B6.3 Flashcards
(164 cards)
1
Q
What is health?
A
The state of physical and mental wellbeing.
2
Q
What is a disease?
A
A disorder that affects the body, organs, or cells.
3
Q
What are the two types of disease?
A
Communicable and non-communicable.
4
Q
What are communicable diseases?
A
Diseases caused by pathogens that can spread between people - contagious
5
Q
Examples of communicable disease?
A
chickenpox, malaria, HIV
6
Q
What are non-communicable diseases?
A
Diseases that do not spread between people - non contagious
7
Q
Examples of non-communicable diseases?
A
diabetes, heart conditions, neurological diseases, cancer
8
Q
What lifestyle factors cause non-communicable diseases?
A
Diet, stress, lack of exercise, alcohol
9
Q
How does HIV affect susceptibility to disease?
A
Weakens the immune system so the body is more vulnerable to infections like TB.
10
Q
What is tuberculosis (TB)?
A
A bacterial infection that mainly affects the lungs; more likely in HIV patients.
11
Q
How is HPV linked to cancer?
A
The virus can live in cells and trigger cancers such as cervical cancer.
12
Q
What do viruses do in the body?
A
Infect and live inside host cells, replicate DNA, burst out to infect other nearby cells.
13
Q
Can antibiotics treat viral infections?
A
No
14
Q
How does HIV spread?
A
Bodily fluids (e.g. sexual activity, sharing needles, from mother to baby:feeding)
15
Q
Symptoms of HIV?
A
Initial flu-like symptoms
16
Q
What does HIV develop into?
A
AIDS – immune system is damaged and fails
17
Q
Prevention for HIV?
A
Use condoms, avoid sharing needles, bottle-feed babies of HIV+ mothers
18
Q
Treatment for HIV?
A
No cure, but antiviral drugs slow progression to AIDS
19
Q
What is a viral infection in humans?
A
HIV
20
Q
What is a viral infection in plants?
A
Tobacco Mosaic Virus (TMV)
21
Q
What does TMV do to plants?
A
Infects chloroplasts, reduces photosynthesis by creating mosaic white spots
22
Q
How does TMV spread?
A
Contact between plants
23
Q
How is TMV prevented?
A
Good field hygiene, pest control, grow TMV-resistant strains
24
Q
What is a bacterial disease in humans?
A
Salmonella
25
What is Salmonella?
A type of food poisoning caused by bacteria in animal gut
26
Symptoms of Salmonella?
Fever, stomach cramps, vomiting, diarrhoea
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Spread of Salmonella?
Raw meat, eggs, unhygienic food practices
28
Prevention of Salmonella?
Wash hands/surfaces, cook food thoroughly, avoid raw and cooked food contact
29
What is a bacterial disease in plants?
Crown gall disease
30
What does crown gall disease do?
Transfers bacterial DNA into plant’s DNA
31
Symptoms of crown gall?
Tumours develop in roots/stems, plant becomes stunted
32
What is a fungal disease in humans?
Athlete’s foot
33
Symptoms of Athlete’s foot?
Red or white flaky rash between toes
34
How does it spread?
Touching infected skin/surfaces, often in swimming pool changing rooms
35
Treatment for Athlete’s foot?
Antifungal medication
36
What is a fungal disease in plants?
Barley Powdery Mildew
37
What does barley powdery mildew do?
Affects grass plants like barley, plant will be unable to make chlorophyll so cannot photosynthesise
38
Symptoms of barley powdery mildew?
Circular fluffy white growth, spores spread by wind - hyphae produced on upper & lower leaf surfaces
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Spread of barley mildew?
Common in cool, damp environments
40
Treatment barley mildew?
Fungicides, removing infected leaves
41
What is a protist disease in humans?
Malaria
42
What is malaria caused by?
Protists that infect red blood cells - pathogens replicate & RBCells burst to spread pathogen further
43
Symptoms of malaria?
Shivering and fever
44
How does malaria spread?
Female Anopheles mosquito (vector); saliva enters bloodstream
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How is malaria prevented?
Insecticide nets, remove stagnant water, antimalarial drugs
46
How can communicable diseases be identified or reduced?
Visual identification
Screening for antibodies (e.g. HIV)
DNA identification (e.g. Agrobacterium)
47
What are physical plant defences?
Bark: barrier of dead cells
Cell wall: made of cellulose
Leaf cuticle: waxy layer to block pathogens
48
What are chemical plant defences?
