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

The symbiotic association between fungi and roots of higher plants is called:

1. Lichen

2. Mycorrhiza

3. Biofertilizer

4. BOD

The organisms which are used to enrich the nutrient quality of the soil are called:

1. Mycorrhiza

2. Biofertilizers

3. Yeast

4. Methanogens

Which of the following serve as biofertilizer in paddy fields?

1. Bacteria

2. Yeast

3. Cyanobacteria (blue-green algae)

4. Fungi

The solids which settle after primary treatment of sewage are called:

1. Primary sludge

2. Activated sludge

3. Flocs

4. Total solids