B10 - Diseases and Immunity Flashcards
What is a disease? [2]
the state of the body when it cannot cope with changes by the normal homeostatic methods
What is a pathogen? [1]
a disease causing organism
What is a transmissible disease? [2]
a disease in which the pathogen can be passed from one host to another
What are examples of non-transmissible diseases? [3]
- red-green colour blindness = genetics
- heart disease = diet
- cystic fibrosis = genetics
Name the features of a bacteria cell. [8]
- cell wall
- cell membrane
- ribosomes
- cytoplasm
- nucleoid
- plasmid
- pili
- capsule
What is a nucleoid? [2]
- DNA
- circular chromosome
What is pili? [1]
helps stick to the cells
What is the cell wall in a bacteria cell made of? [1]
peptodoglycan
What do viruses include? [3]
- protein coat
- DNA/RNA
- envelope
What are 4 facts about viruses? [4]
- they are particles rather than cells
- they don’t have a cellular structure
- they only reproduce inside other living cells
- they are both pathogens and parasites
How do transmissible diseases spread? [2]
- through direct contact
- through indirect contact
How is a pathogen transmitted by direct contact? [1]
through blood and other body fluids
How is a pathogen transmitted indirectly? [4]
- from contaminated surfaces
- food
- animals
- air
How does a clean water supply prevent transmission of pathogens? What’s the process? [3]
- filter the water
- add chlorine
- kills pathogens
How does hygienic food preparation prevent transmission of pathogens? What’s the process? [3]
- preparing food in hygienic conditions
- reduces the spread of pathogens from work surfaces and chopping boards to food
- kills pathogens
How does good personal hygiene prevent transmission of pathogens? What’s the process? [2]
- washing your hands after going to the toilet
- prevents the spread of disease
How does waste disposal prevent transmission of pathogens? What’s the process? [3]
- not letting rubbish build up
- having systems in place to safely dispose of things like soiled bandages and used needles
- prevents the spread of disease
How does sewage treatment prevent transmission of pathogens? What’s the process? [3]
- having a good system for sewage treatment
- prevents sewage from contaminating drinking water
- reduces the spread of water-borne pathogens
What are the different body defences against pathogens? [4]
- skin
- hairs in the nose
- stomach acid
- mucus
What type of barrier is the skin and how does it work? [2]
- mechanical barrier
- if damaged, blood clots are formed by platelets to quickly seal cuts and prevent the entry of pathogens
What type of barrier are the hairs in the nose and how do they work? [2]
- mechanical barrier
- traps particles from the air that could contain pathogens
What type of barrier is stomach acid and how does it work? [3]
- chemical barrier
- stomach produces acid which kills pathogens
- gets rid of stuff in food and water
What type of barrier is mucus and how does it work? [3]
- chemical barrier
- cells lining the trachea secrete mucus which traps pathogens in incoming air
- ciliated cells waft the mucus back up to the throat to be swallowed
What are the features of viruses? [2]
- protein coat
- genetic material
