B3 Flashcards
What is a pathogen?
A microorganism that enters the body and causes disease
How do bacteria make you feel ill?
They produce toxins that damage your cells and tissues
How do viruses cause disease?
They produced rapidly inside cells and the cell will burst releasing all the new viruses into the rest of your body
What in viruses make you feel ill?
The cell damage they cause
How can pathogens be spread?
Through water air and direct contact
What are the three viral diseases needed to know?
Measles, HIV tobacco mosaic virus
What is measles?
A red skin rash that also has signs of a fever
How do people prevent themselves from getting measles?
The measles vaccine when they are young
What is HIV?
If virus spread by sexual contact or exchange of bodily fluids
What does HIV do to the body?
Attacks immune cells
What is TMV?
A virus that occurs in plants and leaves plants discoloured
What does the discolouration in plants mean for them?
They can no longer carry out photosynthesis as well, so it affects the growth of the plant
What fungal disease is needed to be known?
Rose black spot
What is Rose black spot?
Black spots appear on plants and the leaves will turn yellow and drop off
How does rose black spot affect the plant?
Photosynthesis can no longer occur as much so the plant doesn’t grow very well
How is Rose black spot spread?
Through the environment in the wind and the water
What is the disease caused by a protest that is needed to be known?
Malaria
What is malaria?
The disease that causes repeating episodes of fever
How do human/animals contract malaria?
Is carried through a mosquito and the mosquito feeds on another animal and infecting it by inserting the protist into the animals blood vessels
How can the spread of malaria be stopped?
Mosquito nets and the stopping of mosquitoes breedimg
What bacterial diseases are needed to be known?
Salmonella and gonorrhoea
What is salmonella?
A type of bacteria that causes food poisoning
What are the symptoms of salmonella?
Fever, stomach cramps, vomiting, and diarrhoea
How is the spread of salmonella controlled?
Chickens are given a vaccination against salmonella
What is gonorrhoea?
Sexual transmitted disease that are passed on by sexual contact
What are the symptoms of gonorrhoea?
Pain when they urinate and yellow or green discharge from the vagina or penis
How can the spread of gonorrhoea be treated?
By using methods of contraception such as condoms or treated with antibiotics
How can the spread of disease be reduced or prevented?
Being hygienic
destroying vectors
isolating infected individuals
vaccination
how does the skin work in the defence system?
acts as a barrier to pathogens, scaps over, dead out layer
how does the nose work in the defence system?
hairs and mucus in the nose trap particles that could contain pathogens
how do the eyes work in the defence systenm?
produces tears that are antiseptic and contains enzymes to kill bacteria
how does the breathing system work in the defence system?
trachea and bronchi produce mucus to trap pathogens, they are also lined with cilia that carries the mucus back up in order to be swallowed
how does the stomach work in the defence system?
produces hydrochloric acid, this kills pathogens in food and in swallowed mucus
what is phagocytosis?
when white blood cells engulf pathogens and digest them
how does the structure of white blood cells help with phagocytosis?
they are able to change shape
what are antigens?
an unique molecule on the surface of an invading pathogen
how do white blood cells fight against antigens?
they rapidly produce antibodies that lock onto specific antigens and destroy them
why do white blood cells produce anti toxins?
they counteract toxins that are produced by bacteria
what does a vaccination involve?
introducing small quantities of dead or inactive forms of a pathogen into the body to stimulate the white blood cells to produce antibodies.
why are vaccinations helpful?
if the same pathogen re-enters the body the white blood cells respond quickly to produce the correct antibodies, preventing infection
what cells are produced to help with the vaccination process?
memory cells help with a more rapid response for when a pathogen re enters the body
name an antibiotic
penicillin, this is made out of a penicillium mould, this was discovered by Alexander Fleming
what are antibodies?
Antibiotics, such as penicillin, are medicines that help to cure bacterial disease by killing infective bacteria inside the body.
what is important about the use of antibiotics?
It is important that specific bacteria should be treated by specific antibiotics.
what is good about the use of antibiotics?
