Fundamentals of Ecology & Ecosystems MCQ Questions
Ques:
21
Which of the following is an example of a decomposer?
Correct Answer:
(C)
Bacteria
Decomposers are organisms that break down dead organic matter, such as plants and animals, and return nutrients to the ecosystem. Bacteria and fungi are examples of decomposers
Ques:
22
The term Ecosystem was proposed by –
Correct Answer:
(D)
Sir Arthur George Tansley
The term ecosystem was first used by A. G. Tansley in 1935 who defined an ecosystem as ‘a particular category of physical systems, consisting of organisms and inorganic components in a relatively stable equilibrium, open and of various sizes and its kinds’. An Ecosystem is a community of living organism (plants, animals and microbes) along with the non-living components of their environment (like air, water, mineral, soil, etc.) interacting as a system. These biotic and abiotic components are considered as linked together through nutrient cycles and energy flows. As ecosystems are defined by the network of interactions among organisms and between organisms and their environment, these can vary in size from as small as a drop in the pond to as large as an ocean. The earth itself is a large ecosystem.
Note: There are four basic components of an ecosystem which include Abiotic materials, Producers, Consumers and Decomposers or Reducers. Whereas Producers, Consumers and Decomposers are included in a broad component, 'Biotic materials or 'Biotic Factors'.
Ques:
23
Which of the following is NOT true about the ecosystem?
Correct Answer:
(D)
It is a closed-system.
An ecosystem is a community of living organisms in conjunction with the non-living components of their environment (things like air, water and mineral soil), interacting as a system. Important features of ecology are:
It is normally an open system with a continuous, but variable influx and loss of materials and energy.
An ecosystem is an overall integration of the whole mosaic of the interacting organism and their environment.
It is a basic functional unit with no limits of boundaries.
It consists of biotic and abiotic components interacting with each other.
Its functional unit is capable of energy transformation, circulation and accumulation.
Different types of the ecosystem are present in different areas.
Ques:
24
Which one of the following is the best description of the term ‘ecosystem’?
Correct Answer:
(C)
A community of organisms together with the environment in which they live
All the organisms and the abiotic components of the environment form the ecosystem of the place. Thus, ecology deals with the organism and its environment.
Note: Ecotone is a region of transition between two biological communities.
Ques:
25
Which of the following is an artificial ecosystem?
Correct Answer:
(A)
Rice field
An artificial ecosystem meets all the criteria of a natural eco-system but is made and controlled by humans. Orchards, farmlands, gardens and human-made reservoirs are some examples of artificial ecosystems. Ecosystems can broadly be categorized as Aquatic and Terrestrial ecosystems. Grasslands, forests and deserts are examples of terrestrial ecosystems while lakes, rivers and oceans fall under aquatic Ecosystem. Notably, agriculture under human ecosystem has been instrumental to the existence of society and development. Hence (a) is the correct answer
Ques:
26
The number of organisms that can be supported by the environment in a given area is known as:
Correct Answer:
(B)
Carrying Capacity
The maximum population size that an ecosystem can support is called capacity carrying. capacity is the number of organisms that an ecosystem can sustainably support. Hence option (b) is correct.
Ques:
27
The actual location or place where an organism lives is called:
Correct Answer:
(A)
Habitat
The location or place where an organism lives is called a habitat. The organisms depend for their food, water, air, shelter and other needs on their habitat. A biome is a plant and animal community that covers a large geographical area. Some of the major biomes of the world are: forest, grassland, desert and tundra biomes.
Note: Ecological niche characterizes the position of a species within an ecosystem, comprising species habitat requirements as well as its functional role.
Ques:
28
Which one of the following ecosystems covers the largest area of the earth’s surface:
Correct Answer:
(D)
Marine Ecosystem
There are mainly two kinds of ecosystems- Aquatic and Terrestrial. Marine ecosystems are the biggest ecosystems, which cover around 71% of Earth’s surface and contain 97% of our planet’s water. Thus option (d) is the correct answer.
Note: Aquatic ecosystem refers to living and non-living parts of a water body and the interactions that take place among them. Aquatic ecosystems can be categorized in the marine ecosystem and freshwater ecosystem. Marine ecosystem covers approximately 71% of the earth's surface and contains approximately 97% of the planet's water.
Ques:
29
The highest trophic level in an ecosystem is obtained by:
Correct Answer:
(C)
Omnivores
There are four types of trophic levels in the food chain of the ecosystem. They are-
First trophic level- Producer
Second trophic level- Primary consumers (herbivorous)
Third trophic level- Secondary consumers (carnivorous)
Fourth trophic level- Tertiary consumers ( omnivorous)
Decomposers feed on all the above trophic levels. Hence option (c) is the correct answer.
Note: Solar energy is the primary source of energy in the ecological body. It is the driving force of an ecosystem.
Ques:
30
Which of the following is not a biotic component of an ecosystem?
Correct Answer:
(A)
Air
Biotic components are the living things that shape an ecosystem.
Biotic components usually include:
Producers: e.g. plants.
Consumers: e.g. animals, humans
Decomposers: e.g. fungi and bacteria