B6.3 Flashcards
1
Q
what is a disease?
A
a condition which is caused by any pert of the body not functioning properly
2
Q
what are the two main categories of disease?
A
communicable and non communicable
3
Q
what are communicable diseases?
A
diseases which can be spread between organisms
4
Q
what are the majority of communicable diseases spread by?
A
microorganisms which can cause disease known as pathogens
5
Q
what is a pathogen?
A
a disease causing microorganism
6
Q
give an example of a fungal infection in plants
A
powdery mildew
7
Q
give an example of a fungal infection in animals
A
athletes foot
8
Q
give an example of bacterial infection in plants
A
crown gall disease
9
Q
give an example of a bacterial infection in animals
A
tuberculosis
10
Q
give an example of a viral infection in plants
A
tobacco mosaic disease
11
Q
give an example of a viral infection in animals
A
influenza
12
Q
give an example of a protozoa infection in plants
A
coffee phloem necrosis
13
Q
give an example of a protozoa infection in animals
A
malaria
14
Q
what are non-communicable diseases?
A
diseases which cant be spread between organisms
15
Q
give 4 causes of non-communicable diseases
A
poor diet, obesity, inheriting genetic disorder, body processes not operating correclty
16
Q
what can poor diet cause?
A
a diet without enough fresh fruit/ vegetables can cause vitamin and mineral deficiencies
17
Q
what 4 things can obesity lead to?
A
arthritis, type 2 diabetes, heart disease, stroke
18
Q
what is cystic fibrosis?
A
a genetic disorder passed on through genetic material
19
Q
what could cells rapidly dividing uncontrollably due to body processes not working properly cause?
A
cancer
20
Q
what 2 conditions contain both communicable and none communicable disease?
A
human papilloma virus (HPV) and human immunodeficiency virus (HIV)
21
Q
what does HPV cause?
A
cell changes that leads to most forms of cervical cancer
22
Q
what treatment is there for HPV?
A
routine vaccination in girls in the UK has significantly decreased the number of cases. people with HPV also usually recover without long term problems
23
Q
what does HIV cause?
A
AIDS (acquired immune deficiency syndrome)
24
Q
what does HIV do to the person with it?
A
it weakens their immune system making it easier for other microorganisms to cause disease
25
what happens to most people with HIV?
they get infected with tuberculosis causing bacteria and die from it
26
what is high blood pressure caused by?
excess salt intake
27
what is pneumonia caused by
bacteria
28
what is measles caused b?
morbillivirus
29
what is haemophilia caused by?
inherited gene
30
what are the 4 main ways pathogens can spread between animals?
cuts in the skin, digestive system, respiratory system, reproductive system
31
what o organisms living closely increase the risk of?
increases the risk of disease being passed on
32
what three ways can pathogens spread between plants?
vectors, direct contact, wind
33
what are vectors in terms of spreading disease?
insects
34
how could disease in plants be spread through direct contact?
direct contact of sap from a healthy to unhealthy plant which can be released from agricultural damage or through animals feeding on the plants
35
how could disease in plants be spread through the wind?
fungal spores can be blown between plants and infected seeds can be blown across long distances
36
what is incubation period?
time between contracting a disease and the disease symptoms showing
37
what happens in the incubation period?
pathogens reproduce rapidly causing cell damage and some produce toxic waste products
38
what do toxins produced by microorganisms cause?
symptoms such as fever, rashes and sores
39
how do viruses reproduce?
they take over a hosts cells to make more viruses and cant replicate on their own
40
what are the five steps to virus reproduction?
1) virus attacks cells
2) virus inserts genes
3) "tells" nucleus to copy its genes
4) new viruses are made
5) cell bursts releasing new viruses and destroying the cells
41
what is the incidence of a disease?
the number of new cases of a disease per unit of population per time
42
what do the resulats from studying the incidence of a disease provide?
provide scientists with evidence of the effectiveness of the disease treatment and prevention techniques
43
what is the shape of a graph if you were to plot the growth of a bacterial colony
exponential
44
what 8 ways can you prevent disease from spreading?
