GCSE AQA Biology - Topic 3 - INFECTION AND RESPONSE Flashcards
What are pathogens?
Microorganisms that enter the body and cause disease
What type of diseases do pathogens cause?
Communicable (infections) diseases, that can easily spread
What can pathogens affect?
Both plants and animals
What are bacteria?
Very small cells which can reproduce rapidly inside your body
What can bacteria do?
Make you feel ill by producing toxins that damage your cells and tissues
What are viruses?
They are not cells, they’re tiny 1/100th the size of bacterium and they reproduce rapidly inside your body
What do viruses do?
Live inside your cells and replicate themselves using the cells machinery to produce many copies of themselves, this cell will then burst releasing all the new viruses
What about a virus makes you feel ill?
The cell damge
What are protists?
They are mostly single-celled eukaryotes, some are parasites, they are often transferred to the organism through a vector
What is a parasite?
They live in or on other organisms and can cause them damage
What is a vector?
An insect that carries the protist
What can fungi be?
Single-celled or have a body which is made up of hyphae
What are hyphae?
Thread-like structures
What do hyphae do?
Grow and penetrate human skin and the surface of plants, causing diseases
What three ways can pathogens be spread?
Water, Air, Direct Contact
How are pathogens spread through water?
They can be picked up by drinking or bathing in dirty water e.g. cholera
What is cholera?
A bacterial infection that’s spread by drinking water contaminated with diarrhoea of other sufferers
How are pathogens spread by air?
They can be carried in the air and then breathed in, some air born pathogens are carried in the air by droplets produced when you cough or sneeze
What is an example of a pathogen spread by air?
The influenza virus
How are pathogens spread by direct contact?
They can be picked up by touching contaminated surfaces, including the skin e.g. athletes foot
What is athletes foot?
A fungus which makes the skin itch and flake off, it is most commonly spread by touching the same thing as the infected person e.g. shower floors or towels
What are the three viral diseases you need to know about?
Measles, HIV, and Tobacco mosaic virus (TMV)
How is measles spread?
Through droplets of an infected persons cough or sneeze
What do people with measles develop?
A red skin rash and a sign of a fever