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Ecosystem & its Types: NBSE Class 9 Environment
Get summaries, questions, answers, solutions, notes, extras, PDF and guide of Chapter 1 Ecosystem & its Types, NBSE Class 9 Environmental Education textbook, which is part of the syllabus of students studying under Nagaland Board. These solutions, however, should only be treated as references and can be modified/changed.
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Summary
An ecosystem is a self-sufficient unit where living and non-living things interact with each other. The word “ecosystem” comes from two parts: “Eco,” which means environment, and “system,” which refers to the way things are connected. Ecosystems can be natural or artificial. Natural ecosystems are those that exist in nature without human interference, while artificial ones are created by humans.
The Earth has different types of ecosystems like forests, grasslands, deserts, and aquatic areas. Forests are home to many trees and animals. They are found in different climates, such as tropical rainforests, temperate forests, and deciduous forests. Each type of forest has its own plants and animals. Grasslands are areas where grasses are the main plants. These areas receive low to moderate rainfall. Deserts are dry places with very little rain. Plants and animals here have special ways to survive in harsh conditions.
Aquatic ecosystems are water-based and cover more than 70% of the Earth’s surface. These include rivers, lakes, ponds, and oceans. Freshwater ecosystems have less salt, while marine ecosystems, like oceans, have high salt levels. Marshes and swamps are also part of aquatic ecosystems. Marshes have grassy plants, while swamps are filled with trees and shrubs. Lakes are larger and deeper than ponds and have different layers of life depending on how much sunlight reaches them.
Coastal ecosystems are found where land meets the sea. This area changes with the tides and is home to organisms that can handle both water and land. Estuaries are special areas where rivers meet the sea. They are rich in nutrients and support many plants and animals. Marine ecosystems are divided into zones based on depth and light. The neritic zone is shallow and gets lots of sunlight, while the benthic zone is deep and dark.
Artificial ecosystems are made by humans. Examples include crop fields, aquariums, and parks. These mimic natural ecosystems but are controlled by people. The interaction between living and non-living parts of an ecosystem is important. Living parts are called biotic components, like plants, animals, and microorganisms. Non-living parts are abiotic components, like air, water, soil, and sunlight. Both biotic and abiotic parts depend on each other. For example, plants need sunlight and water to grow, while animals depend on plants for food.
When plants and animals die, decomposers like bacteria and fungi break them down. This releases nutrients back into the soil. Temperature, humidity, and wind also affect ecosystems. Each ecosystem has unique features that help specific plants and animals survive. Understanding these interactions helps us learn how ecosystems work and why they are important for life on Earth.
Textbook solutions
Multiple Choice Questions (MCQs)
1. The most diverse ecosystem on the earth surface is
(a) Grassland (b) Marine (c) Desert (d) Rainforest
Answer: (d) Rainforest.
2. Plant life of deserts is well adapted to
(a) Heat (b) Water (c) Dry condition and daytime heat (d) None of these
Answer: (c) Dry condition and daytime heat.
3. Aquatic ecosystems occupy more than……..of the earth surface.
(a) 80% (b) 70% (c) 85% (d) 75%
Answer: (b) 70%
4. Ecosystem of seas and oceans is called
(a) Marine Ecosystem (b) Coastal ecosystem (c) Forest ecosystem (d) Grasslands
Answer: (a) Marine Ecosystem.
5. The area where river joins the sea in one channel only is called
(a) Ocean (b) Lake (c) Estuary (d) None of these
Answer: (c) Estuary
6. The structural and functional unit of the biosphere is
(a) Atmosphere (b) Ecosystem (c) Hydrosphere (d) Lithosphere
Answer: (b) Ecosystem
Very Short Answer Questions
1. Define ecosystem.
Answer: Ecosystem is defined as the area in which communities interact with each other as well as with their surrounding environment.
2. What is biosphere?
Answer: The biosphere is the part of the earth where living organisms exist.
3. What do you understand by biome?
Answer: A biome is a life zone consisting of plants, animals, microorganisms and their physical environment.