1) covering your mouth/nose when coughing/sneezing
2) not touching infected people/objects
3) using protection in sex
4) not sharing needles
5) washing hands
6) cooking food properly
7) drinking clean water
8) protecting yourself from animal bites
45
how can you cover your mouth/nose when coughing/sneezing to prevent spreading disease?
using a tissue and discarding of it
46
how can not touching infected people/objects prevent the spread of disease?
some diseases can be spread through direct and indirect contact eg. chicken pox
47
how can using protection in sex prevent the spread of disease?
exchange of bodily fluids can spread disease and protection such as condoms prevent STIs
48
how can not sharing needles prevent spreading disease?
HIV and hepatitis can be spread through blood on needles so disposing of them immediately prevents this risk
49
how can washing hands prevent spreading disease spreading?
it kills pathogens on your hands
50
how does cooking food properly prevent disease spreading?
cooking food can prevent food poisoning as it kills harmful bacteria
51
how does drinking clean water prevent disease spreading ?
untreated water can contain dangerous microorganisms
52
how does protecting yourself from animal bites prevent diseases from spreading?
it prevents pathogens from the animal being spread into your bloodstream
53
how are diseases identified? 3 ways
1) identifying change to an organisms appearance
2) identifying pathogens in DNA
3) antigens
54
what are antigens?
proteins on the surface of a microorganism
55
what 7 ways can farmers prevent disease in plants and animals spreading?
1) burning diseased plants
2) treating animals with vaccines
3) slaughtering herds with incurable diseases
4) not moving livestock
5) installing chemical dips on farms to kill pathogens on footwear
6) spraying fungicides
7) vaccinating animals
56
what is athletes foot caused by?
parasitic fungi called dermatophytes
57
why does it usually occur on your feet?
they provide the perfect humid environment
58
what are the effects of athletes foot?
cracked, flaking and itchy skin
59
how can athletes foot be treated?
anti fungal cream
60
how is athletes foot spread?
it is contagiously spread thorough direct and indirect contact
61
what is food poisoning caused by?
caused by the growth of microorganisms in food - most serious type by bacteria and their toxins
62
what are the three main groups of food poisoning ?
1) campylobacter
2) salmonella
3) e.coli ( only some types)
63
what 3 things is campylobacter found in?
1) raw meat
2) unpasteurised milk
3) untreated water
64
what 4 things is salmonella found in?
1) raw meat
2) eggs
3) raw unwashed vegetables
4) unpasteurised milk
65
what 3 things is e.coli found in?
1) raw/under-cooked meat
2) unpasteurised milk
3) dairy products
66
how can you kill food poisoning bacteria?
cooking them
67
what are the 4 symptoms of food poisoning ?
1) stomach pains
2) diarrhoea
3) vomiting
4) fever
68
what are the three possible outcomes from food poisoning ?
1) quick recovery
2) use of a drip by a doctor
3) death
69
how are STIs spread?
thorough unprotected sex/ genital contact through bodily fluids or skin on skin contact
70
how can people protect themselves from STIs?
avoiding sex/ using condoms
71
what makes it easy for STIs to spread?
they initially have no symptoms
72
what type of infection is chlamydia?
bacterial
73
what type of infection is gonorrhoea?
bacterial
74
what type of infection is genital herpes?
viral
75
what type of infection is HIV?
viral
76
what are the 2 symptoms of chlamydia ?
1) pain when urinating
| 2) discharge from penis/ vagina
77
what are the 2 symptoms of gonorrhoea?
1) burning pain when urinating
| 2) vaginal discharge
78
what are the symptoms of genital herpes?
painful blisters/sores
79
what are the symptoms of HIV?
weakened immune system often resulting in AIDs
80
what is the treatment for chlamydia?
antibiotics
81
what is the treatment for gonorrhoea?
antibiotis
82
what is the treatment for genital herpes?
no cure
83
what is the treatment for HIV?
no cure but can be controlled with antiretoviral drugs and lifetime treatment is required
84
what is HIV?
a virus that invades white blood cells and reproduces inside the cells weakening the immune system
85
what does HIV do to the immune system?
it weakens it as the affected cells that should be producing antibodies can't
86
what is AIDs?
