B3 Infection And Response Flashcards
What is a pathogen?
Microorganisms that enter the body and cause disease
Define Communicable Disease
Diseases that can be spread from person to person or between animals and people.
Define Non-Communicable Disease
Diseases that can not be spread from person to person or between animals and people.
What are the four pathogens and what type of organism are they?
Bacteria - prokaryotic cells
Virus - 1/100th of the size of bacteria - not cells (little machines)
Protists (includes parasites) - eukaryotic cells
Fungi - cells
What are the three main ways that pathogens spread?
Water,
Air,
Direct contact.
Name 3 viral diseases
Measles,
HIV,
Tobacco mosaic virus (TMV)
How is Measles transmitted?
Droplets from an infected person’s sneeze or cough.
How is HIV transmitted?
Sexual contact or exchanging of bodily fluids.
What happens to people with Measles?
Develop a red rash
Show signs of fever
Can cause complications (pneumonia - lungs, or encephalitis - brain)
What happens to people with HIV?
Flu-like symptoms
Damages the immune system
What happens to plants infected with TMV (Tobacco mosaic virus)?
Mosaic patterns on leaves
Discolouration of leaves
Can not carry out photosynthesis
Name a Fungal Disease which affects plants
Rose Black Spots
How can Rose Black Spots be treated?
Using fungicides and stripping infected leaves
What happens to plants with Rose Black Spots?
Their leaves get black or purple spots so they can not photosynthesise. They then turn yellow and fall off.
What plants are affected by Rose Black Spots?
Rose leaves!!
well nah!
Name a Disease caused by a protist
Malaria
What species are vectors for malaria?
Mosquitos
What is a vector (in terms of protists)?
An organism which carries a parasite without getting the disease itself
How do we prevent the spread of malaria?
Using insecticides and mosquito nets to avoid getting bitten
What happens to people with Malaria?
Repeating episodes of strong fever
Can be fatal
Name two Bacterial Diseases
Salmonella and Gonorrhoea
What happens to people with Salmonella?
Fever, Stomach cramps, Vomiting and Diarrhoea
How can you get Salmonella?
Food Poisoning
You get Salmonella when you eat contaminated foods that has caught the disease either when it was alive or by being prepared in unhygienic conditions
How can you get Gonorrhoea?
Gonorrhoea is an STD (sexually transmitted disease) meaning it is transmitted through un-protected sex
What happens to people with Gonorrhoea?
Pain when urinating
Thick, yellow or green discharge from the vagina or penis
How can we prevent Salmonella?
Good hygiene when cooking and cooking food thoroughly
We can also vaccinate poultry
How can we prevent Gonorrhoea?
Condoms and other barrier contraception
What are the four main ways of reducing the spread of communicable disease?
Being Hygienic
Destroying vectors
Isolating infected individuals
Vaccinations
Define Primary Defence
First line of defence against pathogens
skin, earwax
Define Secondary Defence
Second line of defence against pathogens, incase they get past the primary defence
(white blood cells)
How is skin specialised to protect against pathogens?
Acts as a barrier
Has antimicrobial substances
How are hair and mucus in the nose specialised to protect against pathogens?
They trap particles containing pathogens.
How are the trachea ad bronchi specialised to protect against pathogens?
Secrete mucus to trap pathogens
Lined with hair-like cilia which waft this mucus to the back of the throat to be swallowed
How is the stomach specialised to protect against pathogens?
Produces hydrochloric acid to kill pathogens that enter the body
What is the function of white blood cells?
Fight infection
What are the three ways white blood cells fight infection?
Engulfing pathogens
Producing antibodies
Producing antitoxins
What is the name given to the process by which white blood cells engulf pathogens?
Phagocytosis
What do vaccinations contain?
Dead or inactive form of a pathogen
What is the function of vaccines?
Preventing diseases
How do vaccines work?