4. What are forests?
Answer: Forests are a natural growing plant community of trees and other woody vegetation which occupies a large area.
5. Define natural ecosystem.
Answer: Natural ecosystems are those ecosystems which are under the control of nature.
6. Define artificial ecosystem.
Answer: Artificial ecosystems are man-made ecosystems, including crop fields, artificial lakes and ponds, aquariums, water bodies, etc.
Short Answer Questions
1. What is terrestrial ecosystem? Give three examples.
Answer: A terrestrial ecosystem refers to the ecosystem of land. Examples include forests, grasslands, and deserts
2. Give two features of tropical rainforests.
Answer: The average annual temperature remains above 17°C.Such conditions favor the growth of thick and dense evergreen forests
3. What type of plants and animals are found in the temperate evergreen forests?
Answer: Plants: Sunlight can easily penetrate the canopy of these trees, so ground vegetation is well-developed in the form of epiphytes.
Animals: Animals that inhabit these forests include puma, jaguar, and bear
4. What are abiotic components?
Answer: Abiotic components are the non-living components of an ecosystem, including air, soil, water, sunlight, temperature, rainfall, and wind.
5. What type of vegetation grows in the grasslands?
Answer: Grass, sedge, and forage plants are the main vegetation in the grasslands
6. Mention two features of the desert vegetation.
Answer: Plant life of deserts is well-adapted to dry conditions and daytime heat. Woody plants have deep roots and are able to absorb water from depth
7. What are marshes? Name important marshy area of India.
Answer: Marshes are the flooded areas that are characterized by non-woody plants like grasses, rushes, reeds, typhas, sedges, and other herbaceous plants. An important marshy area of India is the Rann of Kutch
8. What type of vegetation grows in swamp? Name one famous swamp of India.
Answer: In swamps, the vegetation is dominated by trees and shrubs. One famous swamp of India is the Konalar near Kodaikanal
9. What are biotic components?
Answer: Biotic components are the living things that shape the ecosystem, including producers, consumers, and decomposers
10. How are animals able to maintain their position in the flowing water?
Answer: Animals are able to maintain their position in the flowing water by having adaptations such as streamlined bodies, strong muscles, and specialized structures like fins or suckers that help them resist the water current and stay in place.
11. Give two features of the esturian ecosystem.
Answer: Two features of the estuarine ecosystem are:
- Estuaries remains full of producers, consumers and the decomposers i.e., various species of sea-weeds, algae and other plants (producers).
- High productivity is the main feature of this zone. People living around this area catch a large number of fish.
12. Mention two reasons for the variety of organisms in coastal ecosystem.
Answer: The organisms of this zone are subjected to a great deal of variation due to being alternately submerged and exposed because of tides. Waves add to the battering of these organisms, leading to adaptation and diversity.
13. Define benthic ecosystem.
Answer: “The term ‘benthic ecosystem’ refers to anything (biological and non-living) that is associated with the bottom of a body of water.”
14. Define artificial ecosystem. Give its examples.
Answer: Artificial ecosystems are man-made ecosystems. These includes crop fields, artificial lakes and ponds, aquariums, water bodies, etc.
Examples of artificial ecosystems are:
Aquarium: An aquarium is defined as a container such as a glass tank or an artificial pond in which living aquatic animals or small plants are kept.”
Park: A park or little garden is a man-made ecosystem in our back yards is best example for man-made terrestrial ecosystem.
15. Explain aquatic ecosystem with its types.
Answer: A water-based ecosystem is called an aquatic ecosystem. Aquatic ecosystems occupy more than 70% of the earth’s surface. They include marshes, swamps, ponds, lakes, rivers, estuaries, and oceans. These ecosystems play a dominant role in the cycling of chemical substances and are capable of affecting the terrestrial ecosystems. In aquatic ecosystems, the determining factors are penetration of sunlight in water, salinity, waves, currents, and nutrient levels.
Aquatic ecosystems are subdivided into two categories: marine ecosystem and freshwater ecosystem. Marine ecosystem is found in the open oceans, and freshwater ecosystem is found in the inland water bodies like rivers and lakes.
