communicable disease + biodiversity Flashcards
what are the primary non specific defences in animals against pathogens
- skin (has healthy mircroorganisms that outcompete pathogens for space, sebum and oily sub also inhibits growth of pathogens
- blood clotting
- wound repair
- inflammation
- expulsive reflexes like sneezing
- mucous membranes- traps pathogens and contains lysosomes and phagocytes
- lysosomes in tears and urine and stomach acid
what are the roles of cytokines
attract white blood cells/ phagocytes to site of infection
these act as cell signalling molecules informing other phagocytes that the body is under attack making them move to site of infection/ inflammation.
increase body temperature and stimulate the specific immune system
what are the roles of opsonins
chemicals that bind to pathogens
what are the roles of phagosomes and lysosomes
when a phagocyte has engulfed a pathogen the vacuole it encloses it in is called the phagosome
this will combine with lysosomes to form a phagolysosome where enzymes will digest and destroy the pathogen
what is the structure of phagocytes
specialised white blood cells that engulf and destroy pathogens
two types- neutrophils and macrophages
how do phagocytes work
they build up at the site of infection as they are attracted by chemicals produced by pathogen
- they recognise the pathogen as non-self and bind to it
- they then engulf to form phagosome
how is blood clotting a defence
blood clots seal the wound to stop pathogens getting in
when platelets come into contact with collagen in skin or wall of damaged blood vessel they ADHERE and secrete substances like thromboplastin and serotonin
collagen fibres deposited too to give new tissue strength. Once the epidermis reaches normal thickness the scab falls off
how is inflammation a defence
localised response to pathogens/ or irritants
characterised as pain, redness,swelling
activates MAST cells which release histamines and cytokines
what are neutrophils and what is their purpose in immune response
white blood cell with lobed nucleus to fit through tight places to get to site of infection
A type of immune cell that is one of the first cell types to travel to the site of an infection. Neutrophils help fight infection by ingesting microorganisms and releasing enzymes that kill the microorganisms. A neutrophil is a type of white blood cell, a type of granulocyte, and a type of phagocyte.
what is an antigen presenting cell and how is it made
and what is a MHC
macrophages take longer to engulf and destroy bacterium than neutrophils but it is more complex
when digested a pathogen, the macrophage combines antigens from pathogen surface membrane with special GLYCOPROTEINS in the cytoplasm called MHC or major histocompatability complex which moves these pathogens antigens to the macrophages own surface membrane to become an antigen presenting cell
what are thromboplastin and seretonin
> thromboplastin is an enzyme which triggers the blood clotting cascade to form a blood clot/ thrombus
(makes prothrombin becomes thrombin along with Ca2+ ions)
> serotonin makes smooth muscle walls of blood vessels contract so they narrow and reduce blood supply
what are histamines
secreted by mast cells,
they make blood vessels dilate causing localised redness and heat as inc. temp prevents pathogens reproducing
>they make blood vessels more leaky so blood plamsa forced out which makes tissue fluid which causes swelling and pain
what does thrombin catalyse
the reaction which makes fibrin from fibrinogen
what is the purpose of antigen presenting cells
stimulate other cells involved in the SPECIFIC immune system response
what is the structure and role of T helper cells
have CD4 receptors on their cell surface membranes which bind to the surface antigens of antigen presenting cells
-they produce interleukins
what is the structure and role of T killer cells
these destroy the pathogen carrying the antigen
> they produce the chemical perforin with kills pathogens by making holes in the surface membrane so it is freely permeable
what is the structure and role of T memory cells
live for a long time and are part of the IMMUNOLOGICAL MEMORY
if these meet an antigen a second time they divide rapidly to form clones of T killer cells and destroy pathogen
what is the structure and role of T regulator cells
supress the immune system
act to control and regulate it
they stop the immune response once a pathogen has been eliminated to make sure the body recognises self antigens and doesnt set up an autoimmune response
interleukins also important in this control
what is the structure and role of plasma cells
this produce antibodies for a particular antigen and release them into the circulation
an active plasma cell only lives for a few days but produces many antibodies a second while alive+active
what is the structure and role of B effector cells
these divide to form plasma cell clones
what is the structure and role of B memory cells
live for a VERY LONG TIME
provide immunological memory
remember a specific antigen and enable body to make a very rapid response when encountering a pathogen with that antigen again
what are interleukins
they are produced by T helper cells and are a type of cytokine
>they stimulate the activity of B cells which increases antibody production and production of other T cells
> also attract and stimulate macrophages to ingest pathogens with antigen -antibody complex
read this :)
an antiGEN GENerates an antibody
what is the difference between T and B lymphocytes
B are made in Bone marrow
T are made in the Thymus gland
What is the primary immune response
cloned plasma cells produce antibodies that fit antigens on surf. of pathogen and bind to antigen to disable them OR act as opsonins or agglutinins
this can take a few days or weeks
what is the secondary immune response
