Topic 3: Infection and Response F Flashcards
1
Q
What is a pathogen?
A
A microorganism that enters the body and causes disease
2
Q
What is a communicable disease?
A
An infectious disease caused by a pathogen
3
Q
What are bacteria?
A
Very small cells which can rapidly reproduce in your body
4
Q
How big are bacteria cells?
A
1/100th the size of your body cells
5
Q
How do bacteria make you feel ill?
A
They produce toxins which damage your body cells and tissues
6
Q
How do viruses make you feel ill?
A
They live inside your cells and replicate themselves to produce many copies. The cell usually then bursts, releasing the viruses and making you feel ill from the cell damage
7
Q
How big are viruses?
A
1/100th the size of a bacterium
8
Q
What are protists?
A
Eukaryotes, mostly single celled
9
Q
How can pathogens be spread?
A
water, air or direct contact
10
Q
What pathogen causes measles?
A
virus
11
Q
What pathogen causes HIV?
A
virus
12
Q
What pathogen causes TMV?
A
virus
13
Q
What pathogen causes rose black spot?
A
fungi
14
Q
What pathogen causes malaria?
A
protist
15
Q
What pathogen causes salmonella?
A
bacteria
16
Q
What pathogen causes gonorrhoea?
A
bacteria
17
Q
How measles spread?
A
droplets from an infected person
18
Q
What are the symptoms of measles?
A
Red skin rash and fever
19
Q
What can complications of measles lead to?
A
pneumonia or brain inflammation
20
Q
How is HIV spread?
A
sexual contact or exchange of bodily fluids
21
Q
What are the symptoms of HIV?
A
flu-like symptoms
22
Q
How is measles treated/prevented?
A
vaccinations as a child
23
Q
How can HIV be treated/prevented?
A
antiretroviral drugs to stop the virus from replicating
24
Q
What can complications of HIV lead to?
A
AIDS- if the immune system is badly damaged it can’t cope with other infections
25
What are the symptoms of TMV?
mosaic pattern on the leaves of the plant and discolouration (reducing photosynthesis and therefore growth)
26
What are the symptoms of rose black spot?
purple/black spots on leaves which then turn yellow and drop off (reducing photosynthesis and therefore growth)
27
How can rose black spot be treated?
fungicides, removing affected leaves then destroying them
28
What is a vector?
An organism which carries the disease and can pass it on but doesn't get the disease itself
29
What is the life cycle of malarial protists?
mosquitoes pick up malaria when feeding on an infected animal and act as vectors by infecting another animal by feeding on it
30
What are the symptoms of malaria?
fever, muscle pains, headache
31
How can the spread of malaria be reduced?
Stopping mosquito from breeding (suffocating larvae, getting rid of stagnant water pools) or mosquito nets/insecticides
32
What are the symptoms of salmonella?
fever, stomach cramps, vomiting, diarrhoea
33
What causes salmonella?
eating contaminated food (unhygienic conditions or an animal which already has the disease)
34
How is the spread of salmonella controlled?
vaccinations given to poultry and preparing food in hygienic conditions
35
How is gonorrhoea passed on?
sexual contact (it is an STD)
36
What are the symptoms of gonorrhoea?
pain urinating, vaginal/penile discharge
37
How can gonorrhoea be treated/prevented?
antibiotics and barrier methods(like condoms)
38
How can the spread of disease be reduced/prevented?
Being hygienic, destroying vectors, isolating infected individuals and vaccination
39
How does your skin defend against disease?
acts as a barrier and secreted antimicrobial substances which kill pathogens
40
How do hairs and mucus defend against disease?
trap particles which can contain pathogens
41
How do trachea and bronchi defend against disease?
they secrete mucus to trap pathogens
42
What are cilia and how do they defend against disease?
hair-like structures which waft mucus to the back of the throat to be swallowed (and go to the stomach)
43
How does the stomach defend against disease?
produces hydrochloric acid to kill pathogens
44
How do white blood cells defend against disease?
consuming pathogens
producing antibodies
producing antitoxins
45
Explain how white blood cells consume pathogens?
they can engulf and digest foreign cells. this is called phagocytosis
46
Explain how white blood cells produce antibodies?
Each invading pathogen has antigens on its surface. Some types of white blood cells produce proteins called antibodies which can lock onto the invading cells so they can be found and destroyed by other white blood cells- antibodies are specific to each type of antigen
47
What happens when the right antibody is produced?
They are produced rapidly and carried around the body. If the person is infected with the same pathogen again, then the white blood cells will rapidly produce the antibodies to kill it
48
Explain how white blood cells produce antitoxins?
