Disease Flashcards
(109 cards)
1
Q
What is health?
A
The state of physical and mental wellbeing
2
Q
What are communicable diseases?
A
Diseases that can be spread from person to person or between animals and people. They can be caused by pathogens and can be described as contagious or infectious. Examples include measles and malaria
3
Q
What are non-communicable diseases?
A
Diseases that cannot be spread between people or between animals and people. They generally last for a long time and get worse slowly. Example include asthma
4
Q
What’s the problem with a weak immune system?
A
You have an increased chance of suffering from communicable diseases (e.g. the flu) because the body is less likely to be able to defend itself against the pathogen that causes the disease
5
Q
What can some types of cancer be triggered by?
A
Infection by certain viruses
E.g. the hepatitis virus can cause long-term infections in the liver which increases the chance of getting liver cancer. Also, infection with HPV can cause cervical cancer
6
Q
What are asthma sufferers in danger of?
A
Their symptoms becoming worse - immune system reactions in the body caused by infection by a pathogen can trigger allergic reactions (e.g. skin rashes) or worsen the symptoms of asthma
7
Q
How can be mental health problems be triggered?
A
When someone is suffering from severe physical body problems, especially if they have an impact on their ability to do normal activities or affect their life expectancy
8
Q
What are risk factors?
A
Things that are linked to an increase in your chance of contracting a disease
E.g. smoking, obesity, drinking, exposure to radiation
9
Q
Smoking as a risk factor
A
Causes cardiovascular disease, lung disease and lung cancer. It damages the walls of arteries and the cells in the lining of the lungs
10
Q
Obesity as a risk factor
A
Causes Type 2 diabetes - makes the body less sensitive to insulin
11
Q
Drinking as a risk factor
A
Drinking too much alcohol causes liver disease, affects brain function and damages the nerve cells in the brain
12
Q
Exposure to radiation as a risk factor
A
Cancer can be caused by exposure to ionising radiation, a carcinogen (something that causes cancer)
13
Q
What are benign tumours?
A
Tumour grows until there’s no more room
The tumour stays in once place (usually in a membrane)
Isn’t dangerous or cancerous
14
Q
What are malignant tumours?
A
Tumours grow and spread to nearby healthy tissues - invading these tissues forms secondary tumours
Cells can break off and spread to other parts of the body via the bloodstream
Is dangerous and cancerous - can be fatal
15
Q
Risk factors for cancer
A
Smoking - lung, mouth, bowel, stomach and cervical cancer
Obesity - bowel, liver and kidney cancer
UV exposure - skin cancer
Viral infection - infection with hepatitis B/C can increase the risk of developing liver cancer
16
Q
Epidermal tissue
A
Covers the whole plant
17
Q
Palisade mesophyll tissue
A
Where most photosynthesis happens
18
Q
Spongy mesophyll tissue
A
Contains big air spaces to allow gases to diffuse in and out of cells
19
Q
Meristem tissue
A
Found at the growing tips of roots and shoots
Able to differentiate into lots of different types of plant cell - allows the plant to grow - plant stem cell
20
Q
Waxy cuticle
A
Reduces water loss via evaporation
21
Q
Upper epidermis
A
Transparent so light can pass through it to reach the palisade layer
22
Q
Palisade layer
A
Contains chloroplasts - where photosynthesis takes place
Located near the top of the plant to absorb as much sunlight as possible
Large surface area with chloroplasts packed tightly together
23
Q
Stomata
A
Little holes in the lower epidermis that allow carbon dioxide to diffuse into the leaf
24
Q
Guard cells
A
Control the opening and closing of the stomata
They don’t open up at night as there is no sunlight
25
Phloem
Made up of elongated living cells
Transports food substances made in the leaves to the rest of the plant for immediate use or storage
Transport food substances in both directions - translocation
26
Xylem
Made up of dead cells
Transports water and mineral ions from the roots to the stem and the leaves
Transports them one way only
Movement of water from the roots, through the xylem and out of the leaves is called transpiration
27
What is transpiration?
