NTSE Biology Environment MCQs

Question: Ecology is the study of relationship between

• a) Water and environment
• b) Organisms and environment
• c) Solid and water
• d) All of the above

Answer: Organisms and environment

Question: Soil fertility is reduced by

• a) Crop rotation
• b) Nitrogen fixing bacteria
• c) Decrying organic matter
• d) Intensive agriculture

Answer: Intensive agriculture

Question: The main cause of soil erosion is

• a) Afforestation
• b) Less rains
• c) Thinning of ozone layer
• d) Deforestation

Answer: Deforestation

Question: World climate is threatened by increase in concentration of

• a) Oxygen
• b) Carbon dioxide
• c) Nitrogen
• d) Water vaporous

Answer: Carbon dioxide

Question: Which one of the following forms a toxic substance in blood by combining with hemoglobin ?

• a) CO
• b) CO2
• c) CH4
• d) O2 

Answer: CO

Question: Biological O2 demand measures

• a) Industrial pollution
• b) Dissolved oxygen needed by microbes
• c) Polluting capacity of effluents
• d) Air pollution

Answer: Dissolved oxygen needed by microbes

Question: The production of useful aquatic plants and animals by using various types of water resources is called

• a) Aquaculture
• b) Pisciculture
• c) Silviculture
• d) Silver revolution

Answer: Aquaculture

Question: Primary source of energy in an ecosystem is

• a) Sugar stored in plants
• b) Heat liberated during respiration
• c) Solar energy
• d) Heat liberated by fuel burning

Answer: Solar energy

Question: Ozone hole refers to

• a) Hole in ozone layer
• b) Reduction in thickness of ozone layer in stratosphere
• c) Reduction in thickness of ozone layer in troposphere
• d) Increase in concentration of ozone

Answer: Reduction in thickness of ozone layer in stratosphere

Question: Eutrophication leads to death of fish due to

• a) Increased O2 content      
• b) Increased algal content
• c) Decreased algal content
• d) Decreased O₂ content

Answer: Decreased O₂ content

More Questions...................

Question: Basic unit of ecological hierarchy is

• a) Ecosystem
• b) Biological community
• c) Population
• d) Individual

Answer: Individual

Question: Autecology is study of ecology of

• a) Individual
• b) Population
• c) Species
• d) Both B and C

Answer: Individual

Question: The highest level of ecological hierarchy is

• a) Ecosystem
• b) Biosphere
• c) Biome
• d) Landscape

Answer: Biosphere

Question: Most abundant Noble gas of the atmosphere is

• a) Neon
• b) Xenon
• c) Argon
• d) Crypton

Answer: Argon

Question: Soil best suited for plant growth is

• a) Clay
• b) Loam
• c) Sandy
• d) Gravel

Answer: Loam

Question: The sphere of living matter found on the surface of earth comprises

• a) Lithosphere
• b) Hydrosphere
• c) Atmosphere
• d) Biosphere

Answer: Biosphere

Question: Components of environment are

• a) Biotic
• b) Abiotic
• c) Resources and regulatory factors
• d) All of the above

Answer: All of the above

Question: Humus defined as

• a) Physical texture of soil
• b) Chemical composition of soil
• c) Decomposed organic matter is soil
• d) None of these

Answer: Decomposed organic matter is soil

Question: Palisade parenchyma is well developed in

• a) Mesophytes
• b) Xerophytes
• c) Sciophytes
• d) Hygrophytes

Answer: Mesophytes

Question: In cacti the succulents are mostly

• a) Stems
• b) Leaves
• c) Roots
• d) All of the above

Answer: Stems

Question: An adjustment of camels to desert condition

• a) Maintenance of blood stream moisture
• b) Minimization of body heating
• c) Tolerance of cell dehydration up to 40%
• d) All of the above

Answer: All of the above

Question: Submerged hydrophytes have commonly dissected leaves for

• a) Decreasing surface area
• b) Increasing surface area
• c) Reducing effect of water currents
• d) Increasing number of stomata

Answer: Reducing effect of water currents

Question: Submerged shydrophytes exchange gases through

• a) Stomata
• b) Hydathodes
• c) Lenticels
• d) General surface

Answer: General surface

Question: Which on is exclusively xerophytes adaptation ?

• a) Absence of stomata
• b) Long tap root system
• c) Stipular leaves
• d) Spines

Answer: Spines

Question: Mark of odd one out

• a) Pistia
• b) Hydrilla
• c) Vallisneria
• d) Casuarina

Answer: Casuarina