the final stage of HIV when the body can no longer fight disease and becomes the target of everyday infections/ cell changes causing cancer
87
how does tobacco mosaic virus effect plants?
causes leaves to be mottled/ discoloured by preventing chloroplasts from forming preventing the growth of plants
88
what does tobacco mosaic virus do to the yield of crops?
it never kills them but lowers their quality and quantity
89
how can you prevent the spread of plant viral disease?
removing infected plants and washing equipment between planting
90
how can you prevent re infecting soil with a virus?
planting crops that are resistant to tobacco mosaic virus in previously infected areas
91
what is an example of bacterial plant disease?
a. tumefaciens - a bacteria with causes crown gall disease
92
what is a. tumefaciens?
a bacterium with a large plasmid (aka tumour inducing plasmid) that contains genes that cause crown gall disease
93
how does a. tumefaciens enter a plant?
through a wound
94
what does a. tumefaciens cause to happne in the plant?
its plasmid integrates into the hosts genome causing the reproduction of greater amounts of growth chemicals than normal leading to the production of large tumour like galls
95
what happens as crown gall disease progresses?
the galls totally encircle the plants stem/trunk cutting of the flow of sap
96
what can crown gall disease cause?
stunted growth and eventual death
97
how can the spread of crown gall disease be prevented? 2 ways
1) destroying and removing infected plants
| 2) avoiding planting other susceptible plants in the area for two years until the bacteria die due to lack of host plant
98
what is an example of fungal plant disease?
powdery mildew
99
what is powdery mildew disease?
a fungal disease that affects a wide range of plants caused by many species of fungi
100
what does powdery mildew disease cause?
white powdery spots on the leaves and stems of the plant which reduces growth causing leaves to drop off early reducing the crop yeild.
101
how much does powdery mildew reduce crop yield by?
10 - 15%
102
where does powdery mildew grow best?
in areas of high humidity and moderate temperatures
103
where does powdery mildew survive between seasons?
on plant residues
104
how does powdery mildew spread?
it is released from spores which are spread by the wind to infect the new crop
105
how can powdery mildew be controlled?
by spraying the crop with fungicide
106
what are the two ways in which plants can protect themselves against communicable diseases?
physical and chemical defences
107
what are physical defences in plants?
physical barriers in plants that prevent microorganisms entering
108
what are chemical defences in plants?
substances secreted by the plant that kill microorganisms
109
what are 2 examples of physical defence in plants?
cuticles and cell walls
110
what cells are covered in waxy cuticle? where in the plant are they found?
epidermal cells which are in most parts on the plant above ground
111
what 2 things do the waxy cuticles prevent?
1) prevents water loss
| 2) prevent pathogens coming in direct contact with the epidermal cells limiting the chance of infection
112
what is the difference between the waxy cuticle layer on aquatic plants against that of a cactus
on aquatic plants the cuticle is thin but on cacus's it is thick
113
name the layers of a cross section of a leaf from top to bottom
1) waxy cuticle
2) epidermis
3) palisade layer
4) spongy layer
114
what about a cuticle prevents water collecting on the leaf surface?
its hydrophobic nature (water repelling)
115
why is the hydrophobic nature of cuticles important?
defence against fungal pathogens because most require withstanding water on the leaf surface for pore germination
116
what is the cell wall a major defence against?
fungal and bacterial pathogens
117
what do cell walls provide?
a structual barrier
118
what do all plant cells have? what does it provide?
primary cell wall providing structural support
119
what are primary cell walls made form? why?
cellulose fibres to give strength and flexibility
120
how are cells able to cement together?
by cross linking pectin and cellulose fibres gel is formed to glue neighbouring cells together
121
where does the secondary cell wall form? why is it needed?
develops inside some primary cell walls for further structural barriers
122
what do cell walls contain enabling them to detect pathogens?
contain chemical defences which can be rapidly activated
123
name 5 chemical defences of plants
1) insect repellents
2) insecticides
3) antibacterial compounds
4) anti fungal compounds
5) cyanide
124
what do insect repellents in plants do?
repel insect vectors that carry disease eg pine resin/ citronella from lemon grass
125
what do insecticides in plants do?