Antimicrobial substances: e.g. mint, witch hazel – act as antiseptics
Poisons: e.g. stinging nettles release poison to avoid being eaten
49
What does ELISA Test stand for?
Enzyme-Linked Immunosorbent Assay
50
What is ELISA used for in plants?
To detect whether a plant contains a pathogen antigen - therefore if it’s infected
51
What are the 7 steps of ELISA?
1. Liquidise plant sample
2. Add sample to plastic tube/microtiter plate
3. Leave for 5 mins so proteins in plant bind to plastic
4. Wash the wells with buffered salt solution to remove unbound excess proteins
5. Add blocking agent to block uncoated plastic, then wash again with salt solution
6. Add antibody-enzyme complex specific to pathogen antigen, then wash again with salt solution
7. Add colourless substrate – enzyme changes it to a coloured product if antigen is present
52
What PCR stand for
Polymerase Chain Reaction
53
What is PCR used for?
To copy small DNA sections billions of times.
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What is added to the PCR tube?
2 primers, nucleotides, and DNA polymerase
55
What does DNA polymerase do?
Reads DNA, makes a copy by attaching nucleotides at a primer
56
What does 2 primers do?
they are short pieces of DNA, are needed to match each end of the DNA segment that is meant to be copied
57
What are the temperature stages of PCR?
95°C: DNA heated to 95 to unzip DNA and denature
55°C: DNA cooled to 55 to allow primers to anneal
72°C: DNA heated to optimum temp for DNA polymerase to work
58
What is observation used for in plant disease detection?
Look, feel, smell of plants – check for fungus, stunted growth, etc.
59
What is the purpose of non-specific defences?
Prevent pathogens from entering the body.
60
What are the 5 main non-specific defences?
Skin
Nose
Trachea and bronchi
Stomach
Phagocytic white blood cells
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Skin - non specific defence - what does it do?
- acts as physical barrier
- Produces antimicrobial secretions to kill pathogens
- Contains skin flora (good microorganisms that outcompete pathogens for space & nutrients’)
63
Nose - non specific defence - what does it do?
Hairs and mucus trap particles - prevents them from entering lungs
64
Trachea and bronchi - non specific defence - what does it do?
Secrete mucus - trap pathogens
Cilia (hair like structures on cells) waft & move mucus upwards to be swallowed
65
Stomach - non specific defence - what does it do?
Produces hydrochloric acid to kill pathogens
66
Phagocytic white blood cells - non specific defence - what does it do?
Do phagocytosis: engulf and digest pathogens (non-specific - can do for any pathogen)
67
What are the 2 specific functions of white blood cells?
Produce antibodies (lymphocytes) Produce antitoxins
68
What does the white blood cell lymphocytes do (antibodies)
Each pathogen has antigens on its surface - complementary antibodies can bind to it
Antibodies bind to specific antigens
Which Causes pathogens to clump together – easier for white blood cells to find
Upon reinfection, faster antibody production = immunity
69
What do antitoxins from white blood cells do?
Allows WBCells to neutralise toxins released by pathogens by binding to them
70
What are platelets?
Blood components that help form clots.
71
How do platelets form clots?
Have surface proteins to clump together
Trigger a clotting cascade (chain of chemical reactions)
72
What are monoclonal antibodies?
Identical antibodies from the same lymphocyte that bind to one specific antigen.
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What are the 6 steps to make monoclonal antibodies?
1. Inject antigen into a mouse
2. Mouse produces lymphocytes against specific antigen
3. Remove spleen cells (where lymphocytes are made)
4. Spleen cells combine with cancerous myeloma cells → form hybridoma
5. Hybridoma clones itself to produce lots of same antibody
6. Antibodies are collected and purified
74
What hormone do pregnancy tests detect?
hCG – human chorionic gonadotrophin
75
What are the 2 sections of a pregnancy test?
1st section - Mobile antibodies: Complementary to hCG, attached to blue beads
2nd section - Stationary antibodies: Fixed in place, also bind hCG
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What happens when hCG is present? - pregnancy tests
hCG binds to mobile antibodies → forms hCG-antibody complex
Complex is carried to stationary antibodies
As they are each bound to a blue head:Blue line appears → positive result
77
How do monoclonal antibodies help detect cancer?
