Plant biomass is
Correct answer D. Both b and c
Topic / 27 questions
Ecosystem MCQs
Ecosystem MCQs test how organisms interact with each other and with their non-living surroundings, covering habitats, biomes, symbiotic relationships and ecological succession. They support MDCAT, NEET UG and medical admission candidates revising ecology. Each question shows an instant answer, so you can confirm key definitions and examples quickly.
- Biological Molecules 74
- Coordination and Control 72
- Biology Diagnostic 70
- Cell Structure and Function 67
- Biotechnology 65
- Reproduction 58
- Bioenergetics 55
- Circulation 50
- Inheritance 48
- Digestion 45
- Immunity 45
- Support and Movement 45
- Acellular Life (Viruses) 45
- Homeostasis 45
- Respiration and Gaseous Exchange 45
- Evolution 45
- Enzymes 45
- Cell Cycle 41
- Chromosome and DNA 40
- Biology Introduction 38
- Ecosystem 27
Gross primary production is
Correct answer C. Total amount of energy fixed by all plants \
Oxidation of ammonia or ammonium ions by bacteria in soil is called
Correct answer A. Nitrification
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Nitrogen constitutes about ____ % of atmosphere
Correct answer D. 78%
Over grazing leads to
Correct answer C. Totally barren lands
Sharks may have small fish attached to them called
Correct answer D. Remoras
Symbiosis relationship in which only one organism is benefited is
Correct answer B. Commensalism
A dual organism composed of symbiotic association of an alga living within a fungus myceliium is
Correct answer C. Lichen
Legume plants are the hosts to
Correct answer A. Rhizobium
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Disease in living organisms caused by parasites is called
Correct answer B. Infestation
Wood forests form the
Correct answer B. Climax community
Mosses are
Correct answer C. Tortula
Hydrosere is
Correct answer B. Primary succession starting in a pond
Secondary succession starts from
Correct answer C. From remains of previous ecosystem
Diverse and stable community at the end of succession is
Correct answer A. Climax community
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Lichen and algae form
Correct answer B. Pioneers community
Plants growing in xeric conditions are called
Correct answer C. Xerophytes
Sequence of changes in community and its non-living environment over a period of time is
Correct answer B. Succession
Which statement about the ecosystem is true?
Correct answer C. Fungi and bacteria are decomposers
Abiotic components include
Correct answer D. All of these
About Ecosystem MCQs
This ecology chapter focuses on the vocabulary of living systems. Questions distinguish a habitat, the actual place where an organism lives, from its niche, and define a biome as a major regional community such as a forest or grassland. Symbiosis features strongly: lichens as a partnership between an alga and a fungus, nitrogen-fixing bacteria living in legume root nodules, and remoras attached to sharks as an example of commensalism. You will also see succession, the gradual sequence of community change over time, including the role of lichens as pioneer species.
Exams that include Ecosystem MCQs
Pakistan
- MDCAT
- ETEA
- NTS
India
- NEET UG
- CUET
Bangladesh
- Medical admission test (MBBS)
- University admission tests (DU, RU, JU)
Frequently asked questions
What is a lichen?
A lichen is a dual organism formed by a symbiotic association between a fungus and an alga or cyanobacterium. The alga makes food by photosynthesis while the fungus provides shelter, water and minerals. Lichens are often the first colonisers of bare rock in ecological succession.
What is the difference between a habitat and a niche?
A habitat is the physical place where an organism lives, such as a pond or forest floor. A niche is the organism's role in that ecosystem, including what it eats, when it is active and how it interacts with other species. Two species rarely share exactly the same niche.
How many Ecosystem MCQs are on MCQs360?
There are 27 Ecosystem MCQs on MCQs360, each with an instant answer and free to practise with no sign-up. Make a short list of symbiosis examples with their type before starting, as these produce many of the trickier options.
Last reviewed October 2026