Topic 3 - Infection and response Flashcards
(102 cards)
1
Q
What is a pathogen?
A
Pathogens are microorganisms that cause infectious disease
2
Q
How does bacteria make you feel ill?
A
the produce and release toxins that damage your cells and tissues
3
Q
Name 4 types of pathogens
A
- bacteria
- virus
- protist
- fungi
4
Q
How do viruses work?
A
Viruses live and reproduce inside cells, causing the cell to burst and release all the new viruses to other cells. the cell damage is what causes ill symtpoms
5
Q
Name 3 ways in which pathogens can be spread
A
- water
- air
- direct contact
6
Q
Name 3 viral diseases
A
- measles
- HIV
- Tobacco mosaic virus (TMV)
7
Q
What are the symptoms of measles?
A
- red skin rash
- high fever
8
Q
How serious is measles? and why?
A
Measles is a serious illness that can be fatal if complications arise. it can lead to pneumonia or inflammation of the brain
9
Q
What is the treatment for measles?
A
most people are vaccinated against it when they’re young/children
10
Q
How is the measles virus spread?
A
The measles virus is spread by inhalation of droplets from sneezes and coughs.
11
Q
How does HIV work and how do symptoms change during the different stages?
A
Initially Hiv causes flu- like symptoms.
Unless successfully controlled with antiretroviral drugs the virus attacks the body’s immune cells
when the body’s immune system is badly damaged, it cant cope with other infections or cacers. This stage is known as late stage HIV infection, or AIDS.
12
Q
How is HIV viru spread?
A
sexual contact
exchanging bodily fluids (sharing needles)
13
Q
What are the symptoms of TMV?
A
mosaic pattern on leaves of plamts
discoloration on leaves
14
Q
How does TMV affect the plant?
A
the discoloration it causes means that the plant cant carry out photosynthesis as well so the virus affects its growth
15
Q
Is rose black spot a virus, bacteria, fungi or protist
A
fungi
16
Q
What organism does rose black spot affect?
A
rose plants
17
Q
what are the symptoms of rose black spot and how does it affect the plant?
A
- purple or black spots develop on leaves which can then cause the leaves to turn yellow and drop off
- this means that less photosynthesis can occur (because there are less leaves to absorb light for photosynthesis) and the plant wont grow very well
18
Q
How is rose black spot spread?
A
Through the environment:
- water (wet conditions allow the fungi to build up)
- the wind (carry spores to next plant)
19
Q
How can rose black spot be treated? (2 ways)
A
- fungicides
- remove infected leaves from plant (to stop spreading to other parts of the plant) and destroy the leaves so the fungus cant spread to other plants
20
Q
Is malaria a fungi, virus, protist or bacteria
A
it is caused by a protist
21
Q
How does malaria work and how is it spread?
A
part of the malarial protists life cycle takes place inside the mosquito (vector). the mosquito picks up the malarial protist when feeding on an infected animal. it then transfers it to other animals (infecting them) when it feeds on them by inserting it into the animals blood vessels.
22
Q
symptoms of malaria?
A
- repeating episodes of fever
- headaches
- can be fatal
23
Q
How can the spread of malaria be reduced? (3 ways)
A
- stop mosquitos from breeding
- using insecticides
- mosquito nets
24
Q
Are protists eukaryotes or prokaryotes?
A
eukaryotes
25
True or false:
Most protists are single-celled
true
26
Give an example of a protist
parasites
27
give an example of a disease caused by a protist
malaria
28
How are protists often spread?
a vector
29
True or false:
All fungi are single- celled
false - some are single-celled others have a body which is made up of hyphae (thread-like structure)
30
What is a hyphae and how does it cause disease?
1. thread like substance made up of multicellular fungi
2.they can grow and penetrate human skin and the surface of plants causing disease
3. they can also produce spores which can be spread to other plants and animals
31
Is salmonella a fungal viral protist or bacterial disease?
bacterial disease
32
Is salmonella a fungal viral protist or bacterial disease?
bacterial disease
33
What does salmonella cause?
food poisoning
34
What does salmonella cause?
food poisoning
35
What are the symptoms of salmonella?
