2022 diversity

Question 1

what are steps that should be followed to ensure that conditions are aseptic

Answer 1

-sterile flask/ pippette/ broth
-stopper flask to prevent contamination
-disinfect/sterilise
-bunsen burner flame

Question 2

why is it important that aseptic techniques are present

Answer 2

-prevent contamination of unwanted microorganisms
-prevent entry/ growth of unwanted microorganisms

Question 3

why is a logarithmic scale used

Answer 3

differences in numbers would be too big to represent on paper

Question 4

in a fermenter, describe what happens during the decline phase

Answer 4

reproduction rate lower than death rate
total count/ dead bacteria much higher than viable bacteria
increased level of waste products
less oxygen and fewer named nutrients
increased intraspecific competition
dead cells/ lack of space

Question 5

how can a graph show that environmental factors cause variation

Answer 5

bell shaped/ normal distribution
data is continuous

Question 6

advantages of using microorganisms in food production

Answer 6

no welfare/ ethical issues
can be genetically modified relatively easily
rapid growth
production can be changed to meet demand
non seasonal/ year round
take up little space

Question 7

why is a cooling system necessary in a fermenter

Answer 7

temp affects rate of growth/ enzyme activity
fungal metabolic reactions generate heat
inhibit growth of pathogenic bacteria