Bind to antigens on cancer cells, cause them to clump
Can carry fluorescent dye to highlight tumour location
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How do monoclonal antibodies treat cancer?
Drugs are attached to deliver toxic substances directly to tumour
Encourage WBCs to attack cancer
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Advantages of Monoclonal Antibodies
Bind to specific cells only – healthy cells unaffected
Can be engineered for many conditions
Mouse-human hybrid cells reduce immune response risk
80
Disadvantages of Monoclonal Antibodies
Hard to attach them to drugs
Expensive to develop
May trigger immune response in humans (from mouse lymphocytes)
81
What is a vaccine?
dead/inactivated form of pathogen that triggers an immune response.
82
How do vaccines protect against disease?
WBCs make complementary antibodies
On reinfection: faster antibody production, no symptoms
Creates immunity
83
What is herd immunity?
Immunising a large % of the population so fewer people catch and spread the disease.
84
What have vaccinations achieved so far?
Eradicated many diseases (e.g. smallpox)
Reduced occurrence of others (e.g. rubella)
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How do vaccinations help prevent epidemics?
Through herd immunity, reducing lots of cases in an area
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What is a disadvantage of vaccination?
Not always effective in providing immunity
87
What rare side effects can vaccines cause?
Bad reactions like fevers (very rare)
88
What are antibiotics used for?
Kill bacterial pathogens inside the body
Do not damage body cells
89
Why can’t antibiotics be used to treat viruses?
Viruses live inside body cells, so targeting them would damage tissue
90
How can antibiotics be taken?
Pill
Syrup
Directly into bloodstream
91
Why is it important to use the correct antibiotic?
Different antibiotics target different bacteria types
92
What is the impact of antibiotics on health?
Reduced deaths from bacterial diseases (e.g. Penicillin)
93
What causes antibiotic resistance?
Mutations during reproduction make bacteria resistant
94
What happens when bacteria are exposed to antibiotics?
Only non-resistant ones die
Resistant bacteria survive and reproduce
95
What is the problem with antibiotic resistance?
Previously effective antibiotics no longer work
Makes bacterial infections hard to treat
96
How can resistance be prevented?
Avoid overuse of antibiotics
Always complete the full course of treatment
97
What are antivirals used for?
Treat viral diseases
Stop virus replication
98
Why is killing viruses difficult?
Viruses hijack cells to replicate
Killing the virus may damage human cells
99
How do antivirals work?
Prevent the virus from copying its DNA
Stop replication
100
What are antiseptics?
Chemicals that kill foreign microorganisms
101
Where are antiseptics commonly used?
To sterilise wounds
Prevent infection and disease spread
102
Why are antiseptics and antibiotics tested on agar plates first?
To check their effectiveness
103
Why are aseptic techniques used?
Prevent contamination of pure cultures
Ensure accurate results
104
What is done to the workspace before beginning?
Cleaned and sprayed with disinfectants
105
How are petri dishes and agar gel sterilised?
In an autoclave
106
What is done after agar is poured?
Allowed to set in sterile petri dishes
107
Why work around a blue Bunsen flame?
Creates an updraft to stop airborne bacteria from contaminating
108
How is the bacterial suspension prepared?
Swirled (not shaken)
109
How is the inoculating loop sterilised?
Heated in a blue Bunsen flame or cleaned with pure alcohol
110
Why flame the neck of the bacterial bottle?
To kill unwanted bacteria
111
How are separate bacterial colonies made?
Dip loop in solution and streak on agar plate
112
How should the petri dish be stored?
Lid taped on
Labelled on the bottom
Stored upside down
113
Why shouldn’t the petri dish be fully sealed?
So oxygen can enter and bacteria can respire aerobically
114
What temp should the plate be incubated at? Why?
Max 25°C
Reduces harmful bacterial growth (pathogens grow at 37°C)
115
What happens after the experiment?
Dispose of contaminated materials
Disinfect surfaces
116
What is the zone of inhibition?
Area around antibiotic where bacteria stopped growing
117
How is the zone of inhibition measured?
Measure diameter
Divide by 2 to find radius
Use area of circle formula: πr²
118
What does a larger zone of inhibition mean?
More effective antibiotic or antiseptic
119
Where do most new drugs come from?
Plants used in traditional healing
120
Example of a plant-based medicine?
Willow bark used for fever → now used to make aspirin
121
Why is rainforest destruction a concern for medicine?