Freshwater ecosystems are lakes, ponds, rivers, streams, and wetlands that have a low salt concentration (usually below 1%) and serve as habitats. Freshwater habitats can be classified by different factors including temperature, light penetration, and vegetation. Freshwater ecosystems can also be classified as lotic and lentic ecosystems. The lotic ecosystems include the flowing water of rivers and streams, and the lentic ecosystems include the still waterbodies like lakes, ponds, swamps, and marshes.
The marine ecosystem is the ecosystem of seas and oceans. It is characterized by high salt content in the water and is the largest habitat on the earth. Depth of ocean water is the greatest factor for the change in species of organisms. Broadly, the oceanic habitat can be divided into three parts: neritic, pelagic, and benthic. The neritic zone is the open water of the continental shelf, which is a shallow water zone and receives maximum sunlight. The pelagic ecosystem extends in the open seas and not on the continental shelf, where abundant sunshine helps in the growth of plankton. The benthic ecosystem refers to anything (biological and non-living) that is associated with the bottom of a body of water. Deeper parts of the ocean make the benthic habitat, which extends from the continental slope and beyond or just below the pelagic habitat. The deepest sea floor is also its part.
Long Answer Questions
1. Define ecosystem. Classify ecosystem in different categories.
Answer: Ecosystem is a self-sufficient unit of biosphere. The term ecosystem refers to the area in which communities interact with each other as well as with their surrounding environment. Ecosystem is classified into Natural ecosystem and Artificial ecosystem. Natural ecosystems are those ecosystems which are under the control of the nature. These ecosystems are further classified into sub-categories. Natural ecosystems are classified into two parts: Terrestrial Ecosystem and Aquatic Ecosystem. Terrestrial ecosystem refers to the ecosystem of land. Aquatic ecosystem is a water-based ecosystem. Artificial ecosystems are man-made ecosystems. These include crop fields, artificial lakes and ponds, aquariums, water bodies etc.
Terrestrial ecosystems are classified as forests, grasslands and deserts. A forest is a naturally growing plant community of trees and other woody vegetation that occupies a large area. Grasslands refer to the land where grass, sedge and forage plants are the main vegetation. A desert is a large area with high evaporation and low precipitation. Aquatic ecosystems include marshes, swamps, ponds, lakes, rivers, estuaries and oceans.
Artificial ecosystems are divided into two categories: land ecosystems and freshwater Ecosystem. Some artificial ecosystems are aquariums, crop fields, greenhouses, nurseries, fish ponds, aquaria, parks or little gardens.
2. Discuss the climatic conditions, flora and fauna in the tropical rainforests.
Answer: Tropical rainforests are found in the equatorial areas of high temperature and heavy rainfall. The average annual temperature remains above 17°C. Such conditions favour the growth of thick and dense evergreen forests. Soils of this area are of poor quality. Rainforests are the most diverse ecosystem on the earth surface. Although they cover only 7% of the earth’s surface yet they contain more than 50% of the plant and animal species. Major trees growing in these forests are kapok, mahogany, rosewood, etc. More than 90% of the animals of these forests are insects and most of them are beetles.
3. Differentiate between the tropical deciduous and temperate deciduous forests.
Answer: Tropical deciduous forests are found in regions where the climate is not very wet. The temperature remains high, and the rainy season alternates with a dry season. On the other hand, temperate deciduous forests are located in areas with mild temperatures and light to moderate rainfall. In tropical deciduous forests, trees shed their leaves during the dry season, making the trees appear lifeless, and the trees are not dense, growing at distances from each other. Common vegetation includes bamboo, teak, and thorny trees. In contrast, temperate deciduous forests shed their leaves during the drought season, typically the winter, and common vegetation includes trees, woody vines, and shrubs.
