Biology Infection & Response March 2018 Flashcards
What is a ‘Communicable’ disease?
A disease that can be transmitted from one organism to another.
What does infectious describe in biology?
It describes a pathogen that can easily be transmitted, or an infected person who can pass on the disease.
What are the 4 types of communicable disease in humans?
Viruses, bacteria, fungi and protists.
What are examples of each communicable disease in humans?
Virus - Measles.
Bacteria - Salmonella.
Fungi - Candida.
Protist - Malaria = A communicable disease, caused by
a protist transmitted in mosquitoes,
which attacks red blood cells.
How do pathogens spread?
- Airborne
- Through dirty water
- By direct physical contact
- Through contaminated food
- Passed by another animal
What are the first lines of defence in humans?
- Skin
- Lysozymes in tears and saliva
- Hairs & cilia
- Stomach acid
What is the second line of defence in humans?
- Phagocytes
Phagocytes are a type of white blood cell. They engulf pathogens, as well as dead or dying cells. Antibodies cause the pathogens to clump together. The phagocyte then changes it’s shape to engulf the pathogens in a vacuole. Digestive enzymes are then realised and the pathogens are broken down.
What is the third line of defence?
- Lymphocytes
Lymphocytes are another type or white blood cell. Almost all cells have antigens surrounding them. Lymphocytes can detect foreign antigens on invading pathogens. They produce large numbers of antibodies; this takes several days making the human feel ill. The antibodies are highly specific for the type of pathogen meaning that the shape of the antibody fits perfectly.
What is a vaccine?
A vaccine is a medicine containing an antigen from a pathogen that triggers a low level immune response so that subsequent infection is dealt with more efficiently by the body’s own immune system.
What is an antiseptic? Antibiotic?
Antiseptic - A substance applied to the skin or another
surface to destroy pathogens.
Antibiotic - A group of medicines which kill bacteria
and fungi.
What are lysozymes?
Antibacterial enzymes found in your tears to prevent eye infections.
What are cilia?
Tiny hair-like projections from ciliated cells that waft mucus out of the as exchange system.
What is an antigen? Antitoxin?
Antigen - A protein on the surface of a pathogen that
your antibodies can recognise as foreign.
Antitoxin - A protein produced by your body to
neutralise harmful toxins and pathogens.
What is a monoclonal antibody?
Identical antibodies produced from the fusion of mouse spleen cells and myeloma cells.
What are spleen, hybridoma and myeloma cells?
Spleen - An organ in the immune system, found in the
abdomen of most vertebrates, that produces
and destroys red blood cells.
Myeloma - A malignant tumour of white blood cells in
bone marrow.
Hybridoma - A monoclonal antibody producing cell
formed from the fusion of mouse spleen
cells and myeloma cells.
