Cell structure and extracellular matrix Flashcards
What are the four basic plant tissues?
Dermal tissue/ epithelium
Vascular tissue
Ground tissue
Meristematic tissue
Where is epithelium found in plants?
Outer layers of stems, roots and leaves
1 inner layer in roots
State the function of vascular tissue.
Xylem transports water
Phloem transports sugars
Where is vascular tissue in plants?
Stems
Leaves
Roots
Function of ground tissue in plants.
Makes up bulk of plant mass: parenchyma, collenchyma and sclerenchyma
Where is ground tissue in plants?
Stems
Roots
Leaves
What is the function of meristematic tissue in plants?
Cell division to produce new growth
like stem cells in animals
Where is meristematic tissue found in plants?
Tips of shoots and roots
In buds
Around stem of woody plants
Describe the structure and function of parenchyma.
Thin cell walls Large vacuoles Dividing cells so found in meristems Storage cells in roots, stems and seeds May be air filled tissue in floating plants Pith
Describe the structure and function of collenchyma.
Structural support Growing shoots and leaves Living cells Thickened cell walls to cope with mechanical pressure exerted on them Beneath epidermis of stems and leaves
Describe the structure and function of sclerenchyma.
Main structural support of a plant
Long, slender cells bundled together
Thick cell walls, the cells are dead
Develop in association with xylem and phloem
Why are sclerenchyma commercially useful?
Fibres for fabrics
Flax for linen
Hemp for rope and fabric
What is the function of xylem?
Water transport
Transpiration
Root pressure
Capillary action
State the structure of xylem.
Columns of elongate dead cells with thick woody cell walls
Forms tubes
What is the function of phloem?
Transport organic nutrients, mostly sucrose
State the structure of phloem.
Made of cells linked end to end- sieve tubes
Highly specialised
Lost most of their internal structures that might slow fluid movement
Linked via specialised plasmodesmata
What are plasmodesmata?
Small channels that directly connect the cytoplasm of neighbouring plant cells to each other, establishing living bridges between cells
State the structure and function of meristems.
Sites of growth
Undifferentiated parenchymal cells
Generate new cells that can differentiate into new cell types as the developing structure matures
What are the four basic animal tissues?
Epithelium
Connective tissue
Muscle
Nerve
State the function of epithelium.
Protection (Poh) Secretion (Sleeps) Absorption (All) Dialysis (Day) Sensation (Stupidly)
State the function of connective tissue in animals.
Support
Linking
Binding
Space filling
State the function of muscle in animals.
Generate movement and heat
State the function of nerves in animals.
Communication
Where is epithelium found in animals?
Outer coverings Lining of gut Respiratory Urogenital system Etc
Where is connective tissue found in animals?
Widespread, as specific tissues and as parts of other structures e.g. bone, tendon, dermis, etc
Where is muscle found in animals?
Skeletal muscle
Heart
Smooth muscle
Widespread
Where are nerves found in animals?
CNS
PNS
Widespread
What is a tissue?
Collection of cells and/ or extracellular materials specialised for a particular function
Mostly grouped in a well-ordered arrangement
State three types of muscle
Cardiac muscle
Skeletal muscle
Smooth muscle
How many pints of cells are in the average human body? Hint: less than we usually drink at the taf
2
State three types of connective tissue.
Connective tissue proper
Cartilage
Bone
What is an organ? (In the body, not the instrument you weirdos)
A distinct, discrete functional unit formed from 2 or more tissues
What is an organ system?
Organ systems are assemblies of different organs associated with a particular process
What is simple epithelia?
Epithelia arranged in 1 layer
What is stratified epithelia?
Epithelia arranged in multiple layers
What is squamous epithelia?
Where the epithelial cells are wider than the height and look flat and scale-like
What is cuboidal epithelia?
The cells are cube shaped, duh
What is columnar epithelia?
The cells are taller than they are wide
Are epithelia avascular?
yeah boi
What does avascular mean?
Doesn’t have its own internal blood supply
What do epithelia sit on top of?
Sits on top of a basement membrane like Dylan sitting on Poh at the first HP social
What structures derive from epithelium?
Glands
What are keratinised eptihelial cells?
Cells that have filled themselves with keratin and other waxy molecules
The cells are non-living
Act as a barrier that is continuously replaced so can be worn away
Strong and waterproof
What are pseudostratified epithelia cells?
Looks stratified but isn’t
All cells connected to basement membrane just at different heights
What are transitional epithelium and where would we find them?
Lines the bladder and shifts between collapsed and stretched as bladder empties and fills
What are some features common to all epithelia?
They are entirely cellular
Specialised cell to cell junctions
Polarity (top surface is different from bottom surface)
Connected to a basement membrane
What are microvilli?
Finger-like projections which increase the surface area of the cell membrane to aid with absorption and secretion
What are cilia?
Cilia are motile structures, which project from the top of cells
What are basal striations?
Infoldings of the membrane at the base of the cell which increases surface area for energy dependent processes
What are the toughest epithelial cells and why?
Stratified squamous keratinised epithelium
Surface cells fill up with keratin
Tough, dead, waterproof covering