Fever,stomach cramps,vomiting,diarrhoea
36
what are the symptoms of salmonella caused by?
toxins that the bacteria releases
37
how do you get salmonella food poisoning ?
eating food that has been contaminated with the bacteria e.g. eating chicken that caught the disease whilst it was alive.
38
how is the spread of salmonella controlled in the uk
most poultry are given a vaccination against it .
39
how is gonorrhoea transmitted
sexually transmitted
40
is gonorrhoea a viral, bacterial or fungal disease
bacterial
41
what are the symptoms of gonorrhoea?
pain when urinating
thick yellow or green discharge
42
How can the spread of gonorrhoea be prevented
antibiotics
barrier methods of contraception
43
what are the 4 different ways of reducing and preventing the spread of disease?
being hygenic- washing hands
destroying vectors- using insecticides or destroying their habitats
isolating infected individuals
vaccination
44
Describe 4 features of the human body that prevent pathogens from entering and causing harm
the skin - acts as a barrier and secretes antimicrobial substances which kill them.
hair and mucus in nose- trap particles that could contain pathogens
trachea and bronchi - secrete mucus to trap pathogens, lined with cilia to waft the mucus up to the back of the throat where it can be swallowed
stomach- produces hydrochloric acid which kills the pathogens
45
What is the function of a white blood cell?
helps protect against pathogens
46
Name 3 ways your white blood cells protect you against pathogens
1. Phagocytosis
2. Producing antibodies
3. Produce antitoxins
47
Explain phagocytosis
This is when white blood cells engulf foreign cells (or pathogens) and digest them
48
Describe how white blood cells produce antibodies to protect from pathogens
1. every pathogen has unique antigens on its surface
2. when white blood cells (lymphocytes) detect a foreign antigen they produce antibodies specific to the antigens detected, The antibodies cause pathogens to stick together and make it easier for phagocytes to engulf them.
3. Antibodies are produced rapidly and carried around the body to destroy all similar pathogens
4. if a person is infected with the same pathogen again, the lymphocytes will rapidly produce these antibodies to kill it (this means the person is immune to that pathogen)
49
Describe how antitoxins protect against pathogens
they are produced by lymphocytes and they neutralise (counteract) toxins produced by invading bacteria
50
Describe how vaccines work to protect from future infections
1. vaccinations involve injecting a small dosage of dead or inactive pathogens into the bloodstream
2. when white blood cells in the body detect the antigens on these pathogens, they produce antibodies to attack them (even though the pathogen is harmlesss)
3. This means that if you are infected with live pathogens after the vaccination, the white blood cells can rapidly mass- produce antibodies to kill the pathogen quickly. (this is called immunity)
51
Name 2 pros of vaccination
1. have helped control many communicable diseases that were once common in the uk (polio, measles, rubella, mumps, tetanus) smallpox no longer occurs at all, polio infections have fallen by 95%
2. epidemics (large outbreaks of disease) can be prevented if a large percentage of the population is vaccinated. This is because even people who arent vaccinated are unlikely to catch the disease because there are fewer poeple to pass it on
52
Name 2 cons of vaccinations
1. they dont always work/ give you immunity
2. you could have a bad reaction to the vaccine (swelling, fever, seizure) these are very rare
53
What do painkillers do?
drugs that realieve symptoms but do not kill pathogens
54
What do antibiotics do?
they kill (or prevent the growth of ) bacteria without killing your own body cells. different antibiotics kill different types of bacteria
55
Can antibiotics kill virusis?why?
antibiotics can kill bacteria but not viruses because they reproduce using your body cells .
56
What makes it difficult to develop drugs that destroy viruses?
viruses reproduce using your body cells which makes it hard to create drugs that destroy just the virus and not the body cells aswell
57
True or false:
bacteria can become resistant to antibiotics
True
58
What causes bacteria to become resistant to antibiotics?
random mutations
59
What would happen if you treated an infection with antibiotics but some of the bacteria were resistant?
only the non- resistant strains of bacteria would be killed.
