Our Environment – Very Short Answer Type Questions
CBSE Class 10 Biology — Chapter 13: Our Environment — 60 Very Short Questions & Answers
Class: CBSE Class 10
Subject: Science — Biology
Chapter: Chapter 13 — Our Environment
CBSE Board Examinations
Systematic order: Syllabus → Key concepts → Topic-wise Q&A → Quick revision
Instructions: 60 topic-wise very short answer questions with concise answers strictly aligned to NCERT Class 10 Biology — Chapter 13: Our Environment. Use for rapid revision, tests and board preparation.
Contents: Basics & Ecosystems (Q1–10) • Food chains, webs & pyramids (Q11–20) • Energy & nutrient cycles (Q21–30) • Biodiversity & conservation (Q31–40) • Pollution (Q41–50) • Waste management & practical (Q51–60).
Basics & Ecosystem Concepts (Q1–10)
1
What is an ecosystem?
A functional unit of interacting organisms and their physical environment.
2
Name two abiotic components.
Sunlight and water (also soil, temperature, air).
3
What are producers?
Autotrophs (mainly green plants) that make food by photosynthesis.
4
Give an example of a decomposer.
Fungi or bacteria (e.g., Rhizopus, Pseudomonas).
5
Define a community.
All interacting populations of different species in an area.
6
What is a habitat?
The natural place where an organism lives.
7
What is an ecological niche?
The role and position an organism has in its environment (how it meets needs).
8
Define population.
A group of individuals of the same species living in a given area.
9
What is biosphere?
The global zone of life where living organisms exist (land, water, air).
10
Why are decomposers important?
They recycle nutrients by breaking down dead matter into inorganic forms.
Food Chains, Food Webs & Ecological Pyramids (Q11–20)
11
What is a food chain?
A linear sequence of organisms showing transfer of energy from producer to consumers.
12
Example of a simple food chain in a pond.
Algae → Small fish → Big fish → Kingfisher.
13
What is a food web?
Interconnected food chains showing multiple feeding relationships.
14
Define trophic level.
A feeding level in a food chain (producer = 1st trophic level).
15
What is a pyramid of numbers?
A pyramid showing number of organisms at each trophic level.
16
Why is pyramid of energy always upright?
Because energy decreases at each higher trophic level (energy loss as heat).
17
What does pyramid of biomass represent?
Total dry mass of organisms at each trophic level.
18
Give one reason food chains are short.
Energy loss (~90% lost) limits number of trophic levels.
19
What is biomagnification?
Increase in concentration of toxins at successive trophic levels.
20
Example of biomagnifying pollutant.
DDT or mercury (methylmercury).
Energy Flow & Nutrient Cycles (Q21–30)
21
Source of nearly all energy in ecosystems?
The Sun (solar energy).
22
Define photosynthesis in one line.
Process by which green plants convert CO₂ and water into glucose using sunlight.
23
What procent of energy transfers to next trophic level (approx.)?
About 10% (rule of thumb).
24
Major reservoir of carbon in short term?
Atmospheric CO₂ and living organisms.
25
Name a nitrogen-fixing symbiont.
Rhizobium (in legume root nodules).
26
What is nitrification?
Conversion of ammonia → nitrite → nitrate by bacteria.
27
What is denitrification?
Conversion of nitrate back to N₂ gas by denitrifying bacteria.
28
Role of decomposers in nutrient cycles?
Break down organic matter, releasing inorganic nutrients to soil/air.
29
One human activity that increases atmospheric CO₂.
Burning fossil fuels (coal, oil, gas).
30
Why is carbon cycle important?
It regulates atmospheric CO₂ and supports life through organic compound formation.
Biodiversity & Conservation (Q31–40)
31
Define biodiversity briefly.
Variety of life at genetic, species and ecosystem levels.
32
One reason biodiversity is useful to humans.
Provides resources (food, medicine) and ecosystem services.
33
Name a protected area type in India.
National Park or Wildlife Sanctuary.
34
What is afforestation?
Planting trees in areas not previously forested to increase forest cover.
35
One cause of biodiversity loss.
Habitat destruction (deforestation, urbanisation).
36
What is an invasive species?
A non-native species that spreads and harms native ecosystems.
37
Role of wildlife corridors?
Connect fragmented habitats to allow animal movement and gene flow.
38
Name one international agreement for biodiversity/ozone protection.
Montreal Protocol (ozone), Convention on Biological Diversity (CBD).
39
What is ex-situ conservation?
Conserving species outside natural habitats (zoos, seed banks).
40
One simple way students can help conserve biodiversity.
Plant native trees and avoid single-use plastics.
Pollution — Types, Sources & Effects (Q41–50)
41
Define pollution in one line.
Introduction of harmful substances into the environment causing adverse effects.
42
Two main sources of air pollution.
Vehicle emissions and industrial smokestacks.
43
What causes acid rain?
Sulphur dioxide (SO₂) and nitrogen oxides (NOx) forming acids in rainwater.
44
One effect of water pollution on aquatic life.
Eutrophication leading to oxygen depletion and fish kills.
45
What is biomagnification—short?
Toxin concentration increases up the food chain.
46
Give an example of a biodegradable pollutant.
Food waste (biodegradable organic matter).
47
Give an example of a non-biodegradable pollutant.
Plastic, DDT.
48
What is noise pollution? One effect.
Excessive sound causing hearing loss and stress.
49
How does thermal pollution affect water bodies?
Raises temperature, reduces dissolved oxygen, harms aquatic organisms.
50
One measure to reduce vehicular air pollution.
Use public transport and promote cleaner fuels/EVs.
Waste Management & Practical Points (Q51–60)
51
What are the '3 Rs' of waste management?
Reduce, Reuse, Recycle.
52
Why segregate waste at source?
To enable effective recycling and safe disposal of hazardous wastes.
53
One benefit of composting organic waste.
Produces nutrient-rich manure for soil improvement.
54
What is sanitary landfill?
Engineered site for safe disposal of solid wastes with measures to prevent pollution.
55
Name one method to treat sewage.
Biological treatment (activated sludge, septic tanks) or filtration and disinfection.
56
One practical classroom action to reduce waste.
Use digital handouts, avoid single-use plastics and recycle paper.
57
How can planting trees help control air pollution?
Trees absorb CO₂ and particulates and release oxygen; they filter pollutants.
58
What is an eco-friendly habit related to water use?
Use drip irrigation, fix leaks, and harvest rainwater.
59
Why teach environment topics in school?
To build awareness for conservation and sustainable living from young age.
60
One sentence summarising 'Our Environment'.
A balanced system of living and non-living components that must be conserved for future generations.