The loss of water from plants by evaporation
Water evaporates from the leaves
Side effect of photosynthesis
28
How does light intensity affect transpiration?
The brighter the light, the greater the rate
In bright light, the stomata will stay open for longer
29
In bright light
the stomata will stay open for longer
30
How does temperature affect transpiration?
The warmer it is, the faster the rate
The hotter it gets, the more kinetic energy the water molecules gain
31
How does air flow affect transpiration?
The better the air flow around a leaf
A good air flow will sweep water vapour away which maintains a low concentration gradient of water in the air outside the leaf
Diffusion happens quicker from an area of high concentration to an area of low concentration
32
How does humidity affect transpiration?
The drier the air around a leaf, the faster the rate
Humid air contains lots of water, so the lower the humidity, the faster diffusion will take place
33
How are guard cells adapted to open and close stomata?
When the plant has lots of water, they fill with water and become turgid - opens the stomata
When the plant is short of water, they lose water and become flaccid - closes the stomata
Thin outer walls and thicker inner walls control the opening and closing
Sensitive to light so they close at night
34
What is a pacemaker?
A group of cells in the right atrium wall that control the resting heart rate
They produce a small electrical impulse which spreads to the surrounding muscle cells, causing them to contract
Artificial pacemakers can be used to control heartbeat if the natural pacemaker cells don't work well e.g. irregular heartbeat - they are little devices implanted under the skin and have a wire going to the heart - they produce an electric current to keep the heart beating regularly
35
Investigation into the Effect of pH on Enzyme Activity - Method
1) Put a drop of iodine solution into every well of a spotting tile
2) Place a Bunsen burner on a heatproof mat, & a tripod & gauze over the Bunsen burner. Put a beaker of water on top of the tripod & heat the water until it is 35°C - keep the temperature of water constant throughout the experiment
3) Use a syringe to add 1cm³ of amylase solution and 1cm³ of a buffer solution with a pH of 5 to a boiling tube. Using test tube holders, put the tube into the beaker of water & wait for 5 minutes
4) Next, use a different syringe to add 5cm³ of a starch solution to the boiling tube
5) Immediately mix the contents of the boiling tube & start a stopwatch
6) Use continuous sampling to record how long it takes for the amylase to break down all of the starch - use a dropping pipette to take a fresh sample from the boiling tube every 30 seconds & put a drop into a well. When the iodine solution stays browny-orange, starch is no longer present
7) Repeat the experiment with the buffer solutions of different pH values to see how pH affects the time taken for the starch to be broken down
36
Calculation - Rate of Reaction
Rate = 1000/time
37
Benedict's Test - testing for sugars
1) Prepare a food sample & transfer 5cm³ to a test tube
2) Prepare a water bath so that it's set to 75°C
3) Add some Benedict's solution to the test tube (about 10 drops) using a pipette
4) Place the test tube in the water bath using a test tube holder & leave it there for 5 minutes. Ensure the tube is pointing away from you
5) If the food sample contains a reducing sugar, the solution in the test tube will change from the normal blue colour to green, yellow or brick-red - depends how much sugar is in the food
38
Iodine Solution - testing for starch
1) Make a food sample & transfer 5cm³ of it to a test tube
2) Add a few drops of iodine solution & gently shake the tube to mix the contents - if the sample contains starch, the colour of the solution will change from browny-orange to blue-black
39
Biuret Test - testing for proteins
1) Prepare a sample of your food & transfer 2cm³ of it to a test tube
2) Add 2cm³ of biuret solution to the sample & mix the contents of the tube by gently shaking it
3) If the food sample contains protein, the solution will change from blue to pink or purple
40
Sudan III Test - testing for lipids
1) Prepare a sample of the food you're testing & transfer 5cm³ into a test tube
2) Use a pipette to add 3 drops of Sudan III stain solution to the test tube & gently shake the tube
3) The solution stains lipids, therefore if the mixture contains lipids, it will separate out into two layers - the top layer will be bright red
41
What is a catalyst?
