The following 20 Multiple Choice Questions (MCQ) are based on
Chapter 12: How Nature Works in Harmony from the NCERT Class 8
Science textbook Curiosity. Each question has four options - select the
best answer and click to check.
Instructions: Read each question carefully. Choose the most
appropriate option from (a), (b), (c), or (d). Click
Show Answer to reveal the correct answer with explanation.
Multiple Choice Questions
1A habitat is:
(a) The place where an organism lives
(b) Only a large forest
(c) A group of one species
(d) A non-living object
(a) is correct
A habitat supplies conditions and resources needed by an organism.
2Which is an abiotic component of an ecosystem?
(a) Grass
(b) Fungus
(c) Deer
(d) Sunlight
(d) is correct
Abiotic components are non-living factors such as light, water, soil and temperature.
3Which is a biotic component?
(a) Air
(b) Rock
(c) Bacterium
(d) Rainfall
(c) is correct
Biotic components are living organisms.
4A group of individuals of the same species living in an area is a:
(a) Habitat
(b) Population
(c) Community
(d) Ecosystem
(b) is correct
For example, all deer of one species in a forest form a population.
5All interacting populations in an area form a:
(a) Community
(b) Individual
(c) Mineral
(d) Climate
(a) is correct
A community includes the populations of plants, animals, fungi and microbes.
6An ecosystem includes:
(a) Only plants
(b) Only predators
(c) One individual
(d) A community and its abiotic environment
(d) is correct
Living organisms interact with each other and with non-living surroundings.
7Green plants are called producers because they:
(a) Decompose all waste
(b) Produce only carbon dioxide
(c) Make food using sunlight
(d) Consume other organisms
(c) is correct
Photosynthesis captures solar energy in organic food.
8Animals that eat plants directly are:
(a) Abiotic factors
(b) Primary consumers
(c) Producers
(d) Decomposers
(b) is correct
Herbivores obtain energy from producers and occupy the next trophic level.
9A food chain shows:
(a) A pathway of food and energy transfer
(b) Only water movement
(c) Every mineral in soil
(d) One organism's body parts
(a) is correct
Arrows link organisms according to who eats whom and the direction of energy transfer.
10A food web is more realistic than a single food chain because:
(a) Every organism eats only one thing
(b) It excludes decomposers
(c) It has no producers
(d) Organisms usually have multiple feeding links
(d) is correct
Interconnected chains reflect alternative food sources and predators.
11Decomposers such as fungi and bacteria:
(a) Produce sunlight
(b) Eat only living plants
(c) Break down dead matter and recycle nutrients
(d) Stop nutrient return
(c) is correct
Decomposition makes nutrients available again to producers.
12In mutualism:
(a) Both are always harmed
(b) Both interacting species benefit
(c) One benefits and the other is harmed
(d) Neither is affected
(b) is correct
Examples include pollinators receiving food while helping plants reproduce.
13In parasitism:
(a) One organism benefits while the host is harmed
(b) Both organisms benefit
(c) One eats and immediately kills prey
(d) No organism is affected
(a) is correct
A parasite obtains resources from a living host at the host's expense.
14Predation occurs when:
(a) Both organisms make food
(b) Two organisms share shelter without effect
(c) A plant absorbs sunlight
(d) One organism captures and eats another
(d) is correct
The predator benefits by consuming prey.
15Competition occurs when organisms:
(a) Have unlimited resources
(b) Belong only to different kingdoms
(c) Require the same limited resource
(d) Always cooperate
(c) is correct
Limited food, water, space or mates can lead organisms to compete.
16Wildlife corridors help elephants by:
(a) Increasing conflict with settlements
(b) Connecting separated habitats for safer movement
(c) Preventing every migration
(d) Replacing all forests with farms
(b) is correct
Corridors maintain routes between habitat patches and reduce dangerous encounters.
17Removing a top predator may cause:
(a) A cascade of changes across the food web
(b) No change anywhere
(c) Only more sunlight
(d) Immediate disappearance of soil
(a) is correct
Predator loss can alter prey numbers, vegetation and many indirect interactions.
18Which is an ecosystem service?
(a) Permanent removal of soil fertility
(b) Loss of clean water
(c) Habitat destruction
(d) Pollination of crops
(d) is correct
Healthy ecosystems provide benefits such as pollination, clean water and nutrient cycling.
19A crop field is considered a human-made ecosystem because:
(a) It contains no soil
(b) It receives no sunlight
(c) People manage its organisms and conditions
(d) It has no living organisms
(c) is correct
Farmers choose crops and manage water, nutrients, pests and other interactions.
20Greater biodiversity often supports ecosystem stability because:
(a) Decomposition stops
(b) Multiple species can perform connected or overlapping roles
(c) All species become identical
(d) Food webs become a single link
(b) is correct
Diverse interactions can help ecological functions continue when conditions change.
