Free Man and His Environment MCQs with Answers

• A. Yeast - statins
• B. Acetobacter aceti - acetic acid
• C. Clostridium butylicum - lactic acid
• D. Aspergillus niger - citric acid

Explanation: Microbes are used for commercial and industrial production of certain chemicals like organic acids, alcohols, and enzymes.

• A. Biogas is produced by the activity of aerobic bacteria on animal waste
• B. Methanobacterium is an aerobic bacterium found in the rumen of cattle
• C. Biogas, commonly called gobar gas, is pure methane
• D. Activated sludge­-sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria.

Explanation: Sewage water can be purified by passing it through sewage treatment plants with the action of heterotrophic microorganisms.

• A. Baculovirus
• B. Bacillus thuringiensis
• C. Glomus
• D. Trichoderma.

Explanation: The natural method of pest and pathogen control involving the use of viruses, bacteria, and other insects (which are their natural…

• A. Rhizobium
• B. Azospirillum
• C. Oscillatoria
• D. Frankia

Explanation: Azospirillum is an anaerobic nitrogen-fixing bacteria that forms loose associations with the roots of some plants.

• A. Glomus
• B. Earthworm
• C. Oscillatoria
• D. Snail

Explanation: Organic farming is a method of farming that primarily aims to keep the soil alive and in good health by the use of organic wastes and…

• A. Alcohol ­- Nitrogenase
• B. Fruit juice ­- Pectinase
• C. Textile -­ Amylase
• D. Detergents ­- Lipase

Explanation: Yeast species are used in alcoholic fermentation due to the presence of the zymase enzyme.

• A. Trichoderma harzianum
• B. Nucleopolyhedrovirus (NPV)
• C. Xanthomonas campestris
• D. Bacillus thuringiensis

Explanation: The natural method of pest and pathogen control involving the use of viruses, bacteria, and other insects (which are their natural…

• A. Gene transfer in higher plants
• B. Biological control of soil­-borne plant pathogens
• C. Bioremediation of contaminated soils
• D. Reclamation of wastelands.

Explanation: The natural method of pest and pathogen control involving the use of viruses, bacteria, and other insects (which are their natural…

• A. Frankia
• B. Azorhizobium
• C. Bradyrhizobium
• D. Clostridium

Explanation: The most common symbiotic association of legumes and bacteria on roots is as nodules, which are small outgrowths on the roots.

• A. Gliocladium virens
• B. Paecilomyces lilacinus
• C. Pisolithus tinctorius
• D. Pseudomonas cepacia

Explanation: Paecilomyces lilacinus proved effective for the biological control of nematode diseases in plants.

• A. Cancer-inducing microbes
• B. New kind of food allergens
• C. Live microbial food supplement
• D. Safe antibiotics.

Explanation: Probiotics are dietary supplements containing potentially beneficial bacteria or yeast, with lactic acid bacteria (LAB) as the most common…

• A. Cyanobacterial symbiosis with some aquatic ferns
• B. Gall formation on certain angiosperms by Agrobacterium
• C. Nodulation of Sesbania stems by nitrogen-fixing bacteria
• D. Plant growth stimulation by phosphate­ solubilizing bacteria.

Explanation: Agrobacterium tumefaciens is the causative agent of crown gall, an important disease of many commercial crops.

• A. Ammonia
• B. Methane
• C. Ethane
• D. Butane

Explanation: Biogas or gobar gas is a methane-rich fuel gas produced by anaerobic breakdown or digestion of biomass with the help of methanogenic…

• A. Lipids
• B. Lignin
• C. Hemi­-cellulose
• D. Cellulose

Explanation: Lignin is a complex polymer of phenylpropane units, which are cross-linked to each other with a variety of different chemical bonds.

• A. Methanogens
• B. Nitrifying bacteria
• C. Ammonifying bacteria
• D. Denitrifying bacteria

Explanation: Methanogens are any of various archaebacteria that produce methane; they include genera such as Methanobacillus and Methanothrix.

• A. Yeast
• B. Bacteria
• C. Virus
• D. Protozoans

Explanation: Saccharomyces converts starch or sugars to pyruvic acid through the EMP pathway.

• A. Oleic acid
• B. Linolenic acid
• C. Linoleic acid
• D. Erucic acid

Explanation: Erucic acid is an unsaturated fatty acid belonging to the oleic acid series, occurring as glycerides in rapeseed oil and other vegetable…

• A. Azolla
• B. Salvinia
• C. Marsilea
• D. Isoetes

Explanation: Azolla plays a very important role in rice production. Azolla and its nitrogen-fixing partner, Anabaena, have been used as green manure to…

• A. Penicillin
• B. Saccharomyces
• C. Azotobactor
• D. Lactobacillus

Explanation: Saccharomyces converts starch or sugars to pyruvic acid through the EMP pathway.

• A. Marsilia
• B. Pteridium
• C. Azolla
• D. Salvinia

Explanation: Azolla plays a very important role in rice production. Azolla and its nitrogen-­fixing partner, Anabaena, have been used as green manure…