Mitosis and Cell Duplication Flashcards
(11 cards)
When do cells divide
To replace damaged cells
Results in is two identical original cells
What is mitosis (process) ?
The cell grows and increases the amount of sub-cellular structures (e.g mitochondria)
Duplicates the DNA before lining up at the centre ans spliting
They get pulled to opposite sides of the cell before splitting and forming two daughter cells
What undergoes binary fission?
Prokaryotic cells
How does binary fission occur
The circular DNA and plasmids replicate
The cells increase in size and the circular DNA is pulled to opposite poles
The cells divide and two daughter cells are produced
How are microorganism grown?
Added to nutrient broth or solid agar jelly
How to make an agar plate
Hot agar jelly is poured into petri dishes
Once the jelly has set the inoculating loops are used to transfer microorganisms to a culture medium. Or a sterile pipette is used to transfer microogranisms
How are microorganisms grown in school?
Not above 25’C due to harmful pathogens being able to be grown
How are microorganisms grown in industry
Above 25’C as it has higher duplication rates due to optimum temperstures
What is the investigation to grow microorganisms?
Place paper discs in different types/concentrations of antibiotics on a petri dish with an even covering of bacteria
The antiobiotics will cause the bacteria to die and leave a clear area called the inhibition zone.
There must be a control apper disc with no antibiotic or soaked in sterile water
Leave the plate at 25’C for 48 hour
The larger the inhibition zone means the more effective the antiobiotic is.
How to obtain uncontaminated cultures?
Sterile petri dishes and culture mediums (e.g. high temperatures) to kill unwanted microorganisms
Inculating loop (used to transfer bacteria) must be passed through a hot flame
Petri dish should be taped shut to prevent microorganisms from the air getting in
Petri dish should be stored upside down to prevent condensation falling onto the agar surface
How to measure the inhibition zone
Measure diameter of inhibition zone and then use it to Pi X r2