A substance which increases the speed of a reaction, without being changed or used up in the reaction
42
Big Molecules
Starch
Proteins
Fats
43
Small Molecules
Sugar
Amino acids
Glycerol
Fatty acids
44
What is a double circulatory system?
Two circuits joined together.
Humans have one
45
What are coronary arteries?
Arteries that branch off the aorta & surround the heart, ensuring that it gets all the oxygenated blood it needs
46
Human Cost of Disease
1) Millions of deaths
2) Lower quality of life
3) Shorter lifespan
4) Effect of disease spreads to family members & relatives
47
Financial Cost of Disease
1) Cost to the NHS of researching & treating these diseases is huge
2) Families may have to move or adapt their home to help a family member with a disease
3) If a family member has to give up work or dies, the family's income will be reduced
4) Reduction in the number of people able to work can also affect a country's economy
48
Why is the mean rate of water uptake higher on a hot day?
Water molecules will have more kinetic energy, thus they'll be released from the stomata by transpiration faster
The roots will need to absorb more water to replace the large amounts of water lost from evaporation
49
How does the movement of potassium ions into the guard cells cause the stoma to open?
1) Ions increase the concentration of the solution
2) Water moves into the guard cells by osmosis
3) The cell swells unevenly due to having a thicker inner wall & a thinner outer wall
50
How does amylase break down starch?
1) The starch substrate fits into the active site of the amylase to form a complimentary shape
2) The bonds in the substrate are broken to form two smaller substrates
51
How do viruses make you ill?
They invade healthy cells and replicate inside them.
The cells will burst and release all the copies of the virus
52
What are protists?
Single-celled eukaryotes
53
What are parasites?
Protists that live in or inside other organisms and cause damage. They are transferred by a vector
54
How can pathogens be spread?
1) Water - drinking/bathing in dirty water e.g. cholera
2) Air - breathing it in or the spreading of droplets from coughs or sneezes e.g. the flu
3) Direct contact - touching contaminated surfaces e.g. athlete's foot
55
Measles
Virus spread by droplets from a sneeze or a cough
Symptoms: red skin rash and a fever
It can sometimes lead to pneumonia or encephalitis (a brain infection)
Can be vaccinated against
56
HIV
Virus spread by sexual contact or by exchanging bodily fluids e.g. sharing needles when taking drugs
Symptoms: flu-like symptoms for a few weeks
Antiretroviral drugs stop the HIV virus replicating
The virus attacks immune cells
If the immune system is badly damaged, it can't cope with other infections or cancer - the virus at this stage is known as AIDS
57
Tobacco Mosaic Virus (TMV)
Virus that affects many species of plants e.g. tomatoes
Symptoms: a mosaic pattern on the leaves - parts of the leaves become discoloured
The discolouration prevents the plant from photosynthesising as well, thus the virus affects growth
58
Rose Black Spot
Fungus that causes purple/black spots to appear on leaves of rose plants - the leaves then turn yellow and fall off
Inhibits the process of photosynthesis and growth
Spread via the environment e.g. water or wind
Treatment: fungicides and stripping the plant of its affected leaves and then burning the leaves so the virus doesn't spread
59
Malaria
Caused by a protist
Mosquitoes are vectors that acquire the malarial protist from feeding on infected animals
Each time a mosquito feeds on another animal, it infects it by inserting the protist into the blood vessels
Symptoms: repeating episodes of fever - can be fatal
Insecticides and mosquito nets help prevent malaria
60
Salmonella
Bacteria that causes food poisoning by producing toxins
Symptoms: fever, stomach cramps, vomiting and diarrhoea
Caused by eating food contaminated with salmonella e.g. uncooked chicken
In the UK, most chickens are vaccinated against salmonella
61
Gonorrhoea
Bacterial disease
Sexually transmitted disease (STD) caused by sexual contact e.g. unprotected sex
Symptoms: pain when urinating; thick yellow/green discharge from the vagina/penis
Originally treated with penicillin - now some strains have become resistant to it
Treatment with antibiotics and using barrier methods of contraception (e.g. condoms) help prevent the spread of it
62
Reducing/Preventing the spread of diseases
1) Being hygienic e.g. washing hands before preparing food or after sneezing
2) Destroying vectors e.g. vectors that are insects are killed by insecticides or destroying their habitats
3) Isolating infected individuals e.g. quarantine for people with communicable diseases
4) Vaccination - vaccinating against communicable diseases stops them from being developed then passed on
63
What is a vector?
