B3 Flashcards
what are the different ways pathogens can be spread
Water
Air
Direct contact
How can pathogens be spread by water
You can pick up the pathogens by consuming or bathing in dirty water
You can spread the pathogens by drinking contaminated water
How can pathogens be spread by air
Pathogens can be carried by the air in droplets when you cough and sneeze and they can be breathed in
How can pathogens be spread by direct contact
Can be picked up and spread by touching contaminated surfaces (including skin)
Examples of viral diseases
Measles
HIV
what is measles
what: a viral disease spread by droplets of an infected persons cough or sneeze
issues: if there are complications, can be serious
symptoms: red skin rash, fever
treat: vaccinations against virus usually done at youth
What is HIV
what: virus spread by sexual contact or by exchanging bodily fluids
issues: attacks immune cells, if badly damaged then body can’t fight other infections (aids/late stage)
symptoms: initial symptoms are flu like
treat: can be controlled with antiretroviral drugs to stop virus from replicating
Examples of bacterial diseases
Salmonella
Gonorrhoea
What is salmonella
what: type of bacteria causing food poisoning
issues: food poisoning if contaminated food is consumed
symptoms: fever, stomach cramps, vomiting, diarrhoea
treat: most poultry is given vaccinations to control spread of disease
what is gonorrhoea
what: sexually transmitted disease
Issue: originally treated with penicillin but it’s more difficult due to antibiotic restraint
symptoms: pain while urinating, thick yellow or green discharge
treat: use condoms to prevent spread, use antibiotics to treat
give an example of a protist disease
Malaria
What is malaria
what: disease of which mosquitoes are the vector by feeding on infected animals and passing on
issue: can be fatal
symptoms: repeating fevers
treat: stopping mosquitoes breeding to prevent spread,use insecticides and mosquito repellent
how is the skin a defence system
- forms a protective, outer layer of skin on the body which consists of dead cells and is difficult for pathogens to penetrate through
- secretes antimicrobial substances as well as sebum which can kill bacteria
- scabs form over wounds to prevent pathogens from entering the body
how does the stomach act as a defence system
- contains hydrochloric acid which kills pathogens before they can make it further down into the digestive system
How is the nose a defence system
- contains hairs and mucus which trap particles that could contain pathogens
- this prevents the pathogens from entering the breathing system
How is the trachea and bronchi a defence system
- secrete mucus to trap pathogens
- contain cilia which waft the mucus up to the back of the throat where it can be swallowed
How does the immune system act as a defence system
- destroys pathogens and any toxins the produce
- protects us in case the same type of pathogen invaded us again in future
explain phagocytosis
- once the phagocyte (wbc) detects a foreign cell, it engulfs the pathogen
- it then uses enzymes to digest and destroy the cell
Explain the line of attack when antibodies are produced
- Once in contact with forge in cells, Lymphocytes (wbc) produce y-shaped proteins called antibodies which bind to invading cells so that they can be destroyed
- the antibodies are specific and will only bind to its specific antigen
- they are rapidly produced once made and are carried around the body
What are memory lymphocytes
- produce the same antibodies of an infection we have previously had in case we catch it again.
- the antibodies will be produced rapidly and so the person will naturally become immune to the pathogen
Explain the line of attack whe antitoxins are produced
- white blood cells produce antitoxins which stick te toxins molecules produced by invading cells and prevent them from damaging cells
What is the tobacco mosaic virus
what - virus that affects many species of plants
issue - discolouration means plants can’t carry out photosynthesis as well and leads to stunt growth
symptoms - causes mosaic pattern on leaves and discolouration
What is rose black spot disease
what - fungal disease that affects plants
issue - causes rate of photosynthesis to fall which then reduces rate of growth
Symptoms - development of black or purple spots on leaves
treat - spray plant with chemicals which can kill fungi or/and remove infected leaves and destroy them.
what is the process of vaccination
- inactive forms of a pathogen which carry antigens are injected into your body causing it to produce antibodies to attack them
- the wbc undergoes mitosis and multiplies to produce more antibodies
- if a live pathogens of the same type enter the body, wbcs can rapidly produce the antibodies needed to kill the pathogen which prevents infection
what are the pros of vaccinations
- Helps control many communicable diseases
- Epidemics can be prevented if a large percent of population is vaccinated
What is herd community
where that is most people are vaccinated, the unvaccinated are unlikely to catch the disease as there are fewer people to catch it from
What are the cons of vaccination
- Don’t always work
- Bad reactions to vaccines can happen
What was the first antibiotic discovered
Penicillin
what are antibiotics
drug that kills infective bacteria inside the body without harming cells