = dermis
what is the function of squamous epithelium?
acts as a filter
aslo very thin so has short diffusion pathway so useful in blood vessels
what is the middle lamella made of? how does this help with forming a gel?
PECTIN which has high electrostatic charge = attract polar H20 making ECM compression resistant
> Ca2+ and Mg2+ helps with hydration too
which type of collagen arranges it into tropocollagen?
TYPE 3 COLLAGEN - trimer / three
> alpha helix chains arranged in a trimer = strength and can from fibrils and fibres (like rope)
what is the secondary cell wall made of
A cellulose, hemicellulose, and glycoproteins
B cellulose, hemicellulose and lignin
C cellulose, hemicellulose, lignin, glycoproteins and polysaccharides
D cellulose, lignin, and polysaccharides
E cellulose, lignin, glycoproteins and polysaccharides
OPTION D
no enzymes or proteins in seocndary cell wall
> lignin is less permeanble and less flexible (e.g. wood is mostly secondary cell wall)
Which statements about meristems is false?
Sites of growth
Differentiated parenchymal cells
Apical sites of growth for roots and shoots
Primary function - increase height and length
Secondary function - vascular cambium, new xylem and phloem production, wood formation
OPTION B
merostemic tissue made of UNdifferentiated parenchymal cells
Which statements about plant ECM is false?
Made almost entirely of carbohydrates
Very low protein content
Thick fibres of cellulose
Cross links of thick cellulose fibres
Embedded in gel of negatively charged polysaccharides
OPTION D
>Cross links made of thin hemicellulose fibres
What is the middle lamella of a plant cell wall made up of?
A Cellulose, pectin, pectic acid and a small amount of protein
B Cellulose, hemicellulose, pectin and a small amount of protein
C Pectin, pectic acid and a small amount of protein
D Pectin, pectic acid, a small amount of protein and enzymes
E Cellulose, pectin, pectic acid, a small amount of protein and enzymes
OPTION C
no cellulose or hmeicclisue or enzymes here!