kill insects eg pyrethins made by chryanthemums
126
what do antibacterial compounds in plants do?
kill bacteria eg phenols that disrupt the bacterium's cell walls/ defensins which disrupt the cell membrane
127
what do anti-fungal compounds in plants do?
kill fungi eg caffeine which is toxic to insects/fungi / chitinases which are enzymes that break down the chitin in fungal cell walls
128
what does cyanide in plants do?
some plants make chemicals that break down to form cyanide if attacked which is toxic to most living things
129
what is diagnosis?
identifying a disease in a plant/ animal
130
what are the two ways which you can diagnose plant treatment?
observation and microscopy
131
what is observation of plant disease?
looking at the visual symptoms to find a diagnosis
132
give three examples of diseases that can be observed in plants
1) strawberry mottle disease
2) bacterial soft rot
3) powdery mildew
133
how can you observe to see if a plant has strawberry mottle disease?
looking for discolouration of the leaves in strawberry plants caused by a virus
134
how can you observe to see if a plant has bacterial soft rot?
looking for rotting in the leaves or fruit of a plant
135
how can you observe to see if a plant has powdery mildew?
looking for powdery white deposit on the plant and repeated fungal infection will weaken the plant/ reduce its yeild
136
why is microscopy sometimes vital in diagnosis of plant disease?
some symptoms are very similar so the pathogens need to be identified by their shape
137
what are 2 disadvantages when identifying plant diseases?
1) sometimes expensive electron microscopes are needle to correctly identify the pathogen
2) plant infections can only be identified in the fields once the infections symptoms have become apparent and the plants are infected
138
what two ways can plant disease be identified in the laboratory?
1) DNA analysis
| 2) identification of antigens
139
how does DNA analysis identify plant diseases?
all plant pathogens have unique genomes and scientists identify them through DNA fingerprinting
140
what does the map created by DNA analysis show and what is it called?
it shows the map of the pathogens genome and is known as the profile
141
how do scientists use DNA analysis to identify plant diseases?
by comparing unknown genomes map against a known DNA profile and if a match is found accurate diagnosis can be made
142
what specific things can DNA analysis be used to identify?
individual strains of a microorganism
143
what does chemical analysis identify?
the specific antigens carried on the surface of the pathogen
144
what have scientists developed to help farmers identify common crop pathogens?
diagnostic kits
145
what is the key advantage of laboratory based idnetification techniques?
you are able to identify the pathogen before it causes significant damage to the crop
146
what can happen if you cut/ graze your skin?
pathogens are able to enter your body
147
what does the body do when you cut yourself? why?
forms a scab to prevent pathogens entering our body and too much blood being lost
148
what are platelets? why are they needed?
fragments of cell made from bone marrow carried in the blood to help it clot
149
what are the 5 steps to forming a scab? i
1) skin is cut and starts to bleed - blood leaks out of body
2) platelets change the blood protein fibrinogen into fibrin forming a network of fibres in the cut
3) red blood cells are trapped in the fibres causing a blood clot
4) the clot hardens and thickens to form a scab keeping the skin clean and giving it time to heal
5) scab falls off
150
name 5 ways in which the body prevents microorganisms entering
1) skin
2) acid in stomach
3) cilia and mucus in airways
4) nasal hairs
5) tears
151
how does the skin prevent microorganisms entering the body?
it is a physical barrier with a dry dead outer layer which is difficult to penetrate and sweat glands produce oils that help kill microorganisms
152
how does the acid in the stomach prevent microorganisms entering the body?
kills pathogens in contaminated food/ drink
153
how does cilia and mucus in airways prevent microorganisms form entering the body?
sticky mucus traps the microorganisms and the cilia then move the mucus up the throat where it is swallowed
154
how do nasal hairs prevent microorganisms from entering the body?
they keep out dust and larger microorgansisms
155
how do tears prevent microorganisms entering the body?
they contain lysozyme enzymes which destroy bacteria
156
what are the two types of white blood cells in the immune system?
pagocytes and lymphocytes
157
what do phagocytes do?
engulf microorganisms and then make enzymes to digest the microorganisms
158
what do lymphocytes do?