The type of vegetation in tropical deciduous forests is common in Southeast Asia, Northern Australia, Southern Brazil, and Central America. On the other hand, temperate deciduous forests are home to tree species such as elm, walnut, maple, birch, beech, alder, and chestnut. The important animals found in tropical deciduous forests include buffalo, fox, wild dog, deer, bear, and reptiles like cobra and python. In temperate deciduous forests, popular animals include antelope, boars, turkey hens, stone partridges, black grouse, hyenas, and squirrels.
4. Describe the climate, soil, flora and fauna in the grasslands.
Answer: Grasslands refer to the land where grass, sedge, and forage plants are the main vegetation. Grasslands are natural, semi-natural, or cultivated. The grasslands occupy large continental areas. All grasslands receive low to moderate rainfall. Temperate grasslands grow in the areas characterised by 25 to 75 cm of average annual rainfall, moderate to high temperature, high rate of evaporation, and seasonal droughts. The tropical grasslands are characterised by wet and dry conditions accompanied by very high temperatures.
Semi-natural grasslands, also called successional grasslands, are found in areas where moisture is sufficient to support the growth of trees. They are the result of deforestation activities like burning, cutting, grazing, mowing, etc., and may return to forests in the absence of deforestation activities. Some grasslands are cultivated like hayfields and pastures. They are artificially planted and maintained.
Soils of all grasslands are very fertile. Little rainfall cannot wash away the soil nutrients. Humus content is high. Therefore, many grasslands have been converted into farming lands. Grasslands support a large number of grazing herbivores and carnivores like bison, zebra, tiger, gazelles, giraffes, leopard, deer, hawks, snakes, etc.
The important grasslands are the Prairies of North America, Pampas of South America, Velds of South Africa, Steppes of Eurasia, and Downs of Australia.
5. How are plants able to survive in the deserts?
Answer: Plant life of deserts is well-adapted to dry conditions and daytime heat. These plants consume water efficiently. Woody plants have deep roots and are able to absorb water from depth. These plants normally have small leaves which reduces the surface area for minimum transpiration. Some plants also drop their leaves during the dry season. Thorns are a type of leaves which protect the plants from grazing animals.
6. Write short notes on the following: (i) swamps (ii) marshes
Answer: (i) Swamps : Swamps are wet or flooded areas which are dominated by trees and shrubs. The soil in swamps varies in mineral and nutrients. Swamps are common in the quiet waters of lakes. Some of the common swamps are hardwood forests of lower Mississippi river and Okefenokee swamp in North America. In India, Konalar near Kodaikanal is a large swamp.
(ii) Marshes : Marshes are the flooded areas that are characterized by non-woody plants like grasses, rushes, reeds, typhas, sedges, and other herbaceous plants. The plants are adapted to saturated soils and shallow water. Soil of marshy areas is often rich in minerals. Some of the major marshes of the world are: Everglades of South Florida, Prairie potholes in central North America and coastal areas of Great Lakes at several places in North America. Rann of Kutch is a large marshy area, situated in India and Pakistan. It is a famous breeding ground for flamingoes, pelicans, cranes and storks.
7. Classify the lake ecosystem into various life zones.
Answer: A lake is a depression of land, filled with water. It is much bigger and deeper than a pond. The main producers are plants and algae and the major consumers are fish, turtles, frogs, snails, and worms. Unlike ponds or marshes or swamps, the sunlight cannot reach the bottom of the lake.
8. Estuary is a diverse ecosystem. Explain.
Answer: An estuary is formed where fresh water from the river and salt water from the sea merge. Estuaries remain full of producers, consumers and the decomposers i.e., various species of sea-weeds, algae and other plants (producers). Main consumers are zooplanktons, small crustaceans, tadpole, tortoises and various small fish species. The sea birds in this act as the main or top consumers. Species of bacteria, fungi and the insects act as the decomposers in this ecosystem. Fish, crab and shrimp are common animals found in this zone. Other animals are ducks, geese and herons. Very often, marine animals move into this zone and freshwater animals move out into seas. High productivity is the main feature of this zone. People living around this area catch a large number of fish. In plants, the variety ranges from microscopic phytoplankton to rainforests. Phytoplankton is single-celled algae and a group of algae is called diatom.