Organisms that spread disease, they trap particles that contain pathogens
64
The skin as a defence
Acts as a barrier to pathogens
Secretes antimicrobial substances which kill pathogens
65
Hairs and mucus as a defence
In your nose, they trap particles that contain pathogens
66
The trachea & bronchi as a defence
Secrete mucus which traps pathogens
67
Cilia as a defence
Hair-like structures which waft the mucus up to the back of your throat where it can be swallowed (and used to trap pathogens)
68
The stomach as a defence
Produces hydrochloric acid which kills pathogens that make it farther than the mouth
69
Phagocytes - white blood cells
Engulf foreign cells (microbes etc) and digest them
70
B-lymphocytes - white blood cells
Recognise foreign antigens on cells and produce antibodies to lock onto the antigens so that the cells can be located and destroyed
The antibodies are specific to that type of antigen - they form a lock and key connection
71
T-lymphocytes - white blood cells
Produce antitoxins that neutralise any toxins produced by bacteria
72
What are antibodies?
Y-shaped proteins that are produced by B-lymphocytes
73
Vaccinations
Injecting small amounts of dead or inactive pathogens into a person's bloodstream. The pathogens carry antigens which triggers the immune system to produce antibodies to attack them. This helps the immune system to recognise the real pathogen and destroy it quicker and more efficiently
74
PROS of vaccinations
1) Helped to control many communicable diseases that were once common in the UK e.g. polio
2) Epidemics can be prevented if a large percentage of the population have been vaccinated - therefore, fewer people are likely to spread the disease
75
CONS of vaccinations
1) Sometimes they don't give you immunity
2) They can sometimes trigger bad reactions e.g. swelling, fevers, seizures - bad reactions are very rare
76
What are painkillers?
Drugs that relieve the pain and help reduce the symptoms of a disease
77
What are antibiotics?
Drugs that kill or prevent the growth of bacteria without killing healthy body cells
78
What is the problems with antibiotics?
Bacteria can mutate and become resistant to an antibiotic
79
What is the problem with a resistant strain of bacteria?
It could cause a serious infection that cannot be treated with antibiotics e.g. MRSA causes serious wound infections and is found in people's noses
80
Drug testing - Stage 1
Drugs are tested on human cells and tissues
However, human cells and tissue won't determine a drug's effectiveness against an entire body system
81
Drug testing - Stage 2
Drugs are tested on live animals - at least two different mammals
Tests for efficacy (whether it works), toxicity (how harmful it is) and to determine the right dosage
82
Drug testing - Stage 3
Drugs are tested on human volunteers
1) Drug is tested on healthy volunteers at a low dosage - reveals any harmful side effects
2) Drug is tested on the sick people it is designed to treat - used to find the optimum dosage
3) The patients are randomly sorted into 2 groups - one group gets a placebo, the other gets the actual drug
83
Why do plants need mineral ions?
If there aren't enough of them, the plants will suffer from deficiency symptoms
84
What are nitrates needed for?
To make proteins
85
What are magnesium ions needed for?
To make chlorophyll
A lack of magnesium causes chlorosis and yellow leaves
86
Common symptoms of plant diseases
1) Stunted growth
2) Abnormal growths e.g. lumps
3) Spots on the leaves
4) Malformed stems or leaves
5) Patches of decay (rot)
6) Discolouration
87
Physical defences of plants
1) Waxy cuticle - provides a barrier to prevent pathogens from entering
2) Cell walls - form a physical barrier against pathogens that get past the waxy cuticle
3) Layers of dead cells - found around stems that act as a barrier to pathogens
88
Chemical defences of plants
1) Antibacterial chemicals - these kill bacteria and are found in mint plants and witch hazels
2) Poisons helped to deter herbivores from eating them e.g. tobacco plants, foxgloves and deadly nightshade
89
Mechanical defences of plants
1) Thorns or hairs - prevent animals from touching or eating them
2) Leaves that droop or curl when something touches them - help to knock insects off the leaves and prevent them from eating the plant
3) Mimicking other organisms e.g. the passion flower has bright yellow spots which resemble butterfly eggs - prevents other butterflies laying their eggs there
90
How do bacteria make us feel ill?
