B5- Health, Disease, and the Development of Medicines Flashcards
1
Q
What are communicable diseases?
A
Diseases that can spread between people (e.g. coronavirus)
2
Q
What are non-communicable diseases?
A
Diseases that can spread between people (e.g. cancer)
3
Q
What are pathogens?
A
Organisms that cause communicable diseases
4
Q
Examples of pathogens
A
- bacteria
- viruses
- fungi
- protists
5
Q
Define ‘health’
A
A state of complete physical, mental, and social well-being
6
Q
Explain how having one disease can affect the likelihood of a person getting another, different disease
A
As their body may have become weakened by the first disease, so its less able to fight off other diseases
7
Q
Which type of pathogen causes Ebola?
A
A virus
8
Q
Which type of pathogen causes malaria?
A
A protist
9
Q
What would a tree infected with Chalara ash dieback look like?
A
- lost leaves
- have lesions on its bark
10
Q
Cholera is spread by water, how could a person pick up the pathogen that causes cholera?
A
By drinking or bathing in contaminated water
11
Q
How can disease be spread?
A
- through air
- contaminated food
- contaminated water
- exchanging bodily fluids
- carried by an animal vector
12
Q
Why are people infected with tuberculosis advised not to go to school or work, even if they feel well enough to go?
A
- its spread by air so those infected with it should avoid crowded public spaces in case they spread the disease bu coughing near other people
13
Q
Explain how you can reduce the spread of stomach ulcers?
A
They are spread by drinking contaminated water (oral transmission).
- having clean water supplies
- hygienic living conditions
14
Q
Why are viruses said to be dependant on their hosts?
A
They need to infect host cells in order to reproduce and survive
15
Q
Describe the basic structure of a typical virus
A
A typical virus has a strand of genetic material contained within a protein coat
16
Q
Describe how viruses reproduce by the lytic pathway
A
- the virus attaches itself to a specific host cell and injects its genetic material into the cell
- the virus can then replicate its genetic material and reproduce the components of new viruses using proteins and enzymes
- once they’ve been produced, the viral components assemble
- the host cell gets split open releasing new viruses which infect more cells
17
Q
Suggest why the human genome contains viral genetic material?
A
The presence of viral genetic material could have been caused by viruses reproducing by the lysogenic pathway. This involves viruses injecting their genetic material, which is then incorporated into the genome of a host cell
18
Q
One way that the human body tries to fight a viral infection is by destroying cells within the body that are infected by the virus. Suggest how this might help to fight the virus.
A
By destroying cells infected with the virus it can prevent the virus from completing its cycle and producing new viruses. This helps to reduce the number fo viruses in the body that can infect new cells.
19
Q
What pathogen causes chlamydia?
A
Bacterium
20
Q
What cells in the body are killed by HIV?
A
White blood cells
21
Q
How can HIV be spread?
A
The exchange of bodily fluids:
- sharing of needles between drug users
- sexual contact
22
Q
Ways of reducing the spread of HIV:
A
- using condoms when having sex
- drug uses avoiding sharing needles
- using medication (to reduce the risk of passing the virus on to others during sex or infected mother passing the virus to their baby during pregnancy)
23
Q
Ways of reducing the spread of chlamydia:
A
- wearing a condom during sex
- screening individuals so they can be treated
- avoiding sexual contact
24
Q
Explain why someone infected with AIDS is very vulnerable to being infected with other pathogens?
A
AIDS causes an infected person’s immune system to deteriorate and eventually fail. As a result they are less able to fight off infections from other pathogens
25
Physical barriers that protect plants from pests and pathogens:
- waxy cuticle
| - cell walls
26
Two types of chemical responses used by plants:
- some plants produce antiseptics to kill bacteria and fungal pathogens
- some produce chemicals that deter insects from eating their leaves
27
Describe how one chemical produced by a plant is used in medicine
- quinine has been used to treat malaria
| - aspririn used to relive pain an fever
28
Some trees in a forest are infected by an unknown pathogen. The infected trees are randomly distributed throughout the forest. What does this suggest about how the pathogen is spread?
-suggests the pathogen is airborne and spread by the wind
29
How could you test in a field whether the symptoms shown by a plant are caused by nutrient deficiency rather than a pathogen?
