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

Given below are three statements (A-B) each with one or more blanks. Select the option which correctly fills the blanks in the statements Statements:

1. A - Antibiotic, Trichoderma polysporum; B - filtration and sedimentation

2. A - Cyclosporin A, Trichoderma polysporum; B - filtration and sedimentation

3. A - Cyclosporin A, Trichoderma polysporum; B - Centrifugation and sedimentation

4. A - Antibiotic, Trichoderma polysporum; B - Centrifugation and sedimentation