Topic 3- Infection and Response Flashcards
(219 cards)
1
Q
What are pathogens?
A
Pathogens are microorganisms that enter the body and cause disease.
2
Q
What do pathogens (microorganisms) cause?
A
They cause communicable (infectious) diseases.
3
Q
What are communicable diseases?
A
They are diseases that can easily spread.
4
Q
What are bacteria?
A
Bacteria are very small (about 1/100th size of your body cell), which can reproduce rapidly inside your body.
5
Q
What effect does bacteria have on your body?
A
They can make you feel ill by producing toxins (poisons) that damage your cells and tissues.
6
Q
What are viruses?
A
Viruses are not cells. They’re tiny about 1/100th the size of a bacterium. They can reproduce rapidly inside your body.
7
Q
What do viruses do inside your cell?
A
They live inside your cell and replicate themselves.
8
Q
How do viruses replicate themselves?
A
They do this by using the cell’s machinery to produce many copies of themselves.
9
Q
What happens after the virus replicate themselves within your cells?
A
The cell will usually then burst, releasing all the new viruses. This cell damage is what makes you feel ill.
10
Q
What are protists like?
A
They’re all eukaryotes and most of them are single-celled. Some protists are parasites.
11
Q
What are parasites?
A
Parasites live on or inside other organisms and can cause them damage.
12
Q
How are protists transferred to an organism?
A
By a vector, which doesn’t get the disease itself.
13
Q
Give an example of a vector that carries a protist.
A
An insect
14
Q
What are fungi like?
A
Some fungi are single-celled. Other have a body which is made up of hyphae.
15
Q
What are hyphae?
A
They are thread-like structures.
16
Q
How do hyphae cause diseases?
A
These hyphae can grow and penetrate human skin and the surface of plants, causing diseases.
17
Q
What can hyphae produce?
A
They can produce spores, which can be spread to other plants and animals.
18
Q
Which organisms can be infected by pathogens?
A
- Plants
2. Animals
19
Q
Give 3 ways in which pathogens are spread.
A
- Water
- Air
- Direct contact
20
Q
How can a pathogen be spread through water?
A
Some pathogens can be picked up by drinking or bathing in dirty water.
21
Q
How can a pathogen be spread through air?
A
Pathogens can be carried in the air and can then be breathed in.
22
Q
How can a pathogen be spread through direct contact? (1)
A
Some pathogens can be picked up by touching contaminated surfaces, including the skin.
23
Q
Give an example of how water can spread pathogens.
A
By cholera
24
Q
How are airborne pathogens carried in the air?
A
They are carried in the air in droplets produced when you cough or sneeze.
25
Give an example of how air can spread pathogens.
The influenza virus that causes flu is spread through air.
26
How can pathogens be spread through direct contact? (2)
It's most commonly spread by touching the same things as an infected person, e.g. shower floors and towels.
27
What are measles?
It is a viral disease. It is spread by droplets from an infected person's sneeze or cough.
28
What do people with measles develop?
1. Red skin rash
| 2. They'll show signs of a fever (high temperature).
29
What are the 2 infections measles can cause?
1. Pneumonia (lung infection)
| 2. Encephalitis (brain infection)
30
What do most people do to prevent themselves from having measles?
Most people are vaccinated against measles when they're young.
31
What is HIV?
HIV is a virus spread by sexual contact, or by exchanging bodily fluids such as blood.
32
When do people exchange bodily fluids?
When people share needles when taking drugs.
33
What does HIV initially cause?
It causes flu-like symptoms for a few weeks.
34
How can HIV be controlled?
It can be controlled with antiretroviral drugs.
35
What do antiretroviral drugs do?
These drugs stop the virus replicating in the body.
36
What does HIV attack in the body?
The immune cells.
37
What happens if the body's immune system is badly damaged?
It can't cope with other infections or cancers.
38
What is the name of the stage, when your body can't cope with other infections or cancers?