9. What are coastal ecosystems?
Answer: Coastal ecosystem is placed between terrestrial ecosystem on land and neritic ecosystem in ocean. It is the shallow zone where land meets water. This zone is alternately submerged and exposed due to daily occurrence of tides. The organisms of this zone are, therefore, subjected to great deal of variation. Waves add to the battering of these organisms. Common coastal or littoral organisms are green algae, fungus, lichens, snails, crabs, sea anemones, small fish, etc.
10. Explain the interaction between biotic and abiotic components.
Answer: Interaction is a term in which two things whether living or non-living interact with each other and must have an effect on each other. In our ecosystem, abiotic and biotic components are linked in such a way that both of them have a direct or indirect effect on each other. Interaction may be of transfer of nutrients and energy from one level (trophic level) to other level. A green plant is a biotic component of the ecosystem. It grows in the soil, takes carbon dioxide from the atmosphere. Here, both soil and carbon dioxide (air) are the abiotic components. This is the interaction. Without this interaction, the processes of the environment may not work properly or may be get stopped. All the biotic components of an ecosystem get affected by wind, climate, rain, weather, etc (abiotic components). In the similar way the abiotic components are affected by the biotic components. We call it as “interaction between the biotic and abiotic components”. Both biotic as well as abiotic components play equally important role for an ecosystem to function properly. Not only are they important but also depend on each other. Their interaction is the key to ecosystem functioning. Moreover, the bodies of all the biotic components are made of elements that are derived from the abiotic components. For example, carbon, oxygen, nitrogen and hydrogen form the amino acids which further lead to the formation of proteins. When organisms or biotic components die, their bodies are decomposed by the decomposers and all these abiotic elements are released back to the environment.
Extras
Additional questions and answers
1. What is an ecosystem?
Answer: Ecosystem is a self-sufficient unit of biosphere. The term ecosystem refers to the area in which communities interact with each other as well as with their surrounding environment.
Q. What are the two main components of an ecosystem?
Answer: Ecosystem is mainly made-up of two components: Biotic – means living and Abiotic means non-living.
Q. Define biotic components.
Answer: Biotic components are the living things that shape the ecosystem. They are any living component that affect another organism. For example, it includes the animals that consume any living component as well as the food material that is consumed by the animal.
Q. Define abiotic components.
Answer: Air, soil, water and several other elements and compounds of the environment are called abiotic components or non-living components. All these non-living substances enter the body of living organisms and take part in the metabolic activities and finally return to the environment.
Q. What is the biosphere?
Answer: Biosphere is relatively a thin zone of land, air and water that is capable of supporting life. It extends from a height of 10 km in the atmosphere to the deepest floor of ocean.
Q. What are the three main spheres of the Earth?
Answer: Lithosphere, atmosphere and hydrosphere.
Q. What is meant by the term “environment”?
Answer: Environment is the surrounding of a living organism. Every living organism whether it is a plant, insect, animal or a man all live in their own surroundings and have their own environment.
Q. Define trophic level.
Answer: Trophic level is nutritional levels in a ecosystem like producers, consumers and decomposers.
Q. What is the primary source of energy in all ecosystems?
Answer: Sunlight is the primary source of energy in all the ecosystems.
Q. Name two gases that plants use from the atmosphere.
Answer: Oxygen and carbon dioxide.
Q. What are the three categories of biotic components?
Answer: The three categories of biotic components are producers, consumers, and decomposers.
Q. Define producers in an ecosystem.
Answer: Producers include green plants, algae, bacteria, grasses, mosses, and all photosynthetic organisms. They convert solar energy into chemical energy with the help of inorganic substances like water and carbon dioxide and organic substances like enzymes.
Q. What is another term for producers?
Answer: Producers are also called autotrophic components.
Q. What pigment is present in producers that helps in photosynthesis?
Answer: Producers possess green pigment called chlorophyll which is present in the leaves and help in preparing their food.
Q. Define consumers.
Answer: Consumers cannot make their own food and so are called consumers. They consume the matter produced by the primary components or producers.
