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A A A Level Biology > communicable disease + biodiversity > Flashcards

communicable disease + biodiversity Flashcards

(57 cards)

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1
Q

what are the primary non specific defences in animals against pathogens

A
  • 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
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2
Q

what are the roles of cytokines

A

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

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3
Q

what are the roles of opsonins

A

chemicals that bind to pathogens

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4
Q

what are the roles of phagosomes and lysosomes

A

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

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5
Q

what is the structure of phagocytes

A

specialised white blood cells that engulf and destroy pathogens

two types- neutrophils and macrophages

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6
Q

how do phagocytes work

A

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
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7
Q

how is blood clotting a defence

A

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

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8
Q

how is inflammation a defence

A

localised response to pathogens/ or irritants
characterised as pain, redness,swelling

activates MAST cells which release histamines and cytokines

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9
Q

what are neutrophils and what is their purpose in immune response

A

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.

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10
Q

what is an antigen presenting cell and how is it made

and what is a MHC

A

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

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11
Q

what are thromboplastin and seretonin

A

> 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

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12
Q

what are histamines

A

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

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13
Q

what does thrombin catalyse

A

the reaction which makes fibrin from fibrinogen

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14
Q

what is the purpose of antigen presenting cells

A

stimulate other cells involved in the SPECIFIC immune system response

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15
Q

what is the structure and role of T helper cells

A

have CD4 receptors on their cell surface membranes which bind to the surface antigens of antigen presenting cells

-they produce interleukins

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16
Q

what is the structure and role of T killer cells

A

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

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17
Q

what is the structure and role of T memory cells

A

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

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18
Q

what is the structure and role of T regulator cells

A

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

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19
Q

what is the structure and role of plasma cells

A

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

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20
Q

what is the structure and role of B effector cells

A

these divide to form plasma cell clones

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21
Q

what is the structure and role of B memory cells

A

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

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22
Q

what are interleukins

A

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

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23
Q

read this :)

Study These Flashcards
A

an antiGEN GENerates an antibody

24
Q

what is the difference between T and B lymphocytes

Study These Flashcards
A

B are made in Bone marrow

T are made in the Thymus gland

25
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
26
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
27
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
28
what is a antigen-anibody complex
it acts as an opsonin so complex is easily engulfed and digested by phagocytes
29
what are anti-toxins
antibodies can act as anti-toxins by binding to toxins produced by pathogens and making them harmless
30
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
31
what is the non-specific immune system
defences that keep pathogens out
32
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
33
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
34
what are the 3 levels biodiversity can be measured at
habitat biodiversity species biodiversity genetic biodiveristy
35
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
36
what is species biodiversity | >>>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!
37
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
38
What is random sampling
means of selecting individuals by CHNACE | in this kind of sample all individuals have an equal likelihood of selection
39
what is non-random sampling and give examples
not chosen at random and includes techniques such as: Opportunistic Stratified Systematic
40
what is opportunistic sampling
weakest form of sampling as not Representative of population as whole uses organisms that are conveniently available
41
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
42
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
43
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
44
what are pooters
catch small insects off trees
45
what are sweep nets used for
catching insects in tall grass
46
how would you sample small crawling invertebrates like beetle ect
pitfall trap
47
what is tree beating
take samples of invertebrates living in a tree or bush and tree shaken and anything falls onto cloth
48
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
49
how can plants be sampled
with quadrat either point quadrat or frame
50
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
51
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
52
how is species richness measured
use identification key
53
how is species eveness measured
comparing number of individuals in a species
54
what is N in simpsons index of diversity
total number of organisms of ALL species (richness)
55
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
56
what is the rio convention on biological diversity
CBD | requires countries to develop strategies for sustainable development
57
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

A A A Level Biology (22 decks)

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