The virus is known as late stage HIV infection, or AIDS.
39
What is tobacco mosaic virus (TMV)?
It is a virus that affects many species of plants, e.g. tomatoes.
40
What does TMV cause?
It causes a mosaic pattern on the leaves of the plants- parts of the leaves become discoloured.
41
What does the discolouration of the leaves mean?
It means the plant can't carry out photosynthesis as well, so the virus affects growth.
42
What is the rose black spot?
It is a fungus that causes purple or black spots to develop in the leaves of rose plants.
43
What does the rose black spot do to leaves?
It turns the leaves to leave and the leaves drop off.
44
What happens if the leaves turn yellow and drop off?
Less photosynthesis can happen, so the plant doesn't grow very well.
45
How is the rose black spot spread?
It spreads through the environment in water or by the wind.
46
How do gardeners treat the rose black spot?
1. They may use fungicides
| 2. Or they strip the plant of its affected leaves
47
How can you prevent the spread of the rose black spot?
By destroying the affected leaves.
48
What is malaria caused by?
By a protist
49
Where does the life cycle of malarial protists take place in?
Inside the mosquito
50
What are mosquitos?
They are vectors.
51
What do mosquitos do?
They pick up the malarial protist when they feed on an infected animal.
52
What happens when a mosquito feeds on another animal?
It infects it by inserting the protist into the animal's blood vessels.
53
What does malaria cause?
It causes repeating episodes of fever. It can be fatal.
54
How can the spread of malaria be reduced?
By stopping the mosquitos from breeding.
55
How can people be protected by mosquitos?
By using:
1. Insecticides
2. Mosquito nets
56
Give 2 bacterial diseases.
1. Salmonella
| 2. Gonorrhoea
57
What is salmonella?
Salmonella is a type of bacteria that causes food poisoning.
58
What are the symptoms of salmonella?
1. Fever
2. Stomach cramps
3. Vomiting
4. Diarrhoea
59
What are the symptoms of salmonella caused by?
Toxins that the bacteria produce.
60
How can you get salmonella food poisoning?
By eating food that's been contaminated with Salmonella bacteria.
61
Give 2 example of how you can get salmonella food poisoning.
1. Eating chicken that caught the disease whilst alive.
| 2. Eating food that has been contaminated by being prepared in unhygienic conditions.
62
What is gonorrhoea?
It is a sexually transmitted disease (STD).
63
How are STDs passed on?
By sexual contact, e.g. having unprotected sex.
64
What is gonorrhoea caused by?
It is caused by bacteria.
65
Give 2 symptoms of gonorrhoea.
1. They will get pain when urinating
| 2. Thick yellow or green discharge from the vagina or the penis
66
How was gonorrhoea originally treated?
They were originally treated with an antibiotic called penicillin.
67
What is the problem with using penicillin against gonorrhoea now?
Strains of the bacteria have become resistant to it.
68
Give 2 ways in which you can prevent the spread of gonorrhoea?
1. People can be treated with antibiotics
| 2. Barrier methods of contraception, such as condoms.
69
Give 4 ways in which you can prevent the spread of disease.
1. Being hygienic
2. Destroying vectors
3. Isolating infected individuals
4. Vaccination
70
How can being hygienic prevent the spread of disease?
By using simple hygiene measures can prevent the spread of disease.
71
Give 2 circumstances in which you need to wash your hands the spread of disease.
1. Washing your hands thoroughly before preparing food
| 2. Or by washing your hands after you've sneezed, this can stop you infecting another person.
72
How can you prevent the spread of disease through organisms?
By getting rid of the organisms that spread disease.
73
How can you kill vectors?
1. Using insecticides
| 2. Destroying their habitat so that they can no longer breed.
74
How can you prevent the spread of disease if someone already has it?
By isolating the person with the communicable disease.
75
How can vaccinating people or animals stop the spread of diseases?
The vaccination helps them not develop the infection and then pass it on to someone else.
76
How does skin stop pathogens from entering the body?
