Growing Microbes Flashcards
How can colonies of microbes be grown
in a petri dish
The growth medium is…
nutrient agar
What temperature is the dish incubated at and why?
- 25 degrees centigrade
- It encourages growth of microbes
What is the stationary phase when growing microbes?
It’s when things necessary for organisms is in short supply so the birth rate = death rate
what is the lag phase when growing microbes?
It’s when organisms are adjusting their surroundings and are not reproducing much
what is the death phase when growing microbes?
It’s when things needed for life run out or something in the surroundings start to kill the organisms
what is the log phase when growing microbes?
It’s when conditions for reproduction are good and the colonies grow rapidly
Why is the petri dish sealed? (give 2 reasons)
-To prevent contamination of the dish
-To prevent accidental contamination of us by any microbes that have grown on the dish
Why should you not incubate the dish at 37 degrees centigrade?
Because this may encourage growth of pathogens dangerous to our heath
As bacteria reproduce using binary fission, increasing their numbers exponentially during the log phase, what are some ways to slow down or even stop the log phase.
- Take away food
- Take away oxygen
- Extreme heat
- Extreme cold
