Communicable Diseases Flashcards
what is a pathogen
an organism that causes disease
communicable disease defintiion (2)
pathogen which can be transmitted (1) disease is caused by effect of pathogen (2)
bateria features (2)
rapid reproduction (!) toxins & waste products damage cells (2)
how can bacteria be killed
antibiotics
what is the best place for bacteria to be present in a plant(2)
vascular tissue to then reach the rest of the plant (1) and nutrients available (2)
FIll in the gaps: Fungi forms …, a part of fungus consisting of network of fine white filaments
mycelium
FIll in the gaps: Fungi forms …, a part of fungus which releases spores for reproduction
hyphae
what part of fungi spreads disease
spores released by hyphae
what is the type of fungi that feeds on dead tissue
saprophytic fungus
what is the type of fungi that feeds on living tissue
parasitic fungi
where is most advantagous for fungi to develop on a plant
leaves = stops them photosynthesising & kills the plant
which pathogens are eukaryotes
protists, fungi
which pathogens are non living
virsuses
which pathogens are prokaryotes
bacteria
true or false all virsuses are pathogenic
true
true or false all fungi are pathogenic
false
structure of virsus (2)
genetic material (!) protein coat(2)
what is the purpose of protein coat in viruses (2)
shell to protect genome(1)
attaches to receptors on host cells (2)
function of virus (3)
invade & take over host cells genetic machinery (1)
causes cells to manufacture more copies of the virus (2)
eventually cell bursts, releasing virus to other cells (3)
true or false all protists are pathogenic
false (very few are pathogenic)
how does protists cause harm in cells (2)
enters host cells & feeds on its contents as they grow (“)
how do protisst reproduce
binary fission
3 modes of action of a pathogen on the host
- direct damage of tissues
production of toxins - digest cells (3)
name 3 bacterial diseases
tuberculosis, meningitis, ring rot
name 3 viral diseases
HIV, influenza, tobacco mosaic virus,
name 3 fungus diseases
black sigatoka, ring worm (in cattle), athletes foot
name 2 protists diseases
blight (plants), malaria
how does TB affect humans
kills cells & tissues, mainly lungs are affected
menegntisitis symptomes
membranes around brain and spinal chord become swollen = cause damage to brain and nerves
ring rot symptoms
ring of decay in vascular tissue of potato or tomato
HIV/ AIDS symptoms
attacks cells in immune system = compromsies immune system
influenza symptims
acctacks resporatory system & muscle pains & headaches
TMV symptoms
mottling & discoloration of leaves
black sigatoka symptoms
leaf spots on banana plants = reduces yield
blight symptoms
affects leaves and potato tubers
ringworm symptoms
growth of fungus in skin = rash
athletes foot
gorwth under feet’s skin
malaria symptoms
headaches & fever that may progress to coma & death
how is TB spread
indirect: droplet infection
how is meningitis spread
indirect: droplet infection or touching contaminated surfaces
how is HIV spread
sexual transmission/ sharing needle
how is influenza spread
indirect: droplet infection
how is malaria spread
by vector: female anopheles mosquito
transmission defintiion
the way in which a a parasitic microorganism travels from 1 host to another
methods of direct trasmisision
touched contaminated surfaces, inoculation, ingestion
methods of indirect trasmission
formites, droplet infection, vectors
what is inoculation
break in t he skin or puncture wound = pathogen can eneter
example of disease by inoculation
rabies
ingestion defnieion
eating conatimned foos or faeces on hands
formites definition
pathogen travels from 1 infected individual to another through the means of an unaffected object or organism
vectors defnition (3)
a living or non-living factor (1)that transmits a pathogen from 1 host to another(2) e.g malaria transmitted by mosquitos(3)
factors affecting transmission of pathogens
overcrowding living& working condiitons (1)
compromised immune system (2) - lack of nutrition/ immunosuppressants
socioeconomic e.g lack of trained workforce
direct transmission in plants defintiion
direct contact of healthy plant with any part of diseased plan
indirect transmission in plants defintiion
passing pathogen from host to new host via a vector e.g an insect attack
vectors for plants (4)