The skin acts as a barrier to pathogens. It also secreted antimicrobial substances which kill pathogens.
77
How does the nose stop pathogens from entering the body?
Hairs and mucus in your nose trap particles that could contain pathogens.
78
How does the trachea and bronchi stop pathogens from entering the body?
The trachea and bronchi secrete mucus to trap pathogens.
79
What is the trachea and bronchi lined with?
Cilia
80
What is the cilia?
These are hair-like structures, which waft the mucus up to the back of the throat where it can be swallowed.
81
How does the stomach stop pathogens from entering the body?
It produces hydrochloric acid. This kills pathogens that make it that far from the mouth.
82
What is the most important part of the immune system?
It is the white blood cells.
83
What 3 things do the white blood cells do when they encounter a pathogen?
1. Consume them
2. Produce antibodies
3. Produce antitoxins
84
What is phagocytosis?
It is when the white blood cells can engulf foreign cells and digest them.
85
What unique molecules does invading pathogens have?
Antigens
86
What does the white blood cell do when it encounters a foreign antigen?
They will start to produce proteins called antibodies to lock onto the invading cells so that they can be found and destroyed by other white blood cells.
87
What is special about the antibodies produced?
The antibodies produced are specific to that type of antigen- they won't lock on to any others.
88
What is the name of white blood cells that produce antibodies?
B-lymphocytes
89
What happens after the white blood cells produce antibodies?
Antibodies are then produced rapidly and carried around the body to find all similar bacteria or viruses.
90
What happens if the person is infected with the same pathogen again?
The white blood cells will rapidly produce the antibodies to kill it- the person is naturally immune to that pathogen and won't get ill.
91
What is the function of antitoxins?
These counteract toxins produced by the invading bacteria.
92
What does vaccination involve?
Injecting small amounts of dead inactive pathogens.
93
In vaccinations, what do these dead or inactive pathogens carry?
These carry antigens.
94
What does the antigens within the inactive pathogens cause?
It cause your body to produce antibodies to attack them- even though the pathogen is harmless.
95
Give 1 example of a vaccine.
1. the MMR vaccine
96
What does the MMR vaccine contain?
It contains weakened versions of the viruses that cause measles, mumps and rubella (German vaccine) all in one vaccine.
97
What happens if live pathogens of the same type appear after the vaccination?
The white blood cells can rapidly mass-produce antibodies to kill of the pathogen.
98
Give a pro on vaccinations (1).
Vaccines have helped control lots of communicable diseases that were once common in the UK.
99
What 2 communicable diseases stopped because of vaccination?
1. Smallpox no longer occurs at all
| 2. Polio infections have fallen by 99%
100
Define epidemics.
Big outbreaks of disease.
101
How can an epidemic be prevented?
If a large percentage of the population is vaccinated.
102
What happens to those who are not vaccinated in the epidemic?
They are still unlikely to catch the disease because there are fewer people able to pass it on.
103
What happens if a not many people are vaccinated?
The disease can spread through them and lots of people will be ill at the same time.
104
Give a con on vaccination (1).
Vaccines don't always work- sometimes they don't give you immunity.
105
Give a con on vaccination (2).
You can sometimes have a bad reaction to a vaccine. But bad reactions are very rare.
106
Give 3 examples of the bad reactions you may experience from a vaccine.
1. Swelling
2. Fever
3. Seizures
107
What are painkillers?
They are drugs that relieve the pain.
108
What do painkillers not do?
They don't tackle the cause of the disease of kill pathogens.
109
What do painkillers do?
They just help reduce symptoms.
110
What are antibiotics?
They kill (or prevent the growth of) the bacteria causing the problem without killing your own body cells.
111
What has the use of antibiotics reduced?
The number of deaths from communicable diseases caused by bacteria.
112
What are bacteria able to do?
Mutate
113
What are bacteria able to do?
Mutate
114
How can a bacteria not get killed by an antibiotic?
