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Ecology

📆 September 25, 2024

Total Questions: 88

11. Which of the following is an artificial ecosystem? [Jharkhand P.C.S. (Pre) 2013]

Correct Answer: (b) Field
Solution:Field, garden are artificial ecosystem while forests, ponds and lakes are natural ecosystems.

Ecosystems, coined by Arthur Tansley in 1935, are dynamic systems where living organisms interact with their non-living environment. They vary in composition, species diversity, and non-biological components, involving energy flow and material cycling. It can be as large as the entire Biosphere itself or as small as a log of wood, each hosting the various components of the ecosystem interacting together.

The study of ecosystems focuses on their structure and function. These complex systems face threats that can degrade, fragment, or destroy them, impacting the delicate balance crucial for supporting life. Understanding these threats is vital for preserving biodiversity and the health of the ecosystems globally.

Ecosystems function through various processes and interactions between their biotic and abiotic components. These processes include the flow of energy and material (nutrients) among the components of the ecosystem, which are essential for maintaining the balance and sustainability of the ecosystem.

12. Consider the following statements relating to the ecosystem : [U.P.U.D.A./L.D.A. (Pre) 2002]

  1.   The term ecosystem was first used by A.G. Tansley.
  2.   Those organisms which produce their food themselves are termed as autotrophs.
  3.   Consumers consume their food through the process of photosynthesis.
  4.   Decomposers convert inorganic matter into organic matter.

Which of the above statements are correct :

Correct Answer: (a) 1 and 2
Solution:The term ecosystem was first used by A.G. Tansley. Hence statement (1) is correct. Biotic components are the living things that shape an ecosystem. Autotrophic components are self-feeding organisms of the ecosystem. These produce their food themselves. Hence statement (2) is also correct. Consumers are organisms of an ecological food chain which receive energy by consuming other organisms. These organisms are formally referred to as heterotrophs. Hence, statement (3) is wrong. Organic matter is recycled in an ecosystem by decomposers. Decomposers are organisms such as bacteria and fungi that break down the organic matter of the dead bodies of plants and animals into inorganic material. Hence statement (4) is also wrong.

13. What is true about ecosystem? [U.P.P.C.S. (Pre) 2019]

Correct Answer: (c) Producers are more than primary consumers
Solution:In a given ecosystem, these are generally more producers than primary consumers, and more primary consumers than secondary consumers, and so on. Ecosystems, coined by Arthur Tansley in 1935, are dynamic systems where living organisms interact with their non-living environment. They vary in composition, species diversity, and non-biological components, involving energy flow and material cycling. It can be as large as the entire Biosphere itself or as small as a log of wood, each hosting the various components of the ecosystem interacting together.

The study of ecosystems focuses on their structure and function. These complex systems face threats that can degrade, fragment, or destroy them, impacting the delicate balance crucial for supporting life. Understanding these threats is vital for preserving biodiversity and the health of the ecosystems globally.

Ecosystems function through various processes and interactions between their biotic and abiotic components. These processes include the flow of energy and material (nutrients) among the components of the ecosystem, which are essential for maintaining the balance and sustainability of the ecosystem.

14. Given below are two statements, one is labelled as Assertion (A) and other as Reason (R) [U.P.P.C.S. (Pre) 2021]

Assertion (A)  : Various components of an ecosystem are not interdependent.

Reason (R)      : Human activities have the impacts on the environment.

Select the correct answer using the codes given below Codes :

Correct Answer: (d) (A) is false, but (R) is true
Solution:All organisms in an ecosystem depend upon each other. If the population of one organism rises or falls, then this can affect the rest of the ecosystem. If the foxes in the food chain above were killed, the population of rabbits would increase because they are no longer prey to the foxes. Humans impact the physical environment in many ways: overpopulation, pollution, burning fossil fuels, and deforestation.

15. Which of the following is an artificial ecosystem? [U.P.P.C.S. (Pre) 2016]

Correct Answer: (a) Rice field
Solution: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.

16. Which one of the following ecosystems covers the largest area of the earth's surface : [U.P. Lower Sub. (Spl) (Pre) 2003]

Correct Answer: (d) Marine Ecosystem
Solution:There are mainly two kinds of ecosystem-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. Ecosystems, coined by Arthur Tansley in 1935, are dynamic systems where living organisms interact with their non-living environment. They vary in composition, species diversity, and non-biological components, involving energy flow and material cycling. It can be as large as the entire Biosphere itself or as small as a log of wood, each hosting the various components of the ecosystem interacting together.

The study of ecosystems focuses on their structure and function. These complex systems face threats that can degrade, fragment, or destroy them, impacting the delicate balance crucial for supporting life. Understanding these threats is vital for preserving biodiversity and the health of the ecosystems globally.

Ecosystems function through various processes and interactions between their biotic and abiotic components. These processes include the flow of energy and material (nutrients) among the components of the ecosystem, which are essential for maintaining the balance and sustainability of the ecosystem.

