Acetic acid is produced by a:

(1) Fungus

(2) Bacterium

(3) Yeast

(4) Virus

Citric acid is produced by:

(1) Acetobacter aceti (a bacterium)

(2) Yeast (a fungus)

(3) Aspergillus niger (a fungus)

(4) Streptococcus (a bacterium)

Which of the following bacteria has a role in removing clots from the blood vessels?

1. Bacillus thuringiensis

2. Clostridium butylicum

3. Streptococcus

4. Lactobacillus

Statins used for lowering blood-cholesterol level are extracted from:

(1) Algae

(2) Bacteria

(3) Virus

(4) Yeast

The bioactive molecule cyclosporin A is used in:

1. Whooping cough

2. Diphtheria

3. Leprosy

4. Organ-transplant patients

Cyclosporin A is produced from:

(1) Trichoderma polysporum (a fungus)

(2) Bacillus (a bacterium)

(3) Aspergillus (a fungus)

(4) All of these

The primary treatment of sewage involves:

1. Digestion

2. Decomposition

3. Sedimentation and filtration

4. None of these

The amount of oxygen required by the microbes in the decomposition of organic matter is called:

1. Chemical oxygen demand

2. Biochemical oxygen demand

3. Total oxygen demand

4. Dissolve oxygen

The mixture of gases released during anaerobic digestion of sludge is called:

(1) Methane

(2) Carbon dioxide

(3) Biogas

(4) Flammable gases

Biogas contains:

(1) CO₂

(2) H₂S

(3) CH₄

(4) All of these