Ecosystem Important Questions

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Very Short Answer Questions (1 Mark Questions)

Ques: What is the ultimate source of energy in the ecosystem?

Ans: Solar Radiation is the ultimate source of energy in the ecosystem.

Ques: The reduction in Gross Primary Productivity is caused by which process?

Ans: A metabolic process called Respiration is responsible for the reduction in the Gross Primary productivity.

Ques: Name three freshwater ecosystems.

Ans: Lakes, Ponds and Streams are three freshwater ecosystems

Ques: Give examples of man-made ecosystems.

Ans: Aquariums, National Parks, Gardens etc are examples of man-made systems.

Ques: An edible mushroom is an autotroph or heterotroph?

Ans: An edible mushroom is a heterotroph 

Ques: What are the two structural features of an ecosystem?

Ans: Stratification and Species composition are the two structural features of an ecosystem.

Ques: A rich diversity of macrophytes can be found in which two aquatic ecosystems?

Ans: A rich diversity of macrophytes can be found in lakes and wetlands.

Ques: List three terrestrial ecosystems.

Ans: Desert ecosystems, grasslands and Forests are the three terrestrial ecosystems.

Ques: What is the role of decomposers?

Ans: Decomposers break down dead organic matter into simpler substances.

Ques: What is Biodiversity?

Ans: Biodiversity refers to the variety of life in an ecosystem.

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Short Answer Questions (2 Marks Questions)

Ques: How has man interfered with the ecosystem? Give an example of the same.

Ans: Humans have impacted the environment in many ways which have resulted in soil erosion, climate change, poor air quality etc. Examples of the same are Deforestation, global warming, pollution, excessive production of waste, Construction of dams, etc.

Ques: How food is obtained from decomposition?

Ans: The enzymes are released by decomposers into the decaying and dead animal and plant remains. After this, the simple inorganic substance is absorbed by the decomposers which act as their food.

Ques: How net productivity is calculated?

Ans: The net productivity can be calculated by using the following formula:

Net Primary Productivity= Gross Productivity - Respiratory loss

Ques: What are the abiotic components of an ecosystem? List a few.

Ans: The non-living factors that impact an ecosystem are known as Abiotic Components or Abiotic Factors. 

Examples: 

1. Humidity
2. Precipitation
3. Altitude
4. Soil Type
5. Depth of Water
6. Penetration of Light
7. Wind
8. Climate

Ques: Define Eco-succession. What are the various types of Eco-succession?

Ans: In a biotic community, a continuous change is referred to as Eco-succession. The succession is categorized into two types mainly primary and secondary. The pre-existing conditions of a place define the pattern of succession of a community.

Three kinds of patterns that have been observed are as follows:

1. Hydrosere
2. Merosere
3. Xerosere

Ques: Explain mutualism with an example.

Ans: Mutualism is a symbiotic relationship where both species benefit. An example is the relationship between bees and flowering plants, where bees get nectar, and plants get pollination services.

Ques: What is Ecological Niche?

Ans:  An ecological niche refers to the role and position of a species in its environment, including how it obtains and utilizes resources, interacts with other species, and contributes to nutrient cycling.

Read More: Ecotone

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Long Answer Questions (3 Marks Questions)

Ques: What is an Ecosystem? How many types of ecosystems are there? List with examples.

Ans: An ecosystem consists of plants, animals and other microorganisms and the physical environment with which these interact. 

The ecosystem is broadly divided into three major categories which are as follows:

1. Terrestrial Ecosystem: All the ecosystems that are located on land are known as Terrestrial Ecosystems. It is categorized into Grassland, Tundra, desert and Forest ecosystems. The Grassland Ecosystem consists of Tropical and Temperature whereas Forest includes Taiga, Tropical and Temperature.
2. Aquatic Ecosystem: It refers to all the ecosystems that are located inside or on the water bodies. The Aquatic Ecosystem includes FreshWater Ecosystems (Ponds, springs, swamps, rivers, lakes) and Marine Ecosystems (seashore, ocean, Brackish)
3. Man-Made Ecosystem: An ecosystem which is created and then maintained by humans is called a Man-Made ecosystem. Parks and Gardens, spaceships, aquariums, Crop Fields, Animal Husbandry, small fishery tanks, Reservoirs and Dams are a few examples of a Man-Made ecosystem.

Ques: Explain the process of decomposition of detritus.

Ans: The following are the processes that are involved in the decomposition process of detritus:

1. Fragmentation: In this step, the Detrivore organism is broken down to detritus in small particles.
2. Leaching: The inorganic nutrients that are soluble in water seep inside the soil and then these get precipitated as unavailable salts.
3. Catabolism: The detritus is degraded by using the enzymes of fungus and bacteria into simple inorganic ions.
4. Humification: At a very slow rate, the process of formation of hummus takes place.
5. Mineralization: The microbes help to release the minerals from hummus in this last step.

Read More: Natural Ecosystem

Ques: Write in brief about the Food Chain and Food Web.

Ans: When one organism is consumed or eaten by another organism and then that organism is eaten by another organism, this order of events is referred to as the Food Chain. Every living thing needs food for its survival. The food chain is formed when energy or nutrients flow at different trophic levels from one organism to another. Decomposers play a vital role in the food chain as they help in the decomposition of dead animals and plants. They also help in the breakdown of the waste of other organisms. For primary producers, the continuous flow of nutrients is kept up by these decomposers. A food chain generally consists of four to five trophic levels. An organism from a higher trophic level can consume a single type of organism from the lower trophic level only.

