12.1 Animal And Plant Pathogens Flashcards
What are communicable diseases caused by?
Infective organisms known as pathogens
What is a pathogen?
A microorganism that can cause diseases
What is a vector?
An organism that spreads disease/pathogens from one organism to another
What are the different types of pathogens?
Bacteria, viruses, protist, fungi
Are bacteria prokaryotes or eukaryotes?
Prokaryotes
What are the two ways of identifying bacteria?
By their shape, and by their cell walls (see how they react to gram staining)
What colour do gram-positive bacteria look under a microscope?
Purple-blue
What colour do gram-negative bacteria look under a microscope?
Red
What does the type of cell wall of a bacteria determine?
How it will react to different antibiotics
What are viruses?
Non-living infectious agents
What is the basic structure of viruses?
Genetic material surrounded by protein
How do viruses replicate?
They invade living cells, where the genetic material takes over the biochemistry of the host cell to replicate itself
What are bacteriophages?
Viruses that infect/attack bacteria
Are protists eukaryotes or prokaryotes?
Eukaryotes
What are the two key pathogen modes of action?
-Damaging the host tissues directly
-Producing toxins which damage host tissues
How do viruses damage the host tissues directly?
-Take over the cells metabolism
-Viral genetic material gets into teh host cell, and is inserted into the host DNA
-Virus uses the cells to make new viruses, which burst out of the cell, destroying it and spreading to other cells
How do protists damage the host tissues directly?
-Take over cells and break them open
-Digest and use the cell contents
How do fungi damage the host tissues directly?
Digest living cells and destroy them
What are toxins?
Poison that are by-products of normal the functions of an organism
What types of pathogens produce toxins?
Bacteria and fungi
What types of pathogens have cell walls?
Fungi, bacterium
What types of pathogens have membrane-bound organelles?
Fungi, protists