make antitoxins and antibodies
159
what are antibodies?
proteins that bind to antigens on the surface of microorganisms
160
what happens white the antibodies bind to the antigens?
the pathogen is ingested by a phagocyte cell and then destroyed
161
why is the defence of antibodies specific?
because each antibody only binds to one type of antigen and therefore only one microorganism
162
what happens each time a new microorganism enters the body ?
a different lymphocyte makes a new antibody to fight it
163
what is immunity?
the ability for the body to be able to "fight off" a disease that has previously infected that body because the white blood cells are able to create the antibodies quickly again preventing them from causing the illness
164
how are monoclonal antibodies produced?
produced in the laboratory using special cells
165
what are the names of the three special cells used to create monoclonal antibodies?
hybridomas melanomas (cancer cells) and lymphocytes
166
why are they called monoclonal antibodies?
they are produced by a single clone of cells
167
what are monoclonal antibodies designed to do?
target a specific type of cell and bind to the antigens of target cells
168
what do monoclonal antibodies do to their target cells?
kill them or prevent them from operating effectively
169
how are GM mice used to produce monoclonal antibodies?
they are injected with the required antigen which causes their body to produce an immune response producing antibodies to the specific antigens
170
what do scientists collect from the GM mice once they have been injected with the correct antigens?
the antibody producing lymphocyte cells
171
what happens to the lymphocyte cells collected from GM mice? why?
they are fused with myeloma cells from bone marrow which reproduce infinitely because the lymphocytes cant survive outside the body
172
what is the name of the fused cell produced through combing cancerous cells and lymphocyte together?
hybridomia
173
what happens to hybridomia as it reproduces? why is this useful?
clones are created which produce the required antibody (monoclonal antibodies) which is harvested
174
name three situations when monoclonal antibodies used?
pregnancy testing, detecting disease, treating cancer
175
what hormone do women produce after becoming pregnant? when is it produced in the pregnancy?
hCG (human chorionic gonadotrophin) which is poduced two weeks after pregnancy
176
how are monoclonal antibodies used in pregnancy testing?
they are produced to bind to the hCG protein causing a colour changing reaction
177
how do home pregnancy tests work?
the short stick contains monoclonal antibodies so when urine containing hCG contacts the antibodies the colour changes indicating pregnancy
178
how are monoclonal antibodies used in detecting disease
some can act as marker by binding to a specific antigen to confirm its presence
179
give an example of when monoclonal antibodies have been used in medicine to identify disease
they have been developed to bind to the antigens of prostate cancer cells in men
180
why are monoclonal antibodies helpful to doctors when diagnosing and detecting disease?
it allows doctors to diagnose the disease at an early stage in order to get successful treatment
181
how are monoclonal antibodies used to treat cancer?
they target specific cells killing them or preventing them from operating effectively
182
how can monoclonal antibodies increase the effectiveness of cancer treatment?
they can carry drugs/ radioactive substances directly to radioactive caner cells and minimising damage to surrounding tissue
183
what 3 types of cancer can monoclonal antibodies be used to treat?
breast cancer, stomach cancer and bowel cancer
184
what are vaccines?
small amounts of weakened or dead pathogens inserted into the body via injection
185
what do vaccines do?
cause your lymphocyte cells to produce antibodies to the pathogen making you immune to the disease
186
how do vaccines make you immune?
it enables your body to respond quicker to the real pathogen if you get infected and remove them before causing disease
187
what are the 3 steps to vaccination ?
1) small amounts of dead/inactive pathogen inserted into body
2) antigens in the vaccine stimulate white blood cells to make antibodies which destroy the antigens without risk of you getting disease
3) you are now immune to that infection because your body can respond rapidly and make the correct antibody as if you already had the disease
188
what are the risks of vaccination?
occasionally a vaccination causes severe reaction and sometimes death
189
what has the UK child vaccination program lead to?
fewer children dying of infetious disease
190
what 6 diseases do children get immunised against between 2-4 months old?
1) polio
2) diphtheria
3) tetanus
4) whooping cough
5) Hib meningitis
6) meningitis C
191
what vaccination do children at 13 months old get? what three diseases does this vaccinate against?