Q. What are heterotrophic organisms?
Answer: Heterotrophic organisms are those that depend on others for nourishment.
Q. What are herbivores also known as?
Answer: Herbivores are also known as primary consumers.
Q. Define carnivores.
Answer: Carnivores are secondary consumers that eat flesh.
Q. What is the role of decomposers in an ecosystem?
Answer: Decomposers depend upon the dead animals for their food. They breakdown the complex organic matter like cellulose and chitin which are found in the plant and animal bodies.
Q. Name two examples of decomposers.
Answer: Two examples of decomposers are bacteria and fungi.
Q. Define interaction in an ecosystem.
Answer: Interaction is a term in which two things whether living or non-living interact with each other and must have an effect on each other.
Q. What are the main abiotic components of an ecosystem?
Answer: The main abiotic components of an ecosystem include air, water, wind, soil, temperature, rainfall, sunlight, and humidity.
Q. How does wind affect an ecosystem?
Answer: Winds carry water vapours which may condense and fall in the form of rain, snow or hail. Wind plays a key role in pollination and seed dispersal of some plants as well as the dispersal of some animals such as insects.
Q. What is the role of temperature in an ecosystem?
Answer: Temperature variation greatly influences the growth of every organism. Among plants, the processes of germination, flowering, falling of leaves etc., are dependent on temperature. Animals are greatly affected by the temperature. Some animals go in hibernation during winters. Some animals migrate to warmer places during winters.
Q. Define humidity.
Answer: Presence of water vapours in the air is called humidity.
Q. What is the role of rainfall in an ecosystem?
Answer: Rainfall is essential for life and all organisms depend on it to survive. It is the basic necessity for the organisms. Aquatic plants and animals cannot survive without water. Water moves in the form of a cycle through evaporation, precipitation and runoff and hence water is available in every ecosystem.
Q. What is the importance of air in an ecosystem?
Answer: Air is an important constituent of the environment. It includes gases like nitrogen, oxygen, carbon dioxide, etc. besides water vapours. All these gases are consumed by the plants and animals. Oxygen is used by all living organisms during respiration. Carbon dioxide is used by green plants during photosynthesis. Nitrogen is made available to plants by certain bacteria and through the action of lightning.
Q. What are the two major types of ecosystems?
Answer: The two major types of ecosystems are Natural ecosystem and Artificial ecosystem.
Q. Define a natural ecosystem.
Answer: Natural ecosystems are those ecosystems which are under the control of the nature.
Q. Define an artificial ecosystem.
Answer: Artificial ecosystems are man-made ecosystems.
Q. What are the two subcategories of natural ecosystems?
Answer: The two subcategories of natural ecosystems are Terrestrial Ecosystem and Aquatic Ecosystem.
Q. Define a terrestrial ecosystem.
Answer: Terrestrial ecosystem refers to the ecosystem of land.
Q. What is an aquatic ecosystem?
Answer: A water based ecosystem is called aquatic ecosystem.
Q. What are the three main terrestrial ecosystems?
Answer: The three main terrestrial ecosystems are Forests, Grasslands, and Deserts.
Q. Define forest ecosystem.
Answer: Forest is a natural growing plant community of trees and other woody vegetation which occupies a large area.
Q. What are the four major types of forests?
Answer: The four major types of forests are Tropical rainforests, Temperate and subtropical evergreen forests, Temperate deciduous forests, and Tropical deciduous forests.
Q. What are tropical rainforests?
Answer: Tropical Rainforests are found in the equatorial areas of high temperature and heavy rainfall.
Q. What are temperate evergreen forests also known as?
Answer: Temperate and Subtropical Evergreen Forests are also known as temperate rain forests.
Q. What is the main characteristic of temperate deciduous forests?
Answer: They shed their leaves during the drought season, i.e., winter season in most of the cases.