- add nutrients to soil
- check for any change in plant’s symptoms
- if plants health improves its likely to have been nutrient deficient rather than infected by a pathogen
30
Why would testing plant tissue for the presence of specific antigens help to determine whether the plant is infected with a disease?
- antigens found on the surface of school plan are unique to each pathogen
- if antigens from a particular pathogen are detected in the plant tissue it show that the plant is infected by that pathogen
31
What chemical that kills bacteria is found in tears?
-lysozyme
32
Which proteins on the surface of plants trigger an immune response?
-antigens
33
What is the role of the skin in protecting the body from pathogens?
-the skin acts as a physical barrier that stops pathogens from entering the body
34
How does the stomach help to defend the body against pathogens?
The stomach produces hydrochloric acid, which kills most pathogens that are swallowed
35
How do cells in the trachea and bronchi help to protect the airway from pathogens?
Some cells in the bronchi and trachea produce mucus which traps pathogens. Other cells have cilia, which move the mucus up to the back of the throat so it can be swallowed
36
Describe the role of antibodies in the immune system’s response o a pathogen
Antibodies bind to the pathogen so it can be found and destroyed by white blood cells
37
How is the immune system able to only attack the invading pathogen and not other cells within the body?
The antibodies that are produced in an immune response are specific to the invading pathogens. This means that they will only bind to the pathogen and not to other cells, so it is only the pathogen that is then destroyed by white blood cells
38
What are memory lymphocytes?
-a type of white blood cell produced in response to the antigens of pathogens. They stay in the body for a long time and produce antibodies against the specific pathogens
39
How does immunisation protect a person from future infections?
- person is injected with a small a pound of dead or inactive pathogens
- antigens on the pathogens trigger the production of both antibodies and memory lymphocytes
- if the person is infected by live pathogens of the same type, then the memory lymphocytes can rapidly produce the antibodies needed to kill it off.
40
Why is the secondary immune response much faster than the first response of the immune system when it first encounters a pathogen?
- when it enters the body for the first time the response is slow because there aren’t many white blood cells that can make the correct antibody
- the secondary immune response is faster because there are already a lot of memory lymphocytes in the body that can produce the antibody
41
Why isn’t it necessary for an entire population to be immunised in order to prevent outbreaks?
If most of the population has been immunised then even those who haven’t are unlikely to get the disease as there are fewer people who are able to pass it to them (HERD IMMUNITY)
42
Why are tumour cells used to produce hybridomas?
Tumour cells can be grown easily, because they divide a lot
43
What type of cell is fused with a tumour cell to produce a hybridoma?
A (mouse) B-lymphocyte — the type of white blood cell that produces antibodies
44
What is attached to the test trip of a pregnancy test before it is used?
Monoclonal antibodies
45
How are hybridomas used to reduce monoclonal antibodies?
Hybridomas are cloned to get lots of identical cells. These divide quickly to produce large amounts of the same antibodies, which are collected and purified.
46
Pregnancy testing kits detect whether the hormone HCG is present in a urine sample. Why does the pregnancy test strip turn blue when HCG is present?
The part of the stick that you wee on has antibodies with blue beads attached to them. If HCG is present, it binds to these antibodies. The urine travels up the stick carrying the hormone ad beads to the test strip, where the hormones binds to the antibodies there. The test strip therefore turns blue because the blue bead have become stuck it.
47
Why doesn’t the test strip turn blue when HCG is absent?
The antibodies and the attached blue beads still move up the stick, but there is no hormone bound to them, so they don’t stick to the antibodies on the test strip. The blue beads therefore get carried beyond the test strip so the test strip doesn’t turn blue.
48
What do antibodies bind to on the surface of cancer cells?
Tumour markers
49
Antibodies are used to locate blood clots, what do these antibodies bind to?
Bind to the proteins in the blood (that join together when blood clots form)
50
Explain why radioactive elements are attached to antibodies when they locate blood clots.
The radioactive element produces radiation, so we can find out where the antibodies end up in the body by taking a picture with a camera that detects radiation. Lots of antibodies bind to a blood clot and this will show as a bright spot on the picture, showing us where the blood clot is located. (Radiotherapy)
51
Which pathogen do antibiotics treat?
-bacteria (they’re ineffective on the others)
52
What does it mean when patients are given a placebo?
They have been given a substance that looks like the real drug but does nothing
53
Why are drugs tested on healthy volunteers during clinical testing?
