Infection and Response Flashcards
What are the four types of pathogen?
- Viruses
- Bacteria
- Protists
- Fungi
What is the difference between a communicable and a non-communicable disease?
A communicable disease is infectious disease while a non-communicable disease is not
What is the definition for a pathogen?
A microorganism which can cause an infectious disease
How do bacteria make us feel ill?
They produce toxins which damage tissue
How do viruses make us feel ill?
They reproduce inside cells causing cell damage
Name 3 example of viral diseases
- Measles
- HIV
- Tobacco mosaic virus (TMV)
What are the symptoms of measles ?
- Symptoms of fever
- Red skin rash
How severe is measles?
Measles is a serious illness which can be fatal
Is there a cure or a vaccine to measles?
There is no known cure however a MMR vaccine is used to young children
How is measles spread?
By air by inhaling droplets from sneezes or coughs
What are the symptoms of HIV?
Flu-likesymptoms
What can HIV lead to?
If not treated with antiretroviral drugs HIV can develop into AIDS and attack the immune system
Is there a cure or a vaccine to HIV?
Neither, however antiretroviral drugs can be given to combat the virus
How is HIV spread?
By sexual contact or exchange of bodily fluids
What are the symptoms of TMV?
- Mosaic pattern discoloration on a plant’s leaf
- Smaller plant
What can TMV lead to?
Stunted plant growth
Name 2 examples of bacterial diseases
- Salmonella
- Gonorrhoea
What are the symptoms of Salmonella?
- Fever
- Abdominal cramps
- vomiting
- diarrhoea
How can salmonella be treated and is there a vaccine?
Directly treated with antibiotics; poultry vaccination to control the spread of the disease
How is salmonella spread?
Ingesting ill-prepared or unhygienically produced food ingesting the bacteria
What are the symptoms of Gonorrhoea?
- Yellow or green discharge from sex organs
- Pain when urinating
How can Gonorrhoea be treated?
Directly treated with antibiotics (penicillin) or protection via use of contraception
How is Gonorrhoea spread?
Spread by sexual contact
Name a fungal disease
-Rose black spot
What are the symptoms of Rose black spot?
- Purple or black spots develop on the leaves
- Yellowing leaves dropping early
- Stunted growth
How can Rose black spot be treated?
Directly treated with fungicides and prevented by removing infected plants
How is Rose black spot spread?
Spread via spores in the wind or water
Name a protist disease
Malaria
What is the vector for malaria?
Female mosquitoes
What are the symptoms of malaria?
Recurrent fever
What can malaria lead to?
Death
How can malaria be treated?
Lariam- a drug which kills the protist
How can malaria be prevented?
Stopping the vector from biting humans; mosquito nets can be used
How does the skin protect the body?
Physical barrier to prevent damage as well as oils secreted to kill microbes
How does the nose protect the body?
Nasal hair keep out dust and larger microorganisms while mucus traps dust and microbes
How does the stomach protect the body?
Highly acidic stomach acid destroys microorganisms which enter the gut
How do the trachea and bronchi protect the body?
Mucus traps dust and microbes before being carried away by cilia, tiny hairs, which line the walls of the trachea and bronchi
Name the two types of white blood cell
- Phagocytes
- Lymphocytes
What is the role of phagocytes?
- To ingest and absorb pathogens or toxins
- Release enzymes to destroy pathogens or toxins
What is the role of lymphocytes?
- Bind to and destroy pathogens
- Clump pathogens together
- Produce antibodies and antitoxins
How do antibodies work?
It is a protein with a chemical fit to an antigen to neutralise the pathogen
How do antitoxins work?
They stick to a toxin and stop it from damaging the body
How do vaccines work?
By stimulating white blood cells to produce the correct antibodies for an inactive form of the illness. Thus, the immune response will be much greater when a hostile form of the disease enters the body.
Name an antibiotic
Penicillin
How do antibiotics work?
They kill infective bacteria within the body; specific antibiotics are more effective versus different bacteria
What is the problem with using antibiotics?
Bacteria develop a resistance to strains of antibiotics making them ineffective
Why is it difficult to produce a drug to combat a virus?
Most drugs that would kill the virus would also combat and damage tissue within the body
What do painkiller not do?
Kill pathogens
Where does the heart drug digitalis originate from?
Foxgloves
Plant
Where does aspirin originate from?
Willow
Where does penicillin come from?
Penicillium mould
Where is the starting point for all drugs?
Chemical extraction from a substance (usually a pant)
What are drugs tested for?
- Toxicity
- Efficacy (desired result)
- Dose
Why are preclinical trials used?
By testing on cells, tissues and live animals before humans pharmaceutical companies can reduce the risk to human life
What occurs in clinical trials?
- Low dosage tests for efficacy
- Dosage test to find optimum
- double blind trials to ensure the effect is not a placebo
In terms of ions stunted growth in plants is as a result of what?
Nitrate deficiency in the soil
In terms of ions chlorosis in plants is as a result of what?
Magnesium deficiency in the soil
What are the physical defences of a plant?
- Cellulose cell walls
- Waxy cuticles on leaves
- Dead cells around a stem (bark)
What are the chemical defences of a plant?
- Antibacterial chemicals
- Poisons
What are mechanical defences of a plant?
- Thorns and hairs
- Leaves which droop or curl
- Mimicry
