B5 - Communicable diseases Flashcards
What is a pathogen?
A microorganism that causes infectious disease.
Through air, through water, direct contact (e.g. STDs), vectors.
Hand-washing, safer sex practices, vaccination, eradication of vectors.
Viruses, bacteria, protists, fungi.
Bacteria and viruses may reproduce rapidly inside the body.May produce poisons (toxins) that damage tissues
Live and reproduce inside cells, causing cell damage
A virus
Fever and a red skin rash.
Inhalation of droplets from sneezes and coughs.
Measles is a serious illness that can be fatal if complications arise.
A virus
HIV initially causes a flu-like illness.
To stop the virus from replicating.
When the body’s immune system becomes so badly damaged it can no longer deal with other infections or cancers.
Sexual contact or exchange of body fluids such as blood which occurs when drug users share needles.
A virus
A widespread plant pathogen affecting many species of plants including tomatoes.
A distinctive ‘mosaic’ pattern of discolouration on the leaves
Reduces the growth of the plant due to lack of photosynthesis
Bacteria
By the bacteria being ingested in food, or on food prepared in unhygienic conditions.
Fever, abdominal cramps, vomiting and diarrhoea
By the toxins that the bacteria release
In the UK, poultry are vaccinated against Salmonella.
Bacteria
Gonorrhoea is spread by sexual contact.
Treatment with antibiotics or use of a barrier method of contraception e.g. condoms.
Thick yellow or green discharge from the vagina or penis and pain on urination.
Lots of antibiotic resistant strains have now appeared.
Lots of antibiotic resistant strains have now appeared.
Purple or black spots develop on leaves, which often turn yellow and drop early.
It is spread in the environment by water or wind.
It affects the growth of the plant as photosynthesis is affected due to discolouration & destruction of the leaves.
Using fungicides and/or removing and destroying the affected leaves.
A protist
Often a parasite that lives on or inside other organisms
An organism that carries and transfers a protist to other organisms without becoming ill itself
Spread via mosquitos (the vector) transferring the malarial parasite (protist) into other organisms
Recurrent episodes of fever and can be fatal
Anti-malarial drugs.
Eradication of vectors such as mosquitos and/or use of mosquito nets at night to avoid being bitten.
Skin, nose, trachea and bronchi, stomach.
Cells secrete mucus that traps pathogens, and cilia cells have hair like structures that remove trapped pathogens
Hydrochloric acid
If a pathogen enters the body the immune system tries to destroy the pathogen.
Phagocytosis (engulfs the pathogens), antibody production, antitoxin production
Name four ways in which diseases caused by pathogens can be spread.
Through air, through water, direct contact (e.g. STDs), vectors.
Name four ways in which the spread of diseases can be reduced or prevented.
Hand-washing, safer sex practices, vaccination, eradication of vectors.
Name the four classes of pathogens.
Viruses, bacteria, protists, fungi.
Why is there a short delay between infection by a pathogen and feeling ill from the infection?
Bacteria and viruses may reproduce rapidly inside the body.
How do bacteria make us ill?
May produce toxins that damage tissues.
How do viruses make us ill?
Live and reproduce inside cells, causing cell damage.
What type of pathogen is measles?
A virus.
What are the symptoms of the measles?
Fever and a red skin rash.
How are measles spread?
Inhalation of droplets from sneezes and coughs.
Why are children vaccinated against measles?
Measles is a serious illness that can be fatal if complications arise.
What type of pathogen is HIV?
A virus
What are the initial symptoms of HIV infection?
HIV initially causes a flu-like illness.
What is the aim of antiretroviral drugs?
To stop the virus from replicating.
How does HIV lead to aids?
When the body’s immune system becomes so badly damaged it can no longer deal with other infections or cancers.
How is HIV spread?
Sexual contact or exchange of body fluids such as blood which occurs when drug users share needles.
What kind of virus is TMV?
A virus
What is TMV and what type of organism does it affect?
A widespread plant pathogen affecting many species of plants including tomatoes.