Senior Secondary (HKDSE) · Biology

Use of microorganisms : Practice Questions

5 multiple-choice questions marked as you go, and 3 written questions with worked solutions. All on Use of microorganisms .

8 questions18 marksFree, no account
Question 1
1 mark

In the industrial production of fruit juice, which group of microorganisms is the primary source of pectinase used to clarify the product and increase juice yield?

Question 2
1 mark

In the process of sewage treatment, which group of microorganisms is responsible for the production of biogas in anaerobic digesters?

Question 3
1 mark

During the production of biogas in an anaerobic digester, the conversion of organic wastes into methane involves a consortium of microorganisms. Which of the following correctly describes the metabolic role of methanogens in this process?

Question 4
1 mark

In the process of sewage treatment, microorganisms are utilized in different stages. Which of the following correctly describes the role of microorganisms in the anaerobic digester during the treatment of sludge?

Question 5
1 mark

During the industrial production of biogas, a consortium of microbes is used. If the temperature of the anaerobic digester drops significantly below the optimal range, why does the production of methane decrease?

Question 6
3 marks

Describe the biological role of decomposer microorganisms in the secondary stage of sewage treatment.

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Question 7
5 marks

In the industrial production of biogas, identify the specific metabolic group of microorganisms involved in the final stage and state the environmental condition required for this process.

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Question 8
5 marks

Pectinase is an industrial enzyme frequently used in the production of fruit juices.
(a) Describe the biological action of pectinase on the plant tissues during juice extraction.
(b) State two advantages of using pectinase in the juice industry compared to purely mechanical extraction.
(c) Many industrial processes now use immobilised enzymes. Explain how immobilising pectinase can improve the efficiency and cost-effectiveness of juice production.

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