17. Which one of the following is the largest ecosystem of the world? [U.P.P.C.S. (Pre) 2014]

Correct Answer: (a) Ocean
Solution:Marine ecosystems encompass oceans, coral reefs, and deep-sea environments, known for their saline waters and wide range of biodiversity. Marine ecosystem covers approximately 71% of the earth's surface and contains approximately 97% of the planet's water.
  • Oceans: The Pacific Ocean is the largest and deepest on Earth and has a vital role in Earth's climate and weather system.
  • Corals: There are the Great Barrier Reefs, that hold some of the thousands of different marine species, and make the ecosystem rich in biodiversity.
  • Estuaries: Some are located in areas such as Chesapeake Bay where fresh water flows into saltwater, hence it creates the richest productive environments.

An aquatic ecosystem is a water-based environment where the relationships between living things and other living things along with abiotic components could be traced. Aquatic ecosystems include freshwater and marine ecosystems; the latter pertains to the salinity of water. Freshwater ecosystems would include lakes, rivers, streams, and ponds while marine ecosystems will include oceans, coral reefs, and estuaries. The critical aspect of aquatic ecosystems is their dependence on water as a medium that affects the chemical reactions and offers stability to habitats.

Brackish water ecosystems, such as estuaries and mangrove swamps, have salt levels between freshwater and marine ecosystems, supporting unique plant and animal communities.

  • Estuaries: San Francisco Bay- a crucial habitat for the diverse species that have been adapted to varying salinity
  • Mangroves: Mekong Delta is an important breeding ground for fish and crustaceans.

18. Which is the most stable ecosystem? [U.P.P.C.S. (Pre) 2018]

Correct Answer: (a) Marine (ocean)
Solution:Marine ecosystems encompass oceans, coral reefs, and deep-sea environments, known for their saline waters and wide range of biodiversity. Marine ecosystem covers approximately 71% of the earth's surface and contains approximately 97% of the planet's water.
  • Oceans: The Pacific Ocean is the largest and deepest on Earth and has a vital role in Earth's climate and weather system.
  • Corals: There are the Great Barrier Reefs, that hold some of the thousands of different marine species, and make the ecosystem rich in biodiversity.
  • Estuaries: Some are located in areas such as Chesapeake Bay where fresh water flows into saltwater, hence it creates the richest productive environments.

An aquatic ecosystem is a water-based environment where the relationships between living things and other living things along with abiotic components could be traced. Aquatic ecosystems include freshwater and marine ecosystems; the latter pertains to the salinity of water. Freshwater ecosystems would include lakes, rivers, streams, and ponds while marine ecosystems will include oceans, coral reefs, and estuaries. The critical aspect of aquatic ecosystems is their dependence on water as a medium that affects the chemical reactions and offers stability to habitats.

Brackish water ecosystems, such as estuaries and mangrove swamps, have salt levels between freshwater and marine ecosystems, supporting unique plant and animal communities.

  • Estuaries: San Francisco Bay- a crucial habitat for the diverse species that have been adapted to varying salinity
  • Mangroves: Mekong Delta is an important breeding ground for fish and crustaceans.

19. Which among the following is the most stable ecosystem? [M.P.P.C.S. (Pre) 2023]

Correct Answer: (c) Marine ecosystem
Solution:Marine ecosystems encompass oceans, coral reefs, and deep-sea environments, known for their saline waters and wide range of biodiversity. Marine ecosystem covers approximately 71% of the earth's surface and contains approximately 97% of the planet's water.
  • Oceans: The Pacific Ocean is the largest and deepest on Earth and has a vital role in Earth's climate and weather system.
  • Corals: There are the Great Barrier Reefs, that hold some of the thousands of different marine species, and make the ecosystem rich in biodiversity.
  • Estuaries: Some are located in areas such as Chesapeake Bay where fresh water flows into saltwater, hence it creates the richest productive environments.

An aquatic ecosystem is a water-based environment where the relationships between living things and other living things along with abiotic components could be traced. Aquatic ecosystems include freshwater and marine ecosystems; the latter pertains to the salinity of water. Freshwater ecosystems would include lakes, rivers, streams, and ponds while marine ecosystems will include oceans, coral reefs, and estuaries. The critical aspect of aquatic ecosystems is their dependence on water as a medium that affects the chemical reactions and offers stability to habitats.

Brackish water ecosystems, such as estuaries and mangrove swamps, have salt levels between freshwater and marine ecosystems, supporting unique plant and animal communities.

  • Estuaries: San Francisco Bay- a crucial habitat for the diverse species that have been adapted to varying salinity
  • Mangroves: Mekong Delta is an important breeding ground for fish and crustaceans.

20. Which one of the following is not a sub-category of terrestrial ecosystem? [U.P.R.O./A.R.O. (Mains) 2021]

Correct Answer: (b) Marine ecosystem
Solution:Scientists divide ecosystems into terrestrial (land ecosystem) and non-terrestrial (non-land ecosystem). Ecosystems may be further classified by their geographical region and dominant plant type. Aquatic, marine, and wetlands constitute the non-terrestrial ecosystems, while the five major terrestrial ecosystems are desert, forest, grassland, taiga and tundra.
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