Infection and response Flashcards
What are the different types of pathogens?
Bacteria, viruses, protists and fungi
What are bacteria?
Very small cells, can reproduce rapidly in body and produce toxins that can damage cells
What are viruses?
Not cells, reproduce rapidly, replicate themselves using cells information and burst cells making you feel ill.
What are protists?
Single celled eukaryotes and are often parasites that live on or inside other organisns
What are fungi?
Either single-celled, or have a body made up of hyphae which can grow, penetrate plants and produce spores
How can pathogens spread?
Water, air or direct contact
What are the symptoms of measles and how is it spread?
Red skin rash and droplet infection
What are the symptoms of HIV and how is it spread?
Flu-like symptoms, then no symptoms for a few years and by sexual contact or exchange of bodily fluids
How does HIV damage the body?
The virus attacks the body’s immune cells so it can’t defend itself from other infections
What are the symptoms and affects of TMV?
Causes a mosaic pattern on the leaves so plants can’t carry out photosynthesis so it affects the plant’s growth
What are the symptoms and affects of rose black spot?
Purple/black spots, leaves turn yellow then drop off and less photosynthesis so plant’s growth is stunted
What are the causes and symptoms of malaria?
Infection from mosquito inserting protist into blood cells and causes repeating episodes of fever
How do you get salmonella food poisoning and what does it cause?
Eating contaminated food and it causes fever, stomach cramps, vomiting and diarrhoea
How is gonorrhoea spread and what are the symptoms?
Sexual contact and causing pain when urinating and a yellow or green discharge
How can the spread of disease be prevented?
Being hygienic, destroying vectors, isolating infected individuals and vaccination
What features does the human body have to prevent pathogens from entering?
Skin as a barrier with antimicrobial substances, hair with mucus in nose to trap particles, trachea with mucus as well, cilia in throat waft back up substances and hydrochloric acid in the stomach
What is phagocytosis?
Where white blood cells engulf foreign cells and digest them
How do white blood cells produce antibodies to stop pathogens?
The antibodies produced are specific to a type of antigen, once they lock onto the shape, antibodies are then produced rapidly to fight off the infection. If the pathogen comes back, then the body remembers
How do antitoxins stop pathogens?
These counteract toxins produced by invading bacteria
What is a vaccine?
Injecting someone with a small amount of dead or inactive bacteria so that your body can produce antibodies to attack them and remember this if the pathogen ever comes back
What are the pros of vaccination?
They can control communicable problems and prevent epidemics
What are the cons of vaccination?
They don’t always work and you can sometimes have a bad reaction to them
How do painkillers work?
They relieve pain by reducing the symptoms, but not by taking care of the actual disease
How do antibiotics work?
They kill or prevent the growth of the bacteria causing the problem, but do not destroy viruses
How can bacteria become resistant to antibiotics?
They can mutate - some of the mutations may be resistant and when the bacteria is treated, only the non-resistant strains will be killed
Where is aspirin from?
It was developed from a chemical found in the willow
Where was penicillin from?
A type of mould
What are the three main stages in drug testing?
Preclinical testing on human cells and tissues, preclinical testing on live animals and testing on human volunteers (healthy ones, then ones with the disease, then placebos)
What are monoclonal antibodies?
Identical antibodies
How are monoclonal antibodies produced?
By fusing a B-lymphocyte (type of white blood cell) to a tumour cell to create a hybridoma which can be cloned to get lots of identical cells which all produce the same type of antibodies
How do pregnancy tests work if you’re pregnant?
The part of the stick you wee on has some antibodies to the pregnancy hormone with blue beads attached to them and the test strip has some of these as well. If you’re pregnant then the hormone binds to the antibodies on the blue beads, which then moves up the strip and the same thing happens on the strip so the strip turns blue
How do pregnancy tests work if you’re not pregnant?
The urine stills moves up the stick, carrying the blue beads but there’s nothing to stick it onto the test strip so it doesn’t go blue
How can monoclonal antibodies be used to treat cancer?
You can make monoclonal antibodies that bind to the tumour markers (antigens) then attach an anti-cancer drug to this so the drug kills the cancer cells but not the healthy ones
What are the problems with monoclonal antibodies?
They have side effects such as fever, vomiting and low pressure which means that they are not as widely used as was originally thought
What are the common signs of disease in plants?
Stunted growth, abnormal growths, spots on the leaves, malformed stems or leaves, patches of decay and discolouration
What physical defenses do plants have?
Waxy cuticle as barrier, cell walls as physical barrier and layers of dead cells around stems as another barrier
What chemical defences do plants have?
Some can produce antibacterial chemicals and others can produce poisons which can deter herbivores
What mechanical defences do plants have?
Thorns/hairs, some droop or curl when touched and some mimic other organisms to trick organisms into not eating them
