Immunity and communicable diseases Flashcards
define what a pathogen is
a microorganism which can cause a disease
what are the 4 categories of pathogens
bacteria
fungi
protoctisca
viruses
give 3 characteristics of bacteria
genetic material is not found in a membrane bound nucleus it is found in cytoplasm
no membrane bound organelles
The cell wall is made up of peptidoglycan
what are toxins
chemicals which damage the host cells and tissues
give 3 characteristics of viruses
non-living
cannot reproduce outside of a host cell
genetic material is wrapped in a protein structure called capsid
define an antibiotic
a compound that kills or inhibits the growth of bacteria
how do viruses cause a viral infection
viruses invade the living cell
genetic material of the virus takes over the biochemistry of the host cell to make more viruses
reproduce very fast
evolve by by developing adaptations to their host cell
what type of organism are fungi
eukrayotic
how do fungi obtain nutrients
they digest their food extracellularily
release enzymes and digest the material around them
this causes damage to the host cell’s tissues
what is released when fungi reproduce
spores
what causes fungi diseases to spread quickly
spores
how does fungi affect plants
they attack the leaves
this reduces the rate of photosynthesis
this kills the plant
this reduces the crop yield
give 3 characteristics of protists
they use hosts
they may need a vector to transport it to the host
they can enter the body through polluted water
how do protists attack and damage the host’s tissues
they take over cells
break them open once the new generation starts to merge
they don’t take over the genetic material of a cell
they digest and use the the cell components as they reproduce
how do fungi attack and damage the host’s tissues
digest living cells and destroy them
how do toxins cause damage to the host
they poison or damage the host such as breaking down the cell membrane, some damage or inactivating enzymes and some interfere with the cell hosts’ genetic material,
what pathogen causes ring rot
bacteria
what does ring rot damage
leaves, tubers, fruit
what pathogen is tobacco mosaic virus
virus
what does TMV damage
leaves
flowers
fruits
what pathogen causes TB
bacteria
what damage does TB do
it damages and destroys lung tissue and supresses the immune system
is there a cure for TB, if so what is it?
antibiotics
how is TB prevented
improving living standards and vaccinations
what damage does bacterial meningitis do
a bacterial infection on the protective surfaces on the brain which can spread to the rest of the body and causes blood poising and rapid death
if there is a cure for bacterial meningitis what is it
antibiotics
what prevents bacterial meningitis
vaccines
what is influenza
viral infection of the ciliated epithelium, it kills them, leaving airways open to secondary infection
how is malaria transported into the human
the parasite reproduces inside the female mosquito
the female needs to take two blood meals for the protein to lay eggs
the parasite invades the human
it invades the red blood cells, liver and brain
give 5 factors affecting the transmission of communicable diseases in animals
over-crowding
poor nutrition
a compromised immune system
culture
climate change
give 3 ways that pathogens can be transmitted in plants
vectors
wind
water
give 5 factors affecting the transmission of communicable diseases in animals
planting varieties of crops that are susceptible to diseases
overcrowding
poor mineral nutrition reduces resistance of plants
damp, warm conditions increase the survival and spread of pathogens
climate change
are plants passive or active
active
what is meant by active and passive immunity
active immunity is made by the organism themselves
passive immunity is through the use of medication and antibiotics
describe how plants recognise an attack
receptors in the cells respond to the molecules from the pathogens or to the chemicals that damage the plant cell wall
stimulates the release of signalling molecules that appear to switch on genes in the nucleus
this triggers cellular responses
give 3 examples of cellular responses from plants
defensive chemicals
sending alarm signals to unaffected cells
physically strengthening the cell walls
give an example of a physical defence by plants
they produce high levels of the polysaccharide called callose (can act as barriers and block sieve pores in phloem)
give 3 examples of chemical defences by plants
insect repellents (e.g. pine resin)
antibacterial compounds
general toxins