To make sure the drug doesn’t have any harmful side effects when the body is working normally
54
What can scientists learn from giving the drug to live normal during preclinical testing?
whether the drug works, how toxic it is and the best dosage to use
55
How could a double blind trial be used to test how well this drug works on a group of patients?
-patients are randomly split into groups
-one group is given the drug and the other is given a placebo
In a double blind trial neither the doctor nor the patients know who has been given the drug and who has been given the placebo until after the results have been collected. Therefore, no one is influenced by their knowledge. The results from both groups are compared to see how well the new drug works.
56
How would you sterilise an inoculating loop?
By passing it through a hot flame
57
Why do you need to close the Petri dish immediately after you’ve transferred the bacteria into the dish when culturing microorganisms?
To prevent microorganisms from the air getting into the Petri dish
58
Why are Petri dishes and growth media are placed in an autoclave before hey are used to culture bacteria?
They are put in an autoclave so they can be sterilised. An autoclave uses steam at a high pressure and temperature to kill any microorganisms present. This prevents unwanted microorganisms from affecting the results.
59
Zaha is performing an experiment to test the effect of a plant on bacteria. The plant is known to produce a powerful antiseptic. Zaha places paper discs soaked in the plot extract on an agar plate that has an even covering of bacteria. What will the plate look like after being left for 48 hours at 25°C? Explain why.
There will be a clear ring around each paper disk where there will be no bacteria growing, while the rest of the agar plate will be covered in bacteria. This is because the plant extract will have diffuse out the paper disks and into the agar around them, causing the bacteria in that area to die.
60
Why do you leave agar plates at 25°C instead of room temperature which is 18°C when culturing microorganisms?
Bacteria will grow faster will at 25°C than they will at 18°. Leaving the plate at 25°C could therefore make it easier to tell where on the plate bacteria have been able to grow.
61
Name the clear area that forms around the disc on the agar plate when bacteria die
Inhibition zone
62
Name one organ affected by drinking too much alcohol
Liver (can cause liver disease)
63
Two factors for obesity:
- not getting enough exercise
| - having a diet high in fat and sugar
64
What causes malnutrition? Why is it a problem in developing countries?
- having a diet with too many or too few nutrients
| - people in developing countries are jot able to access enough food
65
Why is there more pressure on the resources of local hospitals in areas with higher rates of obesity?
Obesity is a risk factor for other non-communicable diseases (e.g. cardiovascular disease). An area with a higher rate of obesity is therefore likely to have higher occurrence of these diseases, so the hospitals will be under more pressure to treat all the people who suffer from them.
66
Why does someone smoking increase the chance of them having a heart attack?
Nicotine in cigarette smoke increases heart rate, which increases blood pressure. High blood pressure damages artery walls, which contributes to the build up of fatty deposits in the arteries. These deposits restrict blood flow and increase Howe risk of a heart attack. Smoking also increases the risk of blood clots forming in the arteries, which can restrict or block blood flow, leading to a heart attack.
67
Doctors can never be sure that smoking is the only reasons why a patient has cardiovascular disease, even when the patient is a heavy smoker, why?
Cardiovascular is often caused by many different risk factors interacting with each other, rather than one factor alone
68
What equation is used to calculate BMI?
BMI = mass (kg) ÷ (height (m))²
69
Why is BMI not always a reliable measure of obesity?
People with lot of muscle have high mass, so their BMI will be high and they might be classified as overweight or obese. However, these people are likely to do a lot of exercise and actually be healthy. BMI is therefore not reliable in these cases
70
What are antihypertensives?
Drugs that reduce blood pressure
71
Why does a patient need to take drugs after being given a donor heart?
to stop the body’s immune system from rejecting the donor heart
72
What is a stent?
A tube inserted into an artery
73
How do stents reduce the risk of a heart attack?
They keep the arteries open so that the blood can pass through to the heart muscles, lowering the risk of a heart attack.
74
How do statins reduce the risk of heart attacks and strokes?
They reduce cholesterol in the bloodstream, slowing down the rate at which fatty deposits form
75
Why could a doctor recommend lifestyle changes first to a patient with cardiovascular disease, rather than recommend heart surgery straight away?
Lifestyle changes can reduce the risk of a heart attack or stroke and don’t have any major downsides. If a patient has heart surgery there is a risk of bleeding, clots and infection, so the patient should only have heart surgery when it is really necessary.
