Topic 3- Infection And Response Flashcards
What are pathogens?
Microorganisms that enter the body and cause disease
What size are bacteria cells in comparison to body cells?
1/100th
One main difference between bacteria and viruses
Viruses are not cells
Are protists prokaryotes or eukaryotes?
They are single cells eukaryotes
What do fungi that aren’t single celled, have?
A body which is made up of hyphae, which are thread like structure which grow and penetrate on skin or surface causing disease.
3 ways pathogens can be spread?
Water- drinking or bathing in dirty water (cholera: bacterial)
Air- carried by air and breathed in or droplets when cough or sneezing (influenza: virus)
Direct contact- touching contaminated surfaces (athelete’s foot: fungus)
Name three viral diseases
Measles, HIV, Tobacco mosaic virus
How is measles spread
Spread by droplets from infected person cough or sneeze
What is tobacco mosaic virus?
Affects plants, causing parts of leaves to become discoloured.
What does the discolouration in plants with TMV mean?
It means plants can’t carry out photosynthesis, so affects growth
How can HIV be spread?
Sexual contact, exchange of bodily fluid (sharing needles)
How can HIV be controlled?
During the time where the person doesn’t experience any symptoms for several years, it can be controlled with drugs, which stop the replication
What type of drugs control HIV?
Antiretroviral drugs
Name a fungal disease
Rose black spot
Symptoms of rose black spots
Causes purple or black leaves in plants. Leaves turn yellow and drops off, causing photosynthesis and therefore growth to be affected.
How is Rose Black Spot spread?
Can be spread through water and wind
How can RBS be controlled?
Using fungicides and stripping affected leaf.
Name a protist disease.
Malaria
Symptoms of malaria
Causes repeating fevers and can be fatal.
Causes of malaria
Mosquitos, when they feed on infected person, they pick up malaria protist and spreads uninfected
How can malaria be controlled?
Reducing chance of mosquitos breeding
Name two bacterial disease and the bacteria they are caused by.
Diarrhoea- salmonella
Gonorrhoea- N/A
Symptoms and spread of diarrhoea
Symptoms: stomach cramps, vomiting, fever
Spread: contaminated food.
Causes and symptoms of gonorrhoea
Cause: sexual contact
Symptoms: pain when urinating, thick yellow or green discharge
Treatment for gonorrhoea
Antibiotics e.g. Penicillin and using contraception
4 ways to reduce disease spread
- Following good hygiene
- Destroying vectors
- Isolating infected individuals
- Vaccinations
What is nonspecific immunity?
first line of defense against infection or injury
3 examples of non specific immunity
Skin- secretes antimicrobial substances
Hair and mucus in nose- traps particles possibly with pathogens
Hydrochloric acid in stomach- kills pathogens
Two types of white blood cells?
Phagocytes and lymphocytes
What are type of lymphocytes?
B lymphocytes and T lymphocytes
What type of white blood cells are memory and plasma cells from?
B lymphocytes
Difference between memory cells and plasma cells
Memory cells are cells with receptors and plasma cells are the cells once they’ve lost the receptors
3 ways antibodies destroy pathogens
Directly killing them, neutralising them and making pathogens clump together
Describe phagocytosis
Phagocytes move toward pathogens and engulf them and release enzymes to break down pathogens
What do anti toxins do?
They counteract toxins produced by bacteria
How do vaccines work?
They have a small amount of dead or inactive pathogen, and the body recognises this as foreign and this stimulates lymphocytes. Memory cells are stored, so if person infected with same live pathogen and can be destroyed quickly.
An example of vaccines
MMR- for measles, mumps and rubella
2 pros of vaccines
- Helped control communicable that were common e.g. Smallpox doesn’t occur and polio has fallen by 99%.
- Prevention of epidemics
2 cons of vaccines
- Vaccines don’t always work in giving immunity
2. Can sometimes have bad reaction
Difference in painkiller drugs and antibiotics
Painkillers are drugs that relieve pain but they don’t tackle pathogen, they just reduce symptoms, but antibiotics kill/prevent growth of bacteria.
Why can’t antibiotics destroy viruses
Because viruses reproduce using body cells so it is difficult to kill it without killing body cells
How can bacteria become resistant?
Bacteria can mutate which can cause resistance
What would happen if an individual resistant bacteria survives?
It will reproduce and the population will increase and could cause serious infection untreatable by antibiotics.
Example of a resistant.
MRSA which causes serious wound infection is resistant to powerful antibiotics methicillin
A way to slow rate of development of resistant strains
Doctors avoid over prescribing and patients should finish whole course.
How do plants defend themselves?
They produce various chemicals
2 Examples of medical drugs from plants.
Aspirin, painkiller and lower fever, made from chemical in willow
Digitalis, for heart conditions, made from chemical in foxgloves
Example of drug from microorganism
Alexander Fleming noticed a Petri dish also had mound and area was free of bacteria. Found that mould produced substance killing bacteria- Pencillin
