disease lesson SLOP Flashcards

1
Q

State the kingdom of organism that causes each of the following diseases: tuberculosis, Black Sigatoka, Athlete’s foot, malaria

A

Bacteria, fungi, fungi, protoctists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

State the kingdom of organism that causes each of the following diseases: blight, ringworm, ring rot, bacterial meningitis

A

Protoctists, fungi, bacteria, bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give one plant disease caused by each of each following virus, bacteria and fungi

A

Tobacco mosaic virus, ring rot, black sigatoka

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

state how the influenza virus is most likely to be transmitted between different humans

A

Respiratory droplets (inhalation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

state four different types of vector that can be used to transmit a communicable disease

A

Water (e.g. diarrhoeal diseases); animals (e.g. mosquito transmits Plasmodium); wind (carries spores); humans (hands, clothing etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

State three physical defences that prevent plants being infected by a pathogen

A

passive Bark, waxy cuticle, thorns, spines, lignified cell walls, cellulose etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

state 3 active physical defences a plant would employ against an invading pathogen

A

Callose synthesised and deposited between plasma membrane and cell wall; callose blocks sieve plates in phloem; callose deposited in plasmodesmata between infected cells and their neighbours; lignin added to cell walls; tyloses block xylem vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

state 3 chemical defences a plant would employ against an invading pathogen

A

Antibacterial compounds like phenols, alkaloids; terpenes; hydrolytic enzymes like glucanases and chitinases; caffeine; tannins etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe the role of the skin as a primary non-specific defence

A

Dead outer layer of keratin prevents pathogen entry; skin flora outcompete pathogens for space; oil secretions inhibit pathogenic growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe the role of mucous membrane as a primary non specific defence

A

Mucus traps pathogens and contains lysozymes; phagocytes engulf and digest pathogens in mucus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

which enzyme catalysed the conversion of prothrombin to thrombin

A

Thromboplastin (thrombokinase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe the role of thrombin in the clotting process

A

Causes the conversion of soluble fibrinogen into insoluble fibrin fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe the process of inflammation as a secondary non-specific response

A

Mast cells release histamines; histamines increase permeability of capillaries meaning plasma leaks into tissue fluid (pain and swelling); vasodilation of arterioles so more blood reaches infected area (heat and redness); neutrophils attracted to area for enhanced phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

describe the process of phagocytosis

A

Phagocyte engulfs pathogen into a phagosome; lysosomes fuse with phagosome to form a phagolysosome; enzymes, hydrogen peroxide and nitric acid break down the pathogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe how macrophages process antigens for presentation on their cell surface membrane

A

Antigen fragments combined with MHC (special glycoproteins in cytoplasm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is name given to small protein molecules that act as cell-signalling compounds?

A

cytokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

describe how neutrophils are specialised for their role

A

contains receptors for opsonins, well developed cytoskeleton for phagocytosis, many mitochondria for respiration, many ribosomes to make enzymes, many lysosomes, many Golgi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

opsonins are non specific. explain why.

A

Opsonins can attach to many types of pathogen and help the process of phagocytosis, by giving the phagocyte something to bind to. They must be non-specific, so they can attach to many different pathogens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

where do B and T lymphocytes mature?

A

Bone marrow and thymus respectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is meant by the term ‘autoimmunity’ and give two examples of autoimmune diseases

A

Destruction of self-tissue; rheumatoid arthritis, lupus, type I diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the role of T regulatory cells

A

Dampen down the immune response; prevents destruction of self tissue (autoimmunity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

describe how an antigen presenting cell leads to large numbers of T helper cells

A

APC binds specifically to a Th cell (clonal selection). This selected Th cell then proliferates by mitosis (clonal expansion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

describe how b lymphocytes are activated and the role of activated B lymphocytes

A

The cell binds specifically to B lymphocyte; B lymphocyte differentiates into a plasma cell. Plasma cells release antibodies specific to the particular antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

describe how T killer cells destroy a virally infected cell

A

Release perforins which punch holes in the membrane of the cell; Tk cell inserts channels through which it floods hydrolytic enzymes

25
Q

distinguish clearly between an antigen and an antibody

A

An antigen is a cell-surface molecule that is specific to the cell (and a particular antibody); an antibody is an immunoglobulin manufactured by the plasma cells (which binds specifically to an antigen).

26
Q

antibodies are made by plasma cells. Explain how plasma cells are specialised for their role

A

Plasma cells have a lot of ribosomes, rough endoplasmic reticulum, Golgi apparatus and mitochondria.

27
Q

describe how opsonins function

A

Opsonins bind specifically to an antigen on a pathogen (via the variable region), clearly marking the pathogen for destruction by a neutrophil. A neutrophil will bind to the constant region of the opsonin and destroy the pathogen by phagocytosis

28
Q

describe how agglutinins function

A

Agglutinins cross link pathogens by binding specifically via their variable regions. Pathogens are clumped together (agglutinated), meaning they cannot enter host cells and are easier to phagocytose

29
Q

describe how antitoxins functions

A

Neutralise toxin molecules released by a pathogen through direct binding

30
Q

describe how the structure of an antibody enables it to preform its function

A

The variable region is specific to the antigen – it has a shape that is complementary to the shape of the antigen; the disulfide bridges hold the four polypeptide chains together; the hinge region allows some flexibility so that the molecule can bind to more than one antigen; the constant region may have a shape that can be recognised by the neutrophils.

