Animal And Plant Pathogens Flashcards
1
Q
What is a communicable disease
A
A disease that can be passed from one organism to another
2
Q
What are the 4 types of pathogen
A
- bacteria
- virus
- protoctista (Protista)
- fungi
3
Q
Describe the structure of bacteria
A
- prokaryotes
- no nucleus (contains plasmids)
- saprophytic
- 1-1.5 micro metres
4
Q
What is he structure of viruses
A
- no nucleus (does contain DNA/RNA
- no organelles
- very small and simple ( 0.3 micrometers)
5
Q
What are the 2 ways Bacteria can be classified
A
- by their shape, rod shape, comma shaped, corkscrew etc.
-by their cell walls, 2 main types of cell wall have different structure and react differently to gram staining.
GRAM POSITIVE bacteria look PURPLE/BLUE under light microscope eg. MRSA
GRAM NEGATIVE bacteria appear red under the light microscope eg gut bacteria (E.coli) - different cell walls react to different antibiotics
6
Q
What is the structure of protoctista
A
- eukaryotes
- can be single cells or groups of cells
- parasitic
- has a nucleus
7
Q
What is the structure of fungi
A
- eukaryotes
- saprophytic or can be parasitic
- ## have a nucleus
8
Q
What is the mode of action of pathogenic bacteria
A
- they produce toxins that poison or damage the host cell, causing disease
- some toxins damage cell membrane
- some toxins damage or inactivate enzymes
- some toxins interfere with genetic material so host cell cannot divide
9
Q
What is the virus mode if action
A
- viruses take over the cell metabolism , the viral genetic material gets into the host cell and is inserted into the host DNA
- the virus uses the cell to make more virus and eventually burst out destroying the cell and letting more virus spread
10
Q
What is the Protista mode of action
A
- protoctista break open cells and use the cell contents to reproduce
11
Q
What is the fungi mode of action
A
- some fungi digest living cells and destroy them
- some fungi produce toxins which affect the host cell