Sometimes the mutations cause them to be resistant to an antibiotic.
115
What will the resistant bacteria do after treatment?
The individual resistant bacteria will survive and reproduce, and the population of the restraint strain will increase.
116
What can a resistant strain of bacteria cause?
A serious infection that can't be treated by antibiotics.
117
Give an example of a bacteria resistant to antibiotics.
MRSA (methicillin-resistant Staphylococcus aureus)
118
What does MRSA cause?
Serious wound infections and is resistant to the powerful antibiotic methicillin.
119
How can you slow down the rate of development of resistant strains?
Avoid over-prescribing antibiotics.
120
What do you need to do if antibiotics?
Finish the whole course of antibiotics and don't just stop once you feel better.
121
What do plants produce?
A variety of chemicals to defend themselves against pests and pathogens.
122
What can the chemicals produced by the plants be used for?
Drugs to treat human diseases or relieve symptoms.
123
How were a lot of our current medicines discovered?
By studying plants used in traditional cures.
124
What is aspirin used as?
Painkiller to lower fever.
125
How was aspirin developed?
It was developed from a chemical found in willow.
126
What is digitalis used for?
To treat heart conditions.
127
How was digitalis developed?
It was developed from a chemical found in foxgloves
128
What did Alex Fleming notice when he was clearing out some Petri dishes containing bacteria?
He noticed that one of the dishes of bacteria also had mould on it and the area around the mould was free of the bacteria.
129
What did Alex Fleming find out about the mould on the Petri dish?
It was producing a substance that killed the bacteria- this substance was penicillin.
130
How are drugs made?
They are made on a large scale in the pharmaceutical industry.
131
How does the process of making drugs start?
It starts with a chemical extracted from a plant.
132
What happens in preclinical testing? (1)
Drugs are tested on human cells and tissues in the lab.
133
What can you not do in preclinical testing? (2)
You can't use human cells and tissues to test drugs that affect whole or multiple body systems.
134
In preclinical testing what do you test the drugs on? (3)
Live animals
135
Give 3 reasons why drugs are tested on live animals in preclinical testing. (4)
1. Efficacy
2. Toxicity
3. Dosage
136
What is efficacy?
It is whether the drug works and produces the effect you're looking for.
137
What is toxicity?
It is how harmful it is.
138
What is dosage?
The concentration that should be given, and how often it should be given.
139
What happens after the drug passes the tests on animals? (5)
It's then testes on human volunteers in a clinical trails.
140
Why are the drugs tested on healthy volunteers? (6)
To ensure it doesn't have any harmful side effects when the body is working normally.
141
What happens at the start of the trial? (7)
A very low does of the drug is given and this is gradually increased.
142
What happens if the results of the tests on healthy volunteers are good? (8)
The drugs can be tested on people suffering from illness.
143
What is the optimum dose?
It is the dose of drug that is the most effective and has few side effects.
144
How do they test how well the drug works? (9)
Patients are randomly put into two groups.
145
What are both groups given? (10)
One is given the new drug, the other is given a placebo.
146
What is a placebo?
It is a substance that's like the drug being tested but doesn't do anything.
147
Why do they give 2 different things to both groups when testing drugs? (11)
This is so the doctor can see the actual difference the drug makes- it allows for the placebo effect.
148
What is the placebo effect?
It is when the patient expects the treatment to work and so feels better, even though the treatment isn't doing anything.
149
What are clinical trials? (12)
They are blind.
150
What does it mean if a clinical trail is blind? (13)
The patient in the study doesn't know whether they're getting the drug or the placebo.
151
What are most clinical trails like? (14)
They're often double-blind.
152
What does it mean if a clinical trail is double-blind? (15)
Neither the patient nor the doctor knows until all the results have been gathered/
153
Why are clinical trails often double-blind? (16)
This is so the doctors monitoring the patients and analysing the results aren't subconsciously influenced by their knowledge.