31
Q

explain why it may take several days for primary immune response to become effective

A

After infection, the pathogen must be detected and attacked by macrophages; antigen presentation occurs to select the correct B and T cells (clonal selection); these cells must reproduce in clonal expansion; then they must differentiate to form plasma cells; the plasma cells must start to produce the antibodies – each step takes time.

32
Q

explain why a secondary immune response is so much faster than a primary immune response

A

B memory and T memory cells are circulating in the blood. On second encounter with a pathogen, the correct B/T memory cell is clonally selected and can very quickly differentiate into correct specific Th/Tk/plasma cell. Plasma cells can produce antibodies faster, sooner and in much greater quantity. Pathogens are wiped out before symptoms are experienced; level of antibody stays higher for longer

33
Q

give an example of both natural active immunity and natural passive immunity

A

Natural active - antibodies made by immune system in response to infection; natural passive - antibodies provided via placenta/breast milk (useful in developing immune system)

34
Q

explain why passive immunity only provides short term immunity

A

Passive immunity is provided by an external supply of antibodies – these are proteins and will not last long in the body. They may even act as antigens and be attacked by antibodies from our immune system.

35
Q

give an example of artificial active immunity

A

Immunity provided by antibodies made in response to vaccination (dead/inactive pathogens injected)

36
Q

define the term epidemic

A

A rapid spread of disease through a high proportion of a population (usually within a country)

37
Q

describe the difference between herd vaccination and ring vaccination

A

Herd vaccination is where everyone, or almost everyone, is vaccinated. Ring vaccination is vaccinating people around the site of the outbreak, so that the pathogen will not be transmitted across that ring to the whole population.

38
Q

describe how a microorganism can become resistant to an antibiotic

A

Bacteria that survive a treatment will be slightly resistant to the antibiotic and the antibiotic acts as a selective force which selects the resistant individuals. When they reproduce, some of their offspring may be more resistant, thus resistance evolves.

39
Q

what is indirect transmission

A

pathogen travels from one individual to another via an intermediate e.g. air, food , water

40
Q

definition of transmission

A

the passing of a pathogen from an infected individual to an uninfected individual

41
Q

gives examples of direct transmission in animals

A

skin to skin contact
contact with bodily fluids
animal bites
water droplets

42
Q

indirect transmission in animals

A

via vector (mosquito)
inanimate objects e.g. door handle
faecal-oral (contaminated food)
spores (fungal)

43
Q

factors that affect rate of transmission within a population

A

climate change (warmer climates)
economic development
poor health and diet
poor ventilation
human demographics
microbial adaptation (resistance)

44
Q

indirect transmission in plants

A

via vector
soil contamination
humans via hands, clothes during farming
water
spores

45
Q

why are plants useful hosts for pathogens

A
  • supply of carbohydrates, proteins and oils
  • plant support transmissions through seeds and fruit
46
Q

what is a sieve plate

A

allow stuff to travel between phloem

47
Q

what is cambium tissue

A

meristem part - where cell divides to form xylem or phloem

48
Q

examples of passive defences in plants

A
  • cellulose cell wall
  • lignin thickened cell wall
  • waxy cuticle
  • bark (tannins)
  • stomatal closure
  • callose (polysaccharide in phloem which is deposited at sieve plates prevents pathogen entry).
  • tylose (swellings in xylem - balloon like) can block xylem preventing pathogens spreading
49
Q

examples of active defence in plants against pathogens

A
  • more callose between cells
  • oxidative bursts (cells that have pathogens can be damaged)
  • increase hydrolytic enzymes + defenins
  • necrosis = deliberate cell suicide by intracellular enzymes forming brown spots
  • canker - sunken necrotic lesion in the woody tissues death of cambium tissue)
50
Q

what are terpenoids and give an example

A
  • range of essential oils that have antibacterial/fungal properties + have a scent
  • menthols
51
Q

what are phenols and give an example

A
  • antibiotic + anti-fungal properties
  • tannins = found in bark inhibit insect attack by binding to salivary proteins and digestive enzymes e.g. trypsin and deactivating them. Insects ingest high conc of phenols stop growing and die.
52
Q

what are alkaloids and give an example

A
  • nitrogen containing compound with bitter taste to inhibit herbivore feeding.
  • inhibit enzyme activity + protein synth.
  • nicotine, cocaine
53
Q

what are defensive proteins and give an example

A
  • small cysteine rich proteins with broad anti-microbacterial activity, inhibit transport channels
  • defensins
54
Q

what are hydrolytic enzymes

A
  • digest pathogens
  • lysosomes (bacterial cell wall), chitinases(fungi cell walls), glutanases (glycosidic bonds)
55
Q

main primary defence

A

skin - prevent pathogen from entering the body

56
Q

examples of primary defence

A
  • stomach acid
  • nose hair + eyelashes
  • inflammatory response (histamines)
  • mucous membranes (goblet + epithelial) = snot
  • sneezing, coughing, diarrhoea, vomiting
  • cilia in the lungs
  • blood clotting
57
Q

what is anticoagulant

A

prevents blood clotting

58
Q

what events take place during inflammation

A
  • mast cell produce histamine
  • vasodilation occurs
  • blood into infected area
  • capillary wall increase permeability to white BC and proteins
  • increase production of tissue fluid leads to swelling
  • excess tissue fluid drained into lymphatic system where lymphocytes are stored