cloned B cells develop into B memory cells so if body infected by same antigen again, B memory cells divide rapidly to form plasma cell clones
these produce the right antibody quickly before symptoms show
what are agglutinins
how pathogens defend body
antibodies act as agglutinins causing pathigens with antigen-antibody complexes to clump together
this prevents them spreading through body and makes easier for phagocytes to engluf a number of pathogens at the same time
what is a antigen-anibody complex
it acts as an opsonin so complex is easily engulfed and digested by phagocytes
what are anti-toxins
antibodies can act as anti-toxins by binding to toxins produced by pathogens and making them harmless
what is the specific immune system
slower reacting than non
includes production of immune response with production of polypeptides called antibodies
which are specific to a pathogen
what is the non-specific immune system
defences that keep pathogens out
what is clonal selection
part of humoral immunity
>when activated T helper cells bind to the B cell antigen presenting cell. The B cell with the correct antibody for antigen is selected for CLONING
after this and before expansion, interleukins produced by T helper cells activate the B cells
what is clonal expansion
the activated B cells divide by mitosis and produce clones of plasma cells and B memory cells
after this there is the primary immune response and then secondary immune response
what are the 3 levels biodiversity can be measured at
habitat biodiversity
species biodiversity
genetic biodiveristy
what is habitat biodiversity
number of different habitats found within an area
»>each habitat can support a number of dif species
generally the greater the habitat biodiveristy the greater the species biodiveristy will be
what is species biodiversity
|»_space;>what is species richness and species eveness
made up of 2 components
species RICHNESS= number of DIFFERENT species living in a particular area
species EVENESS= a comparison of the numbers of INDIVIDUALS of each species living in a community
therefore areas can differ in species biodiversity even if it has the same number of species!
what is genetic biodivesity
variety of genes that make up a species eg) humans have 25,000 but some plants have 400,000
different alleles for same gene exist
can lead to different characteristics being shown such as breeds of dog and of these many alleles for things like coat colour/length
GREATER GENETIC BIODIVERSITY WITHIN A SPECIES ALLOWS BETTER ADAPTION TO CHANGES IN ENVIRONMENT AND DISEASE RESISTANCE
What is random sampling
means of selecting individuals by CHNACE
in this kind of sample all individuals have an equal likelihood of selection
what is non-random sampling and give examples
not chosen at random and includes techniques such as:
Opportunistic
Stratified
Systematic
what is opportunistic sampling
weakest form of sampling as not Representative of population as whole
uses organisms that are conveniently available
what is stratified sampling
some populations can be divided into strata/ sub groups based of characteristics
eg male and female
random sample is taken from each of these strata proportional to its size
what is systematic sampling
systematic sampling different areas within overall habitat are identified and sampled separately
>such as how species change as move inland
line transects used or belt transects
belt provide more information as samples taken from area between two lines
two ways reliability may vary
and how you can improve this
SAMPLING BIAS- may be deliberate or accidental to reduce, reduce human involvement
CHANCE- organsims may not be representitive of whole population and this can never be removed completely
can be minimised by using a larger sample size
what are pooters
catch small insects off trees
what are sweep nets used for
catching insects in tall grass
how would you sample small crawling invertebrates like beetle ect
pitfall trap
what is tree beating
take samples of invertebrates living in a tree or bush and tree shaken and anything falls onto cloth
what is kicksampling
study organisms in river
riverbed kicked for certain time period and net held downstream to catch any organisms released into flowing water
how can plants be sampled
with quadrat
either point quadrat or frame
how is density frequency and percentage cover measured with frame quadrat
Density- count number of one species per 1m by 1m quadrat (absolute measure not estimate)
frequency- when individs are hard to count like moss or grass so instead count how many squares that species is present in eg 65 squares have clover/100 then 65%
%cover- lots of data collected quickly for difficult to count data estmated with eye area within quadrat a plant species covers
MEANS SHOULD BE TAKEN WITH ALL
>TO WORK OUT POPULATION MULTIPLY MEAN VALUE PER M2 BY TOTAL AREA
what is a tullgren funnel
A Berlese funnel, also known as Tullgren funnel, Berlese trap, or Berlese-Tullgren funnel, is an apparatus used to extract living organisms, particularly arthropods, from samples of soil
how is species richness measured
use identification key
how is species eveness measured
comparing number of individuals in a species
what is N in simpsons index of diversity
total number of organisms of ALL species (richness)
what is the convention on international trade in endangered species
CITES - treaty that regulates the international trade of wild plants and animals and their products
35,000 species protected
what is the rio convention on biological diversity
CBD
requires countries to develop strategies for sustainable development
what is the countyside stewardship scheme
CSS
- sustaining beauty and diversity of landscape
- improving and extending and creating wildlife habitats
- restoring neglected land and conserving archaeological and historic features
- improving countryside enjoyment