MMR - measles mumps and rubella
192
what 5diseases do children between 3-5 years old get immunised against?
1) MMR
2) polio
3) diphtheria
4) tetanus
5) whooping cough
193
what disease do children between 10 and 14 years old get immunised against?
tuberculosis (TB)
194
what disease do girls between 12 and 13 years old get immunised against?
human papilloma virus (HPV)
195
what 3 disease do children between 13 and 18 years old get immunised against?
1) polio
2) diphtheria
3) tetanus
196
what are antiseptics?
treatment which kills or neutralises all types of pathogen but don't damage human tissue
197
what are disinfectants?
treatment which are applied to non living surfaces but can harm human tissue
198
what do different antiseptics act upon?
different microorganisms
199
what do most antiseptics kills?
bacteria as it is the most common source of infection
200
give two common examples of antiseptics
alcohol and iodine
201
what are antivirals?
drugs that destry viruses by preventing them from replicating
202
give three examples of infections antivirals are able to treat
HIV, herpies and hepatitus B
203
what are antivirals designed to do?
act upon one type of virus because they are specific
204
give 3 examples of what activity of an antiviral drug
1) blocking the virus from entering a host cell
2) preventing the virus from relaesing genetic material
3) preventing the virus from inserting its genetic data into the host cells DNA
205
what are antibiotics?
drugs that kill bacteria without damaging cells and have no effect n fungus or viruses
206
what do different types of antibiotic do?
kill different types of bacteria
207
how do scientists identify which antibiotics you need?
by sending blood or stool samples to a lab where they are grown on agar plates which are then treated with different antibiotics and the patient would be treated with the most effective drug
208
what is the zone of inhibition?
the area on an agar plate where bacteria cant grow
209
what does aseptic mean?
"without microorganisms"
210
what is aseptic tehnique?
a technique used to ensure no foreign microorganisms are introduced into a sample being tested ensuring the envrionment remains sterile
211
what does streile mean?
environment free of microorganisms
212
what are the 4 different ways you can ensure aseptic technique ?
1) washing working areas with alcohol before and after working
2) wearing gloves if at risk with pathogens
3) autoclave glassware and apparatus before after use
4) working close to a Bunsen burner flame
213
how does washing working areas with alcohol before and after working ensure aseptic technique?
it ensures no microorganisms are present in the working area
214
how does wearing gloves if at risk with pathogens ensure aseptic technique?
it prevenst microorgansisms pasing from the sample to the skin
215
how does using autoclave on glassware and apparatus before after use ensure aseptic technique ?
it sterilises the apparatus preventing unwanted contamination of a sample
216
how does working close to a Bunsen burner ensure aseptic technique ?
it prevents unwanted microorganisms from falling into an open sample
217
how are microorganisms usually transferred from one medium to another using aseptic technique?
a wire loop that is streilised
218
how do you sterilise the loop needed to transfer microorganisms in aseptic technique?
heat the loop in a Bunsen burner until it glows red and then cool before use but while cooling hold it close to the flame and away from the bench to keep it sterile
219
what are the two ways in which new drugs are created?
from plant extracts and from being made in the laboratory
220
what do scientists use to develop possible drugs?
computer modelling software
221
how does computer modelling software enable scientists to create new drugs?
the software produces a list of compounds that may target a particular condition
222
what do scientists do when they find a potentially useful substance fro a new drug?
perform laboratory tests to find out how it behave
223
give examples of laboratory tests that scientists would carry out on possible substances for new drugs
tests on live cells/ bacteria/ tissue cultures
224
what is preclinical testing
drug testing that happens before it is tried out on living organism
225
what usually happens at preclinical testing?
the drugs fail as they damage cells or don't work
226
what are the two stages of dug testing ?
1) testing on animals
| 2) testing on humans
227
what needs to happen in animal drug testing before it can be tested on humans?
it has to be sucessfully tested on two species of animal befre it can be tested on humans
228
what is the name for testing on humans?
clinical trials
229
what are the three stages of clinical trials?
