Three sterilized petri dishes I, II and III were half filled with sterilized nutrient agar jelly and then treated as shown below. The petri dishes were...

Three sterilized petri dishes I, II and III were half filled with sterilized nutrient agar jelly and then treated as shown below.
The petri dishes were then kept in an oven at 36°C. After 2 days the three petri dishes were flooded with iodine solution.

a) Yellow spots were noted in set up I and II while set up III turned blue black.
i) What was the importance of sterilization in the experiment?
ii) Mention TWO ways by which sterilization could have been achieved.
b) Explain the results obtained in each of the three petri dishes after 2 days.

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a) i) Kill microorganisms;
ii) Flame heating ; use of disinfectant;
b) I - enzyme diastase in germinating seed hydrolysed / digested starch in nutrient agar; forming simple sugars;
II- Salivary amylase converted starch in nutrient agar into maltose;
III-Enzyme maltase is inactivated; by pH / acidic medium ;

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sharon kalunda answered the question on May 24, 2019 at 07:48

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