Biology Term 2 (DEFINITIONS)
Specificity
Recognition and response to chemicals that coat pathogens.
Memory
A second exposure to the same pathogen produces a larger and more rapid response.
B Cells
A type of white blood cell that produces antibodies.
T Cells
A type of white blood cell that recognises chemicals on the outside of pathogens and kills the pathogenic cell or an infected cell.
Parasite
An organism that feeds on an another organism called the host.
Gram Positive Bacteria
Cell wall made of a thick later of peptidoglycan, turns purple when stained,
Gram Negative Bacteria
Cell wall made of a thin later of peptidoglycan and a thick later of polysaccharides.
Zone of Inhibition
Clear zones around each disc show zones where bacteria have died.
Parasites
A parasite is an organism that feeds on another organism, called the host.
Immune System
3-tiered system that prevents and kills disease-causing pathogens.
Infectious Disease
A condition caused by a disease-causing agent (organism or virus).
Disease
A condition that impairs the normal activity of an organism.
Non-infectious Disease
A disease that may be genetically inherited or caused by exposure to dangerous chemicals/conditions.
Lymphocyte
A form of a small white blood cell occuring most commonly in the lymphatic system.
Macrophage
A large white blood cell that is an important part of the immune system.
Antigen
Foreign cell or pathogen.
Carriers
Organisms can be infected by a disease-causing bacterium without showing symptoms.
Endo-parasites
Parasites that live inside your body
Ecto-parasites
Parasites that live outside your body
Endotoxins
Part of the cell wall of gram-negative bacteria, composed mostly of lipids.
Exotoxins
Part of the cell wall of gram-positive bactera, released as part of a normal bacteria growth.
Antibodies
Produced in response to and counteracting a certain antigen.
Bacteria
Prokaryotic cells of the monera kingdom
Symptoms
Symptoms are the physical changed or impairments that occur when the host is infected by the pathogen.
Virulence
The amount of harm done to the host by the pathogen.
Pathogen
The disease causing organism.
Host
The organism that gets the disease.
The Life Cycle of a Parasite
The process of parasites growing from a juvenile stage to an adult stage.
Vectors
The secondary hosts that are responsible for the transmitting the disease to the primary host.
Natural Reservoir
The source of infection.
Transmission
When someone is infected with a pathogen, this is called the transmission of a disease.
Primary Host
Where the adult stage of the parasite lives.
Secondary Host
Where the juvenille stage of the parasite lives.
Phagocyte
White blood cells