wind, water, animals, humans
how to prevent spread of communicable diseases in plants (3)
clear fields thoroghly during harvest
wash clothes & equipment
control insect vectors (3)
factos increasing trasmisionnsion of pathogens (3)
overcrowding of crops
poor mineral nutrition reduces plants resistance
damp warm conditions
passive defense meaning (plants)
A defense mechanism against pathogens(1) present before infection(2) includes physical and chemical barriers (3)
name structiral passive defenses
lignin, bark, cellulose cell wall, waxy cuticle, stomatal closure
lignin function in passive defense
thickening of cell wall, makes it waterproof & indigestible
waxy cuticle function in passive defense
prevents water collecting on cell surfaces so pathogens cant survive
stomatal closure function in passive defense
when pathogen dteceted, guard cells close stomata in that area of plant to prevent direct entry
what is the active chemical defence where large polysaccharides are deposited in sieve tubes
callose
callose function(3)
large polysaccharides are deposited in sieve tubes(1) to plock flow in phloem(2) & prevent pathiegn spread (3)
what is the active chemical defense where there’s balloon-like swelling blocking xylem
tylose
tylose function(4)
balloon-like swelling blocking xylem to prevent spread of pathogen (2)
contains terpenes which are chemical toxins to pathogens (4)
which active chemical defnse occurs in xylem
tylose
which active chemical defnse occurs in phloem
callose
Give 2 ways pathogens are detected by plants
1) pathigen detected by specific pathogens on cell surface
2) when cell wall of plant broken down by pathogens, cell wall breakdown products recognised
what happens after pathogen is detected by plant
signalling molecules alert nucleas & adjacent cells beofre attack
name 3 active responses initiated by plant after pathogen is detected
1) defensive molecules relased directly attack pathogen
2) polysaccharide strengthen cell wall
3) chemicals alarms other cells
name3 active defenses in plants
liginin reiforced (1)
callose and tylose fomred(2)
increase in chemicals formed
terpenoids functopn
essential oils have antifungal and antibacterial forms
necrosis defnition
dlibertate cell suicdee
point of necrosis
killing cells surrounding infection to limit pathogens
lesion definition
damaged tissue in a plant
canker definition
region of necrosin causing death of cambium tissue in bark preventing spread of pathogens
how does canker prevent spread of disease
limites pathogens access to water & nutriwns by surrounding infecion & stops its spread
why are most protectcive chemicals in plants manufactures when infection is detected
making defensive chemicals takes energy; plants saves energy by not making these until needed (2)
primary defnses definition
barriers which prevemts entry of pathogens
secondary defenses definition
combat pathogens that have entered the body
how is skin a primary defense mechanism (3)
- physical barrier
- frequently sloughs off to reduce chance of growth on surface
- produces sebum, antibiotic which inhibits growth of pathogens
mucous membrane definiton (2)
contaisn lysozymes to destroy bacterial and fungal cell wall
produced by goblet cells and wafted out by ciliated epithelium cells to enter oesophagus and digestive system
how is ear wax a primary defense mechanism (3)
lined by wax to trap pathogens
how is female reporductive system a primary defense mechanism (1)
mucus plug in cervix maintaisn acidic conditions of vagina
how are expulsive a primary defense mechanism (3)
- responds to irritation from toxins or microorganisms (1)
- in gas exchange system coughs and sneezes eject microorganism
- vomiting and diahorea expel contents of the gut along with infected pathogens
what are the 5 types of primary defenses in humans
skin, mucous membranes, ear wax, expulsive reflexes, lysosymes
inflammation definition
localised response to pathogens/damage resulting in swelling and redness at site of wound
how is inflammation response initiaed
damaged mast cells relase histamins an cytokines
histamines definition
enzyme that causes vasodilation (1), causing localised heat and rednesses to infection site for WBC’s to leave blood and enter tissue fluid = causes swellingand pain. Pathogens are drained into lymoh system to contact lymphocytes and initiate specficifc immune response
