Bacteria and Viruses Flashcards
What is the definition of bacteria?
- bacteria are small, single-celled prokaryotes
What are plasmids?
- small, circular loops of DNA (molecule) in bacteria/ prokaryotes
What are viruses?
- viruses are non-cellular infectious particles
What are membrane-bound organelles?
- membrane-bound organelles are organelles that are surrounded by a phospholipid bilayer
What does binary fission refer to?
In what type of cells does binary fission typically occur in?
- binary fission is a form of asexual reproduction in which a parent cell divides to form two identical daughter cells
- binary fission typically occurs in prokaryotes and a few single-celled eukaryotes
What are mesosomes?
What are the pili? (pilus singular)
What is the flagellum?
What does host refer to?
What does the lysis refer to?
What are antigens?
What is a pathogen?
What are five examples of bacteria?
- TB (Tuberculosis)
- E.Coli
- Salmonella
- Cholera
- Lyme disease
What are five examples of viruses?
- COVID
- HIV/ AIDS
- Tobacco mosaic
- measles
- common cold
What are three examples of fungi?
- athletes foot
- ringworm
- black sigatoka
What are three examples of protoctists?
- tate worm
- malaria
- late tomato blight
What are the similarities of bacteria and viruses?
- no nucleus
- no membrane-bound organelles
- can cause disease
What type of cells are bacteria? What size are they? How do they reproduce?
- bacteria are prokaryotic cells
- They have an average diameter of 0.5-5 micrometre (um)
- they reproduce by binary fission
Where is the genetic material of bacteria found? Does bacteria have ribosomes?
- genetic material found as circular DNA
- may have DNA plasmids
- Bacteria has (smaller than eukaryotes) 70s ribosomes
How do bacteria move? What does bacteria have that allows it to attach to neighbouring cells?
- bacteria may have a flagellum for movement
- has protein tubes called pili (singular pilus) allowing it to attach to neighbouring cells
Can bacteria be killed? Are bacteria living or non living cells?
- bacteria can be killed by antibiotics
- bacteria are living cells
Do eukaryotes have a flagellum?
- not all but some do e.g. sperm - although it has a different structure to prokaryotes flagellum
What are the organelles in bacteria? What are their functions?
- cell surface membrane
- (polysaccharide) cell wall
- capsule = prevents desiccation
- flagellum
- mesosome
- main circular DNA
- plasmids
- pili (pilus)
- ribosomes
What are the two parts to a virus?
- protein coat
- nucleic acid
What is the name of the cell a virus infects? What is cell lysis and when does it happen in viral reproduction?
- the name of the cell a virus infects is a host cell
- lysis is when host cell splits open releasing new viral particles
What is an ‘enveloped virus’? Where is this envelope taken from? What does the envelope carry?
- some viruses have an outer envelope taken from the host cell’s cell surface membrane
- the envelope carries viral antigens, glycoproteins which help the virus attach to the host cell and penetrate the cell surface membrane
- as they are ‘foreign’, antigens can be recognised by host’s immune system
Are viruses living or non-living?
What is the general structure of a virus, prokaryote, eukaryote?
-
Is the DNA looped or linear in a virus, in a prokaryote and in a eukaryote?
What is the main genetic material?