154
Why are the results of drug testing and drug trails not published yet? (17)
They need to first go through peer review. This helps to prevent false claims.
155
What is peer review?
It is when other scientists check that the work is valid and has been carried out rigorously.
156
What are antibodies produced by?
B-lymphocytes
157
What is B-lymphocytes?
A type of white blood cell.
158
How are monoclonal antibodies produced?
They are produced from lots of clones of a single white blood cell.
159
Give 2 facts about the all the antibodies (Monoclonal antibodies).
1. All the antibodies are identical
| 2. The antibodies will only target one specific protein antigen
160
Give 2 facts about the all the antibodies (Monoclonal antibodies).
1. All the antibodies are identical
| 2. The antibodies will only target one specific protein antigen
161
Why can't you just grab the lymphocyte that made the antibody and grow more?
Lymphocytes don't divide very easily.
162
What are tumour cells able to do?
They don't produce antibodies but divide lots- so they can be grown really easily.
163
How can you create a hybridoma? (1)
By fusing a mouse B-lymphocyte with a tumour cell.
164
What are hybridoma able to do? (2)
They can be cloned to get lots of identical cells.
165
What can hybridoma cells produce? (3)
The same antibodies (monoclonal antibodies).
166
What happens after the same antibodies are produced? (4)
The antibodies can be collected and purified.
167
What can you make monoclonal antibodies to do? (5)
Bind to anything you want.
168
Why are monoclonal antibodies very useful? (6)
They will only bind to (target) this molecule- this means you can use them to target a specific cell or chemical in the body.
169
What is HCG?
It is a hormone found in the urine of women only when they are pregnant.
170
What do pregnancy testing sticks detect?
HCG
171
Give the first step on how pregnancy testing sticks work.
The bit of the stick you wee on has some antibodies to the hormone, with blue beads attached.
172
Give the second step on how pregnancy testing sticks work.
The test strip has some more antibodies to the hormone stuck onto it (so they can't move).
173
What does the stick do when you wee on it (if you are pregnant)?
1. The hormone binds to the antibodies on the blue bead.
2. The urine moves up the stick, carrying the hormone and the beads
3. The beads and hormone bind to the antibodies on the strip
4. So the blue beads get stuck on the strip, turning it blue
174
What does the stick do when you wee on it (if you are not pregnant)?
The urine still moves up the stick, carrying the blue beads. But there's nothing to stick to the blue beads onto the test strip, so it doesn't go blue.
175
What are tumour markers?
It is when cancer cells have antigens on their cell membranes that aren't found on normal body cells.
176
What can you make in a lab with monoclonal antibodies?
You can make monoclonal antibodies that will bind to these tumour makers.
177
What can be attached to monoclonal antibodies?
An anti-cancer drug
178
What can an anti-cancer drug be?
It might be a radioactive substance, a toxic drug or a chemical which stops cancer cells growing and dividing.
179
How are antibodies given to patients?
They are given to the patient through a drip.
180
Why do the antibodies target specific cells (the cancer cells)?
Because they only bind to the tumour makers.
181
What does the drug kill?
The drug kills the cancer cells but doesn't kill any normal body cells near the tumour.
182
Give an example of what monoclonal antibodies could be used for. (1)
Bind to hormones and other chemicals in blood to measure their level
183
Give an example of what monoclonal antibodies could be used for. (2)
Test blood samples in laboratories for certain pathogens.
184
Give an example of what monoclonal antibodies could be used for. (3)
Locate specific molecules on a cell or in a tissue
185
How can you use monoclonal antibodies to locate a specific molecule? (1)
First, monoclonal antibodies are made that will bind to the specific molecules you're looking for.
186
How can you use monoclonal antibodies to locate a specific molecule? (2)
The antibodies are then bound to a fluorescent dye.
187
How can you use monoclonal antibodies to locate a specific molecule? (3)
If the molecules are present in the sample you're analysing, the monoclonal antibodies will attach to them, and they can be detected using the dye.