The resistant bacteria wil survive and reproduce and the population of the resistant strain will increase (this is an example of natural selection)
60
What can resistant strains of bacteria lead to?
serious infection that cant be treated with antibiotics For example MRSA
61
what does MRSA stand for, what does it cause and what is it resitant to?
Meticillin- resistant staphylococcus aureus
causes serious wound infections that is resistant to most antibiotics even the strongest one (meticillin)
62
How can you slow down the rate of development of resistant strains? (2 ways)
1.doctors should avoid over-prescribing antibiotics (prescribing them for minor infections)
2. finish the whole course of antibiotics dont stop taking them just because you feel better
63
What is aspirin used for
used as a painkiller and to lower fever
64
What plant is aspirin from?
developed from a chemical found in willow
65
What is digitalis used to treat?
heart conditions (it increases heart rate and stimulates heart muscles)
66
From what plant was digitalis developed?
foxgloves
67
How was penicillin discovered and who discovered it?
alexander flemin
he found mould growing on one of his petri dishes containing staphylococus bacteria and noticed that the areas around the mould was free of bacteria. This lead to his dicovery that the mould on the petri dish was producing a substance that killed the bacteria (this substance was penicillin)
68
What does a lack of nitrates cause in plants and why ?
stunted growth because nitrates are needed to make proteins used for growth
69
What does a lack of magnesium ions do to plants? and why?
chlorosis
yellow leaves
because mineral ions are needed for making chlorophyll which is used for photosynthesis
70
Name 6 signs of disease in a plant
1. stunted growth
2. spots on leaves
3. patches of decay (rot)
4. abnormal growths (lumps)
5. malformed stems or leaves
6. discoloration
71
How can different plant diseases be identified? (3 ways)
1. look up the signs in a gardening manual or on a gardening website
2. taking the infected plant to a laboratory where scientists can identify the pathogen
3. using testing kits that identify the pathogen using monoclonal antibodies
72
Name and explain 3 physical defenses of plants against pathogens
1. waxy cuticle - provides a barrier to stop pathogens from entering
2. cell wall made of cellulose - form a physical barrier against pathogens that make it past the waxy cuticle
3. layers of dead cells around stems (for example bark)- barrier to stop pathogens entering
73
Name and explain 2 chemical defenses of plants
1. some produce antibacterial chemicals - these kill bacteria ( for example mint plant and witch hazel)
2. some plants produce poison - deter herbivores (e.g tobacco plants, foxgloves deadly nightshade)
74
Name and explain 3 mechanical defences of plants
1. thorns ans hairs - stop animals touching and eating them
2. leaves that droop or curl when something touches it - prevent themselves from being eaten by knocking of insects and move away from things
3. mimic other organisms- (e.g passion flower looks like butterfly eggs and stops butterflies laying their eggs there)
75
What 3 things are new drugs tested for?
1. dosage
2. toxicity
3. efficacy
76
Name and explain the 4 stages of drug testing
1. test on human cells and tissue(preclinical trials)
2. test on live animals
3. test on healthy volunteers (clinical trials)
4. test on sick patients
77
Why cant you test for drugs only on human cells and tissue?
you wont be able to test how the drug works on the whole or multiple body systems (e.g testing a drug for blood pressure must be done on a whole animal because it has an intact circulatory system)
78
Why are drugs tested on live animals
to test for efficacy, dosage and toxicity
79
What does the law in britain state about testing drugs on live animals and why?
any new drug must be tested on two different live mammals to make sure it is safe to be given to humans
80
Why are new drugs tested first on healthy volunteers?
to make sure it doesnt have any harmful side effects when the body is working normally
81
What does testing new drugs on humans help us find (abt the drug)?
optimum dose
82
How can doctors test how well a new drug works on patients? and why is this effective?
split patients randomley into two groups.
