Free Man and His Environment MCQs with Answers

• A. Reduction
• B. Recycling
• C. Afforestation
• D. Deforestation

Explanation: The correct answer is Afforestation. This term refers to the process of creating a forest, especially on land that was not previously…

• A. Toxic gases
• B. Heavy metals
• C. Plastic garbage
• D. Inorganic nutrients

Explanation: Eutrophication is the process by which a body of water becomes overly enriched with minerals and nutrients, leading to excessive growth of…

• A. Mechanical processes
• B. Biological processes
• C. Physical processes
• D. Chemical processes

Explanation: This is usually done with the help of microorganisms(bacteria), hence it is called biological treatment.

• A. primary
• B. secondary
• C. tertiary
• D. Quaternary

Explanation: The stage of sewage treatment described is called "primary sedimentation." It involves holding the sewage in a quiescent basin, allowing…

• A. Sulfur dioxide is an essential nutrient for lichen growth
• B. Lichens are good pollution indicators
• C. Lichens use sulfur dioxide in photosynthesis
• D. Sulfur dioxide has relation with lichen growth

Explanation: Sulfur dioxide (SO2) can actually have a significant impact on lichen growth and health.

• A. O radical
• B. H radical
• C. OH radical
• D. H3O radical

Explanation: The complex reactions of ozone with water in the troposphere that are driven by sunlight produce OH radical, which is a highly reactive…

• A. Carbon dioxide
• B. Sulfur dioxide
• C. Carbon monoxide
• D. Ammonia

Explanation: Carbon dioxide is not considered a primary pollutant of the troposphere because it is a natural component of the atmosphere and is…

• A. Yeast ­- Ethanol
• B. Streptomycetes ­- Antibiotic
• C. Coliforms ­- Vinegar
• D. Methanogens ­- Gobar gas

Explanation: Coliform bacteria are a commonly used bacterial indicator of the sanitary quality of foods and water.

• A. Streptomyces- Antibiotic
• B. Serratia-Drug addiction
• C. Spirulina Single-celll protein
• D. Rhizobium­-Biofertilizer

Explanation: Serratia marcescens is considered a harmful human pathogen that has been known to cause urinary tract infections, wound infections, and…

• A. The method is less effective as compared with the use of insecticides.
• B. The practical difficulty of introducing the predator to specific areas.
• C. The predator develops a preference to other diets and may itself become a pest.
• D. The predator does not always survive when transferred to a new environment.

Explanation: Insect enemies play an important role in nature for managing the phytophagous insect pests and keep a balance.

• A. Legumes fix nitrogen only through the specialized bacteria that live in their roots.
• B. Legumes fix nitrogen independently of the specialized bacteria that live in their roots.
• C. Legumes fix nitrogen only through specialized bacteria that live in their leaves.
• D. Legumes are incapable of fixing nitrogen.

Explanation: The nitrogen­-fixing ability of leguminous plants is not a property of the plants as such but results from infection of their roots by…

• A. Tendency of biological systems to change with change in the environment
• B. Tendency of biological systems to resist change
• C. Disturbance of self regulatory system and natural controls
• D. Biotic materials used in homeopathic medicines

Explanation: The ability to maintain a steady state within a constantly changing environment is essential for the survival of living systems.

• A. Aerenchyma-Opuntia
• B. Age pyramid-Biome
• C. Parthenium hysterophorus-Threat to biodiversity
• D. Stratification-Population

Explanation: Parthenium hysterophorus is commonly known as congress grass or carrot weed. It is a herbaceous annual plant of the Family Asteraceae.

• A. Both Azotobacter and Rhizobium fix atmospheric nitrogen in root nodules of plants.
• B. Cyanobacteria such as Anabaena and Nostoc are not important mobilizers of phosphates and for plant nutrition in soil.
• C. At present it is not possible to grow maize without chemical fertilizers.
• D. Extensive use of chemical fertilizers may lead to eutrophication of nearby water bodies.

Explanation: Eutrophication is the excessive growth of algae, plants, and animals in water bodies due to nutrient enrichment, particularly with…

• A. Anabaena and Nostoc are capable of fixing nitrogen in a free­living state also
• B. Root nodule-forming nitrogen fixers live as aerobes under free­living conditions
• C. Phosphorus is a constituent of cell membranes, certain nucleic acids, and all proteins
• D. Nitrosomonas and nitrobacteria are chemo­ autotrophs

Explanation: Phosphorus is present in the plasma membrane in the form of a phospholipid bilayer.

• A. Ecosystem and habitat diversity
• B. Species diversity and ecosystem diversity
• C. Species diversity, genetic diversity and ecosystem diversity
• D. Species diversity only

Explanation: c) Species diversity, genetic diversity, and ecosystem diversity:This is the correct answer.

• A. All the environmental factors that determine where an organism lives
• B. All the food webs in an ecosystem
• C. The place where an organism lives
• D. The role that a species fulfills in a community

Explanation: d) The role that a species fulfills in a community:This is the correct definition of niche.

• A. Complete
• B. Incomplete
• C. Almost complete
• D. None of these

Explanation: Ecosystems with abiotic components, producers, consumers, and decomposers are considered as complete ecosystems.

• A. Prevent entry of ultraviolet rays
• B. Prevent rainfall
• C. Prevent heat to escape
• D. All given options are correct

Explanation: Greenhouse gases are gases in Earth's atmosphere that trap heat. They let sunlight pass through the atmosphere, but they prevent the heat…

• A. Prairies
• B. Savana
• C. Boreal
• D. Pampas

Explanation: The Pampas in Argentina are most well known for the great biodiversity in the area.