The use of antibiotics has greatly reduced deaths from infectious bacterial diseases.
How are viral pathogens treated.
Antibiotics cannot kill viral pathogens.
Painkillers and other medicines are used to treat the symptoms of disease but do not kill pathogens.
Why is it difficult to develop drugs that kill viruses?
Most drugs damage the body’s tissues when attempting to kill the virus
Where are drugs traditionally extracted from?
Plants and microorganisms
Where does the heart drug digitalis originate from?
Foxgloves
Where does the painkiller aspirin originate from?
Willow
What are new drugs tested for?
Toxicity, efficacy and dose
What is the first step of creating a new drug?
Preclinical testing in laboratories using cells, tissue and animals
Who do clinical trails use to test the drug?
Healthy volunteers and patients
How do clinical trails work?
Very low doses of the drug are given at the start of the clinical trial.
If the drug is found to be safe, further clinical trials are carried out to find the optimum dose for the drug.
What is double blind trail?
Where neither the patient or the doctor know who is receiving the real drug or the placebo
When can testing and trails be published?
After scrutiny by peer review
What are monoclonal antibodies produced from?
From a single clone of cells
How do monoclonal antibodies work?
The antibodies are specific to one binding site on one protein antigen and so are able to target a specific chemical or specific cells in the body
How are monoclonal antibodies produced?
They are produced by stimulating mouse lymphocytes to make a particular antibody. The lymphocytes are combined with a particular kind of tumour cell to make a cell called a hybridoma cell. The hybridoma cell can both divide and make the antibody. Single hybridoma cells are cloned to produce many identical cells that all produce the same antibody. A large amount of the antibody can be collected and purified.
What are some uses of monoclonal antibodies?
Diagnosis: pregnancy test
In Laboratories
To treat diseases: cancer
Why are monoclonal antibodies used in labs?
To measure the levels of hormones and other chemicals in blood, or to detect pathogens.
How can monoclonal antibodies help to treat cancer?
the monoclonal antibody can be bound to a radioactive substance, a toxic drug or a chemical which stops cells growing and dividing. It delivers the substance to the cancer cells without harming other cells in the body.
What are the advantages of monoclonal antibodies?
Specific to a particular antigens
Very accurate
Quick results
Can diagnose and help treat disease
What are the disadvantages of monoclonal antibodies?
Side effects, including fever, low blood pressure and vomiting meaning they aren’t used as much as scientists originally intended
How do you monoclonal antibodies work in pregnancy tests?
The pregnancy tests stick contains monoclonal antibodies that are specific to HCG found in pregnant women’s urine.
How do monoclonal antibodies act in the result of a positive pregnancy test?
HCG in urine binds to the monoclonal antibodies that are attached to blue bead and they diffuse up the dipstick forming a blue line
what are the three types of plant defences?
Physical mechanical and chemical
What are the physical plant defences?
Cellulose in cell walls
bark on trees (layer of dead cells)
a tough waxy cuticle layer on leaves
What are the mechanical plant defences?
Thorns and hairs
leaf responses (those that drop/curl when dropped)
Mimicry to trick animals
What are the chemical plant defences?
Antibacterial chemicals
poison to deter herbivores
What are the symptoms of plant disease?
Stunted growth
spots on leaves
area of decay (rot)
malformed stems
discolouration
presence of pests
How can identification of the symptoms be made?
Use gardening websites
taking infected leaves to a laboratory
using testing kits that contain a monoclonal antibodies
What are the causes of plant disease?
Nutrient deficiencies
insects (aphids)
viral, bacteria or fungal pathogens
What happens when there is a deficiency of magnesium with in plants?
Chlorosis
Why is magnesium needed in plants?
They are needed to made chlorophyll
What happens if there is a nitrate deficiency in plants?
Stunded growth
Why is nitrate needed in plants?
They are needed in protein synthesis
How do aphids cause damage to plants?
The extracts sap from the plant phloem weakening the plant and they are also vectors who can transfer pathogens
How can we reduce the number of aphids?
Chemical pesticides
Biological pest control:ladybirds
How do aphids cause damage to plants?