One group is given the new drug and the other is given a placebo.
this is so that the doctor can see and compare the actual difference the drug makes (this allows for the placebo affect)
83
What is the placebo effect?
when the patient feels the treatment is working and feels better even though they have been given the placebo and the treatment isnt doing anything
84
What is a placebo used for?
used in clinical trials to compare the results of the experimental drug with a control group
85
What is a placebo?
a substance that appears to be like the drug being tested but it actually isnt (and doesnt have any effects)
86
What is a double- blind trial?
neither the patient nor the doctor knows who has recieved the drug or the placebo until all the results have been gathered
87
Why are double- blind trials done?
so the doctors monitering and analysing the patients results arent subconsciously influenced by their knowledge
88
Why are the results of drug testing and drug trials not published until they've been through peer review?
to prevent false claims
89
What type of white blood cells produce antibodies?
B- lymphocytes
90
What are monoclonal antibodies produced from? and what does this mean?
lots of clones of a single white blood cell this means that all the antibodies are identical and will only target one specific antigen
91
Why is it difficult to produce lots of clones of lymphocytes?
lymphocytes dont divide easily
92
What is the name of the cell created by fusing a mouse B- lymphocyte with a tumor cell?
hybridoma
93
Why are tumor cells fused with b-lymphocite to create the hybridoma?
tumor cells dont produce antibodies but they divide very quickly
94
What are hybridoma cells used for?
they are cloned to obtain lots of identical cells which produce monoclonal antibodies. these antibodies are then collected and purified
95
Why are monoclonal antibodies useful?
they can be created to bind to any specific antigen. they will only bind to (target) molecules with the specific desired antigen in the body
96
Explain how monoclonal antibodies are used in pregnancy tests
1. A hormone called HCG is found in the urine of women only when they are pregnant (this is what pregnancy test sticks detect)
2. the part of the stick you pee on has antibodies to the hormone attached to blue beads.
3. more antibodies to the hormone are also stuck on the test strip (so they cant move)
4. if you are pregnant and you pee on the stick:
- the hormone will bind to the antibodies on the blue beads
- the urine moves up the stick carrying the hormone and the beads
- the beads and hormone bind tothe antibodies on the strip
- so the blue beads get stuck on the strip turning it blue
5. if you are not pregnant:
- the urine still moves up the stick carrying the blue beads but there are no hormones to stick the blue beads onto the test strip so it doesnt turn blue
97
How can monoclonal antibodies be used to treat cancer without damaging normal body cells?
1.cancer cells have tumour markers on their cell membranes. these sntigens arent found on normal body cells.
2. you can make monoclonal antibodies in the lab that bind to these tumor markers
3. an anti-cancer drug (radioactive substance, toxic drug or chemical which stops cancer cells growing and dividing) can be attatched to these monoclonal antibodies
4. the antibodies are given to a patient through a drip
5. the antibodies target the specific cells (cancer cells) because they only bind to the tumor markers
6. the drug kills the cancer cells but doesnt kill any normal body cells
98
What can monoclonal antibodies be used to do in labs for research and discovery? (3 things)
1. bind to hormones and other chemicals in blood to measure their levels
2. test blood sample in labs for certain pathogens
3. locate specific molecules on a cell or in a tissue
99
How can monoclonal antibodies be used to locate specific molecules on a cell or in a tissue? (3 steps)
1. monoclonal antibodies that will bind to the specific molecule your looking for are made
2. the antibodies are bound to a flourescent dye
3. if the molecules are present in the sample your analysing, the monoclonal antibodies will attach to them, and they can be detected using the dye
100
What is an advantage of monoclonal antibodies?
in cancer treatment unlike chemotherapy and radiotherapy, monoclonal antibodies only target specific cells meaning that less body cells are damaged and the side effects of an antibody based drug is lower than chemotherapy or radiotherapy.
101
What is an advantage of monoclonal antibodies?
in cancer treatment unlike chemotherapy and radiotherapy, monoclonal antibodies only target specific cells meaning that less body cells are damaged and the side effects of an antibody based drug is lower than chemotherapy or radiotherapy.
102
what is a disadvantage of using monoclonal antibodies?
they cause more side effects than were originally expected.
some are quite serious for example fever, vomiting, low or high blood pressure
this means that they are not as widely used as treatments as scientists had originally thought they might be