They counteract toxins produced by the invading bacteria
49
How do vaccinations work?
small amounts of dead/inactive pathogen which carry antigens are injected. This causes your body to produce antibodies to attack them, even though the pathogen is harmless, so that if live pathogens enter your body the white blood cells can rapidly produce the antibodies needed to kill of the pathogen
50
What are the pros of vaccination?
They have helped control a lot of communicable diseases
Epidemics can be prevented if a large percentage of the population are vaccinated
51
What are the cons of vaccination?
They don't always work
Vaccines can have bad side effects
52
What do painkillers do?
Reduce the symptoms of a disease without killing the pathogen or tackling the cause
53
What do antibiotics do?
kill/ prevent the growth of bacteria without killing your own body cells
54
Why is it hard to find drugs to destroy viruses?
Viruses reproduce in your body's cells so it is hard to destroy them without using your body's cells
55
What is aspirin and where is it found?
used as a painkiller and to lower fever- found in willow
56
What is digitalis and where is it found?
used to treat heart conditions- developed from a chemical found in foxgloves
57
How was penicillin found?
Extracted from microorganisms
58
What are the 3 main stages in drug testing?
preclinical on human cells/tissues
preclinical on live animals
clinical on human volunteers
59
Describe the first step in preclinical testing?
drugs are tested on human cells and tissues, BUT this can't be used to test drugs that affect the whole body system
60
Describe the second step in preclinical testing?
drugs are tested on live animals for efficacy, whether it is harmful and the best dosage
61
What is efficacy?
Whether the drug works and produces the effect you're looking for
62
Describe clinical testing?
1) healthy male volunteers to test for any side effects. The dosage is small to begin with and then gradually increased
2) people suffering from the illness to find the optimum dose (most effective, least side effects)
63
What is a placebo?
a substance like the drug being tested but doesn't do anything so the doctor can see the actual difference the drug makes without having to account for the placebo effect
64
What is a double blind trial?
The patient and the doctor don't know who is getting a placebo, so the doctors aren't subconsciously influenced by their knowledge
65
What are antibodies produced by?
B-Lymphocytes
66
How is a hybridoma cell made?
b-lymphocytes from a mouse (which produce antibodies but can't divide very easily) are fused with tumour cells (which don't produce antibodies but divide lots)
67
How do you get monoclonal antibodies from a hybridoma cell?
hydridoma cells can be cloned to get lots of identical cells. These then produce lots of antibodies which can be collected and purified
68
What do pregnancy tests detect?
HCG, found in the urine of pregnant women
69
How does a positive pregnancy test work?
You wee on the stick which has antibodies for HCG attached to blue dye. The HCG binds to the antibodies and the urine moves up the strip carrying the hormone and blue dye. The beads and hormone bind to the fixed antibodies on the test strip and turn it blue
70
How does a negative pregnancy test work?
The urine moves up the stick carrying the blue dye but there is nothing for the blue dye to attach to on the test strip, so it doesn't go blue
71
What are monoclonal antibodies used for?
they can bind to hormones and other chemicals in the blood to measure their levels
they can test blood samples for specific pathogens
they can locate specific molecules by binding the antibodies to a fluorescent dye, which will then bind to any of the molecules present (can be detected by the dye)
72
What are the advantages of monoclonal antibodies?
cancer treatments- they can target specific cells , so there is lower risk of side effects
73
What are the disadvantages of monoclonal antibodies?
Cause more side effects than was originally expected: fever, vomiting, blood pressure so they aren't as widely used as it was thought they might be
74
When do plants suffer deficiency symptoms?
If there aren't enough mineral ions in the soil
75
What are nitrates needed for and what are the symptoms of a deficiency?
Nitrates are needed to make proteins and therefore for growth. A deficiency causes stunted growth
76
What are magnesium ions needed for and what are the symptoms of a deficiency?
Magnesium ions are needed for making chlorophyll and therefore for photosynthesis. A deficiency give plants yellow leaves or chlorosis
77
What are the common signs of disease in plants?
stunted/abnormal growth
spots on the leaves/discolouration
malformed stems/leaves
patches of decay
78
How can plant diseases be identified?
Looking up the signs in a gardening manual/website
Taking the plant to a lab where they can identify the pathogen
Using a testing kit to identify the pathogen using monoclonal antibodies
79
Name 3 physical defences of a plant
Most leaves and stems have a waxy cuticle which provides a barrier to stop pathogens entering
Plant cells are surrounded by cellulose cell walls which form another physical barrier against pathogens
Plants have layers of dead cells around their stems (like bark) which act as a barrier to stop pathogens from entering
80
Name 2 chemical defences of a plant
Some can produce antibacterial chemicals which kill bacteria
Some plants produce poisons which can deter herbivores
81
Name 3 mechanical defences of a plant
Some plants have thorns and hairs to stop animals from touching or eating them
Some plants have leaves that droop or curl, so they can move away from danger or knock insects off themselves
82