Dead or inactive forms of a pathogen are put into the bloodstream
The white blood cells detect antigens on their exterior and produce antibodies to fit them
In future, if infected, the white blood cells will know exactly how to deal with the invasion and will react quickly
What are the negatives of vaccinations
Don’t always work
Could have a bad reaction
What drug would help kill bacterial pathogens that have infected the body?
Antibiotics
What are the functions of cold remedies and painkillers?
To ease the symptoms of a disease
They DO NOT kill the pathogen or tackle the cause
Would you treat a cold or flu with antibiotics?
No as they are viruses, it is very difficult to create drugs for these without damaging the body cells
What does it mean if bacteria become resistant to an antibiotic?
They mutate to resist the effects of this bacteria
How can we avoid bacteria becoming resistant to antibiotics?
Not over-prescribing them
Finishing full courses of antibiotics
What was aspirin developed from?
A chemical in willow
What was digitalis developed from?
A chemical in foxgloves
What is aspirin?
A common painkiller
What is digitalis?
A medicine used to treat heart conditions
What was penicillin developed from?
A mold on a petri dish
Who discovered penicillin?
Alexander Fleming
What are the three stages of drug testing?
Testing on human cells and tissues
Testing on animals
Testing on human volunteers
What are most drugs derived from?
Plants
Microorganisms
Why must we test on organisms after trials on human cells and tissues?
We do not get an understanding on how the drug works in an organ system
What do we attempt to understand when we test new drugs on animals?
To understand how it works in a system
To test efficacy (has the desired effect)
To calculate the dosage
To understand the toxicity
Why must we test on healthy volunteers before those with the disease?
To see how the body reacts in a healthy immune system
What is a placebo?
A substance that seems like the drug being tested but doesn’t actually do anything (sugar pill)
Why do we test a group of infected people as well as a placebo group?
To ensure we take out the development of the disease and the placebo effect from the experiment
Describe the placebo effect
When you are given something (such as a drug) and because you think it works, you begin to feel better
What is a blind trial?
The patients do not know if they have the placebo or not but doctors do
What is a double-blind trial?
Neither patients nor doctors know who has the placebo
Why are double-blind trials generally more reliable than blind trials?
The doctors will not dismiss or over-invest in any patients and will take every patients inquiry the same as they will not be sub-consciously influenced by the knowledge of who has the real drug
What types of white blood produce antibodies?
B-lymphocytes
What are monoclonal antibodies?
Antibodies cloned in a laboratory
What are hybridoma?
A tumour fused with B-lymphocytes
These mean that the B-lymphocytes multiply and create monoclonal antibodies faster
How can we use Monoclonal antibodies in pregnancy tests?
HCG is found in the urine of pregnant women
A pregnant woman pees on a stick which has antibodies to the hormones
If they link to the hormone the test shows pregnant and if they don’t it shows not pregnant
Why do the same monoclonal antibodies not work for everything?
Each antibody targets a specific chemical or cell
What is an advantages to using monoclonal antibodies for cancer treatment?
Unlike other treatments, they target specific cells and thus do not harm the rest of the body
What is a disadvantages to using monoclonal antibodies for cancer treatment?
Have more side effects than was first expected-
fever
vomiting
low blood pressure
What do plants need nitrate ions for?
They are needed to make proteins and therefore for growth
What do plants need magnesium ions for?
They are used to make chlorophyll for photosynthesis
What happens to plants who do not have enough nitrate ions?
Stunted growth
What happens to plants who do not have enough magnesium ions?
Suffer from chlorosis and have yellow leaves
What are 6 signs that a plant has a disease?
Discolouration Stunted growth Spots on leaves Abnormal growths Patches of decay (rot) Malformed stems/leaves
What are cell walls made of?
Cellulose
What barrier defence do plants have?
Waxy Cuticle (and epidermis) Layer of dead cells around the stem
Describe three mechanical defences of plants
Thorns/ Hairs
Mimic other organisms
Droop/Curl when touched