188
Why is monoclonal antibodies better then other cancer treatments?
Other cancer treatments can affect normal body cells as well as killing cancer cells, whereas monoclonal antibodies target specific cells.
189
Give 2 examples of cancer treatments.
1. Standard chemotherapy
| 2. Radiotherapy
190
Give 3 examples of the side effects of monoclonal antibodies.
1. They can cause fever
2. Vomiting
3. Low blood pressure
191
Why did scientists think monoclonal antibodies won't cause any side effects?
Because monoclonal antibodies targeted a very specific cell or molecule.
192
What would plants suffer from if there aren't enough mineral ions from the soil?
Deficiency symptoms
193
What are nitrates needed for in plants?
They are needed to make proteins and therefore for growth.
194
What will happen to the plant if it has lack of nitrates?
It will have stunted growth
195
What are magnesium ions needed for in plants?
They are needed for making chlorophyll, which is needed for photosynthesis.
196
What do plants suffer from if they don't have enough magnesium ions?
Chlorosis and have yellow leaves.
197
What can plants be infected by?
1. Viral
2. Bacterial
3. Fungal pathogens
198
What can plants be infested and damaged by?
Insects
199
Give an example of an insect that causes damage to the plants.
Aphids
200
Give 6 signs of when a plant has a disease.
1. Stunted growth
2. Abnormal growths, e.g. lumps
3. Spots on the leaves
4. Malformed stems or leaves
5. Patches of decay
6. Discolouration
201
Give a way in which a plant disease could be identified. (1)
Looking up the signs in a gardening manual or on a gardening website.
202
Give a way in which a plant disease could be identified. (2)
Taking the infected plant to a laboratory, where scientists can identify the pathogen.
203
Give a way in which a plant disease could be identified. (3)
Using testing kits that identify pathogen using monoclonal antibodies.
204
Give a physical defence a plant has. (1)
Most plant leaves and stems have a waxy cuticle, which provides a barrier to stop pathogens entering.
205
Give a physical defence a plant has. (2)
Plant cells themselves are surrounded by cell walls made from cellulose. These form a physical barrier against pathogens that make it past the waxy cuticle.
206
Give a physical defence a plant has. (3)
Plants have layers of dead cells around their stems. These act as a barrier to stop pathogens entering.
207
Give a chemical defence a plant has. (1)
Some can produce antibacterial chemicals which kill bacteria.
208
Give a chemical defence a plant has. (2)
Other plants produce poisons which can deter herbivores (organisms that eat plants).
209
Give a mechanical defence a plant has. (1)
Some plants have adapted to have thorns and hairs. These stop animals from touching and eating them.
210
Give a mechanical defence a plant has. (1)
Some plants have adapted to have thorns and hairs. These stop animals from touching and eating them.
211
Give a mechanical defence a plant has. (2)
Other plants have leaves that droop or curl when something touches them. This means that they can prevent themselves from being eaten by knocking insects off themselves and moving away from things.
212
Give a mechanical defence a plant has. (3)
Some plants can cleverly mimic other organisms.
213
Give an example of when plants have layers of dead cells around their stems.
The outer part of the bark on trees.
214
Give 2 examples of plants that are able to produce antibacterial chemicals.
1. Mint plant
| 2. Witch hazel
215
Give 3 examples of plants that produce poison.
1. Tobacco plants
2. Fox gloves
3. Deadly nightshades
216
Give 2 examples of plants who mimic other organisms.
1. Passion flower
| 2. Several species of plants in the "ice plant family"
217
How does a passion flower mimic another organism?
It has bright yellow spots on its leaves which look like butterfly eggs. This stops other butterflies laying their eggs there.
218
How does several species of plants in the "ice plant family" in southern Africa mimic other organisms?
They look like stones and pebbles. This tricks other organisms into not eating them.
219
What is cholera?
It is a bacterial infection that's spread by drinking water contaminated with the diarrhoea of other sufferers.