1) drug tested o healthy volunteers
2) drug tested on a small sample of volunteers
3) drug tested on large number of people
230
why are new drugs tested on healthy volunteers?
to look for unexpected side effects
231
why are new drugs tested on a small group of volunteers
to see how effective the drug is on a few hundred with the condition
232
why are new drugs tested on large groups of volunteers?
to see how well the drug works and check it is safe for everyone in this group of a few thousand people
233
what is monitored when testing new drugs on large groups of people?
effectiveness, safety ,dosage and side effects
234
what happens if the new drugs pass all the tests?
it is approved for use
235
what happens once a new drug is approved?
re any unexpected side effects or if it causes problems to certain types of people studies continue to monitor the drug to see if there are any unexpected side effects or if it causes problems for certain groups of people
236
what is a placeb effect?
where people feel better because they expect to feel better as a result of taking medicine
237
how are placebo effects overcome in linical trials?
researchers use double blind trials where some patients get the drug while others get a replica of the drug and neither doctors or patients know which drug is the placebo
238
what are the three Rs scientists are encouraged to follow when testing on animals?
reduction, refinement and replacement
239
what does replacement mean in terms of the 3Rs?
replacing the use of animals where possibel with other techniques
240
what culd scientis use instead of animals in drug testing?
cell cultures and computer models
241
what is reduction in terms of the 3Rs?
using the smallest amount of animals as possible eg scientists share results of research
242
what is refinement in terms of the 3Rs?
improving experiments t avoid unnecessary suffering and improve the way animals are cared for
243
what two thigs increase the chances of developing non communicabel diseases?
smoking and drinking alcohol
244
what 5 harmful substances does tobacco contain?
1) tar
2) nicotine
3) carbon monoxide
4) particulates
5) their substances
245
what is harmful about tar in tobacco?
it collects in the lungs when the smoke cools and is carcinogenic (can cause cancer)
246
what is harmful about nicotine in tobacco?
it is an addictive drug affecting the nervous system making the heart beat faster and blood vessels narrow
247
what is harmful about carbon monoxide in tobacco?
it is a poisonous gas that attaches to the haemoglobin in red blood cells in place of oxygen causing the heart to have to work harder as there is less oxygen in the blood which can lead to heart disease
248
what is harmful about particulates?
they are small pieces of sold which are engulfed by white blood cells causing an enzyme to be released which weakens the alveoli meaning they don't inflate properly when a person inhales so less oxygen passes into the blood making them breathless
249
what disease is caused by particulates in tobacco?
emphysema
250
what is harmful about other substances in tobacco ?
hey paralyse the ciliated cells lining the airways allowing mucus into the lungs which can cause infections such as bronchitis
251
what drug does alcohol contain?
ethanol
252
what type of drug is ethanol?
it is a depressantcausing the nerous sytem to slow down
253
what effects can alcohol have upon people?
feeling happy/ relaxed or aggressive or sad
| blurred vision/ loss of balance and increase reaction time
254
what does the liver do to ethanol?
breaks it down into waste products which are excreted from you body as ethanol is toxic
255
hat happen to the livers of heavy drinkers?
they become scarred
256
what is crirrhosis?
where healthy cells are replaced with fat or fibrous tissue causing the liver to be less effective which can be fatal
257
what can heavy drinking cause over months and years?
stomach ulcers, heart disease, brain damage (memory loss/ depression)
258
what is cardiovascular disease (CVD)?
a general term to describe a disease of the heart or blood vessels
259
what is atherosclerosis
the hardening or narrowing of the arteries which reduces blood flow to the heart/brain /body due to a build up of fatty deposits
260
what is thrombosis?
blood clot causing CVD
261
what 2 things can thrombosis cause?
1) if it happens in an artery supplying a heart muscle it can cause heart attack
2) if it occurs in an artery in the brain it can cause a stroke
262
what 4 things can increase the risk of CVD?
1) poor diet - too much flt/ saturated fats
2) little exercise
3) smoking - carbon monoxide causes increase in blood pressure
4) high blood pressure - can damage blood vessels
263
how does too much salt increase the risk f CVD?
it causes more water to be absorbed back into the blood flowing filtration of the kidney and the extra water causes high blood pressure