The natural interconnection of the food chains is known as a Food Web. In a single ecosystem, all the food chains are a part of a Food Web. In a food web, an individual can consume more than one type of organism from the lower trophic level. 

Ques: Write down the differences between aquatic and terrestrial succession.

Ans: The differences between aquatic and terrestrial succession are:

Ques. Explain the concept of ecological succession in an ecosystem. Give examples.

Ans: Ecological succession is a natural process through which ecosystems undergo significant structural and compositional changes over time.

• It involves the sequential establishment of different plant and animal communities, leading to a mature and stable ecosystem.
• In primary succession, pioneer species, such as lichens and mosses, colonize barren landscapes devoid of soil, breaking down rocks and facilitating soil formation.
• Over time, more complex plant communities emerge, creating a conducive environment for diverse organisms.
• An example is the colonization of volcanic islands.
• Secondary succession occurs in areas where existing ecosystems have been disturbed by events like forest fires or human activities.
• Pioneer species, often annual plants and grasses, quickly recolonize the area.
• Over time, shrubs and trees were established, bringing about a more complex and stable ecosystem.
• An example is the regeneration of a forest after logging.

Biodiversity gradually increases throughout succession. Pioneer species create conditions for others to thrive, enhancing the overall resilience and ecological services of the ecosystem. 

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Very Long Answer Questions (5 Marks Questions)

Ques: List two main components of the ecosystem. What are the physical factors that affect the organisms' distribution in different habitats?

Ans: The two main components of an ecosystem are Biotic and Abiotic components. 

Physical factors (Abiotic Component) that affect the organisms' distribution in different habitats are as follows:

1. Water: An organism's dependency on water depends upon its requirements. The organisms which live in a dry habitat can conserve water very well like camels and cacti.
2. Humidity: The rate of evaporation from an organism’s surface can be affected by humidity. 
3. Water currents: It happens only in the streams or rivers and the organisms which are capable of avoiding strong currents or those who know swimming can survive.
4. Temperature: The change in environmental temperature can affect the biological and physiological adaptation of most animals.
5. Light: Essential for all the green plants for the process of photosynthesis and is also important for all the animals that are dependent on plants for food.
6. Wind and air currents: It is currently important for plants. In areas where winds are fierce, only plants with tough stems and strong root systems can live. The wind is also essential for the dispersal of seeds and spores.
7. Soil nutrients: The distribution of plants is affected by the presence of nutrients in the soil in which the plant grows.
8. Topography: The distribution of organisms is influenced by minor topographical differences. 
9. pH: The plant distribution in fresh-water ponds and soil is influenced by the pH level. Few plants can survive in acidic conditions and a few can survive in alkaline or neutral levels. Most of the plants are highly sensitive to the change in pH level of the soil.
10. Background: The distribution of creatures that blend in with their surroundings due to their shape or color is influenced by the environment's overall texture and pattern.

Read More: Interdependence of plants and animals

Ques: What is an Ecological Pyramid? Name three types of Ecological Pyramids. Write a few limitations of the ecological pyramid.

Ans: Ecological Pyramid refers to the graphical representation which shows the relationship between different types of organisms within the ecosystem. 

The three types of Ecological Pyramid are as follows:

1. Pyramid of Biomass: It represents the relationship between the consumers and producers in terms of biomass. The pyramid can be inverted or upright.
2. Pyramid of Energy: This pyramid represents the flow of energy in an ecosystem between producers and consumers, It is always upright. 
3. Pyramid of Number: The relationship between consumers and producers is represented in terms of number using a pyramid. The pyramid of numbers can either be inverted or upright. 

The limitations of the Ecological Pyramid are:

1. The ecological pyramid assumes a simple food chain. It also is not accountable for the food web.
2. From the Ecological Pyramid, Saprophytes are excluded.
3. The Ecological Pyramid is not accountable for the species 

Read More: Difference between grazing and detritus food chain

Ques: What is Carbon cycling in an ecosystem? List out the salient features of carbon cycling in an ecosystem. Mention a few reservoirs of carbon.

Ans: Nature's way of using the atoms of carbon that travel to the organisms in the Earth from the atmosphere and then go back to the atmosphere over and over again. Most of the carbon can be found in rocks and sediments while the rest of the carbon is stored in living organisms, the atmosphere and the ocean. 

A few reservoirs of carbon are as follows:

1. Carbon dioxide dissolved in water.
2. Bicarbonates present in oceans
3. Carbon dioxide present in the air.
4. Fossil fuels like petroleum and coal
5. Carbonates can also be found in the earth’s crust.

Salient features of the carbon cycling in an ecosystem are listed as below:

1. Utilization of Carbon dioxide: For the process of photosynthesis, green plants use carbon dioxide and as a by-product of this oxygen is released into the environment.
2. Production of Carbon dioxide and its return into the atmosphere:
   1. Carbon dioxide is released into the atmosphere through the burning of fossil fuels and wood. 
   2. Hot Springs and Volcanic eruptions can also release carbon dioxide into the atmosphere.
   3. The action of acids on the rocks which contain carbonate can result in its weathering which releases carbon dioxide.
   4. Due to the action of bacteria and fungi, the dead bodies and organic waste are decomposed by decomposers, and then carbon dioxide is released.

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