May destroy plants/organisms that could help modern medicine
122
What are preclinical drug trials?
Tests using computer models or human cells to see drug effects before animal/human testing.
123
Why are preclinical trials important?
To check safety on living cells before testing on animals.
124
Is animal testing for medicine legal in the UK?
Yes, but not for cosmetic products.
125
Why are drugs tested on animals?
To observe side effects and adjust dosage.
126
What are human clinical trials?
Tests on healthy volunteers, then target patients in increasing doses.
127
What is a placebo?
An inactive version of the drug used to compare against the real drug in trials.
128
What is a blind trial?
Patients don’t know if they receive the real drug or placebo—helps test drug’s true effect.
129
What was Thalidomide and why was it dangerous?
A sleeping pill given to pregnant women, caused birth defects due to lack of proper testing.
130
What are non-communicable diseases (NCDs)?
Diseases not spread between people, e.g., CVD, cancer, type 2 diabetes, liver disease.
131
How does obesity affect health?
Increases blood pressure and insulin resistance, raising type 2 diabetes risk.
132
What liver damage does alcohol cause?
Fatty liver - lipids to build up
alcoholic hepatitis - liver becomes inflamed
liver cirrhosis - scarred liver - no longer function
133
What brain effects can alcohol cause?
Brain shrinkage, memory loss, psychiatric problems.
134
How does smoking increase CVD risk?
Damages artery lining, increases fatty build-up, risk of heart attacks/strokes.
135
How do chemicals in cigarettes affect the heart?
Increase blood clots and heart rate (nicotine), reduce oxygen (carbon monoxide).
136
What can carcinogens in cigarettes cause?
Lung cancer.
137
What is COPD and how is it caused?
Chronic Obstructive Pulmonary Disease caused by inflammation and mucus in lungs - hard to breathe
138
What causes heart attacks?
Cholesterol and fatty deposits block coronary arteries, stopping oxygen to the heart.
139
What are symptoms of heart attacks?
Chest pain (angina), heart tissue dies if untreated.
140
Risk factors for CVDs?
Smoking, high blood pressure, high salt/saturated fat in diet.
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Lifestyle choices to treat CVD?
Exercise, no smoking, lose weight, less saturated fat.
142
What are statins?
Drugs that reduce cholesterol production in the liver.
143
Who are statins given to?
Those with heart disease or high risk.
144
Side effects of statins?
Must be taken long-term; not suitable for people with liver disease.
145
What are stents?
Wire mesh tubes inserted to keep arteries open; made of metal alloys (avoid immune rejection).
146
What is coronary artery bypass surgery?
Graft from another body part creates new path for blood around blockage.
147
When is a heart transplant needed?
For heart failure—when it can’t pump blood effectively.
148
What is the risk of heart transplants?
Long wait, rejection risk, need for immunosuppressants (↑ infection risk).
149
What are artificial hearts used for?
Temporary support while waiting for transplant.
150
What is cancer?
Uncontrolled cell growth and division.
151
What is a benign tumour?
Grows slowly, doesn’t spread, can be removed.
152
What is a malignant tumour?
Grows quickly, cancerous, spreads via bloodstream (metastasis).
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Cancer risk factors?
Carcinogens, age, genetic factors (e.g. BRCA1), HPV, smoking.
154
Lifestyle factors that increase cancer risk?
Alcohol (liver), UV radiation (skin), asbestos exposure.
155
What are stem cells used for in medicine?
Replace damaged cells (e.g. type 1 diabetes, paralysis), grow organs.
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What are bone marrow transplants used for?
Treat blood cancers like leukaemia.
157
Advantages of stem cells?
Can grow whole organs, no rejection if from body.
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Risks of stem cells?
Ethical issues, mutations, hard to find donors, uncertain success.
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What is genetic engineering used for in medicine?
Make insulin, treat inherited conditions, and test for diseases.
160
How is insulin produced using genetic engineering?
Gene cut with restriction enzymes, inserted into plasmid, taken up by bacteria via binary fission.
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How can inherited conditions be treated?
Replace faulty gene with working one via genetic engineering.
162
What is Huntington’s disease?
Genetic disease tested before symptoms show, helps with family planning.
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What is the Human Genome Project?
Research to identify all human genes.
164
Benefits of the Human Genome Project?
Understand genetic causes of disease, predict likelihood, and improve drug effectiveness.