Producing toxins that damage cells and tissues
91
Aspirin
Used as a painkiller & to lower fever
Developed from a chemical found in willow
92
Digitalis
Used to treat heart conditions
Developed from a chemical found in foxgloves
93
Why are some patients given a placebo?
It acts as a control - to see if the drug given to the other group was actually effective
94
What are monoclonal antibodies?
Produced from lots of clones of a single white blood cell
They're all identical & will only target one specific protein antigen
95
What factors can affect you health?
1) Balanced diet - provides your body with everything it needs
2) Stress - being constantly under lots of stress can lead to health issues
3) Life situation - having easy access to medicine or things that can prevent illness e.g. buy healthy food or condoms to prevent catching an STD
96
What is a hybridoma cell?
The fusion of a mouse B-lymphocyte with a tumour cell
They can be cloned lots to get lots of identical cells - these cells all produce the same (monoclonal) antibodies which can be collected & purified
97
What is HCG?
Human Chorionic Gonadotropin
A hormone found in the urine of women only when they're pregnant
98
Pregnancy Test - Process
1) The bit of the stick you wee on has some antibodies to the HCG hormone, with blue beads attached
2) The test strip has some more antibodies to the hormone stuck onto it
3) If you're pregnant & you wee on the stick:
-The hormone binds to the antibodies on the blue beads
-The urine moves up the stick, carrying the hormone & the beads
-The beads & hormone bind to the antibodies on the strip
-The blue beads get stuck on the strip, turning it blue
4) If you're not pregnant & you wee on the stick, the urine still moves up the stick, carrying the blue beads - since there's nothing to stick the blue beads onto the test strip, it doesn't go blue
99
What are tumour markers?
Antigens on the cell membranes of cancer cells that aren't found on normal body cells
100
What can an anti-cancer drug be?
1) A radioactive substance
2) A toxic drug
3) A chemical which stops cancer cells growing & dividing
101
How are monoclonal antibodies used to treat cancer?
They're attached to an anti-cancer drug which is given to the patient via a drip. The antibodies target the specific cancer cells as they only bind to tumour markers. The cancer cells are killed but the normal body cells are left untouched
102
What can monoclonal antibodies be used for?
1) Binding to hormones & other chemicals in blood to measure their levels
2) Testing blood samples in laboratories for certain pathogens
3) Locating specific molecules on a cell or in a tissue
103
How are monoclonal antibodies used to locate specific molecules on a cell or in a tissue?
1) Monoclonal antibodies are made that will bind to the specific molecule
2) The antibodies are then bound to a fluorescent dye
3) If the molecules are present in the sample being analysed, the monoclonal antibodies will attach to them - they can be detected using the dye
104
Problems of Monoclonal Antibodies
1) They have side effects e.g. fever, vomiting & low blood pressure
2) They're not as widely used as treatments due to the many side effects they have
105
Fungi
Some fungi are single-celled
Other fungi have a body which is made up of hyphae - these grow & penetrate human skin & the surface of plants
Hyphae can produce spores - can spread to other plants & animals
106
How can you identify a plant disease?
1) Looking up the signs in a gardening manual or on a gardening website
2) Taking the infected plant to a laboratory - scientists can identify the pathogen
3) Using testing kits that identify the pathogen using monoclonal antibodies
107
Why are some patients given a placebo?
It acts as a control - to see if the drug given to the other group was actually effective
108
What does a lack of magnesium cause in plants?
Chlorosis
109