Q. Define tropical deciduous forests.
Answer: They are also known as tropical monsoon forests. Climate of this area is not very wet. Temperature remains high and the rainy season alternates with dry season. Trees shed their leaves during dry season and trees appear as lifeless. Trees are not dense and they grow at distance from each other. Bamboo, teak and thorny trees grow in these areas.
Q. What is the importance of forests?
Answer: Maintain and regulate weather conditions. Protect erosion of soil. Control floods. Provide many products like timber, medicines, fruits, gums, resins, dyes and many other products. Also provide home for many animals.
Q. What is a grassland ecosystem?
Answer: The grasslands refer to the land where grass, sedge and forage plants are the main vegetation.
Q. Name two important grasslands of the world.
Answer: Prairies of North America, Pampas of South America.
Q. What is a desert ecosystem?
Answer: Desert is a large area with high evaporation and low precipitation.
Q. What is the average annual rainfall in a desert ecosystem?
Answer: Normally, the average annual rainfall is less than 25 cm.
Q. Define xerophytes.
Answer: Plants that grow under such conditions are called xerophytes.
Q. What is the major adaptation of desert plants?
Answer: Plant life of deserts is well-adapted to dry conditions and daytime heat. These plants consume water efficiently. Woody plants have deep roots and are able to absorb water from depth. These plants normally have small leaves which reduces the surface area for minimum transpiration. Some plants also drop their leaves during dry season.
Q. Name one example of a desert in China.
Answer: Gobi desert of China.
Q. Define freshwater ecosystem.
Answer: Lakes, ponds, rivers, streams and wetlands that have a low salt concentration (usually below 1%) and serve as habitats are called freshwater ecosystems.
Q. What are lentic ecosystems?
Answer: The lentic ecosystems include the still waterbodies like lakes, ponds, swamps, marshes, etc.
Q. What are lotic ecosystems?
Answer: The lotic ecosystems include the flowing water of rivers and streams.
Q. What are marshes?
Answer: Marshes are the flooded areas that are characterized by non-woody plants like grasses, rushes, reeds, typhas, sedges, and other herbaceous plants.
Q. What are swamps?
Answer: Swamps are wet or flooded areas which are dominated by trees and shrubs.
Q. Define a lake ecosystem.
Answer: A lake is a depression of land, filled with water. It is much bigger and deeper than a pond. It is generally fed by a river and in most cases it has natural outflow in the form of a stream. Most of lakes are formed naturally but there are some man-made lakes also. Unlike ponds or marshes or swamps, the sunlight cannot reach the bottom of lake. The main producers are plants and algae and the major consumers are fish, turtles, frogs, snails and worms.
Q. What is a marine ecosystem?
Answer: Ecosystem of seas and oceans is called the marine ecosystem. It is characterized with high salt content in the water. It is the largest habitat on the earth. Depth of ocean water is the greatest factor for the change in species of organisms.
Q. Name the three zones of a marine ecosystem.
Answer: Broadly the oceanic habitat can be divided into three parts: neritic, pelagic and benthic.
Q. Define a coastal ecosystem.
Answer: Coastal ecosystem is placed between terrestrial ecosystem on land and neritic ecosystem in ocean. It is the shallow zone where land meets water. This zone is alternately submerged and exposed due to daily occurrence of tides. The organisms of this zone are, therefore, subjected to great deal of variation. Waves add to the battering of these organisms. Common coastal or littoral organisms are green algae, fungus, lichens, snails, crabs, sea anemones, small fish, etc.
Q. Define an estuary.
Answer: An estuary is formed where fresh water from the river and salt water from the sea merge.
Q. What is a benthic ecosystem?
Answer: The term “benthic ecosystem” refers to anything (biological and non-living) that is associated with the bottom of a body of water. Deeper parts of ocean make benthic habitat. It extends from continental slope and beyond or just below the pelagic habitat. Deepest sea floor is also its part.
Q. What is the function of a phytoplankton?
Answer: Phytoplankton is single-celled algae and a group of algae is called diatom.
Q. What is an artificial ecosystem?
Answer: Artificial ecosystems are man-made ecosystems.
Q. Give one example of an artificial land ecosystem.
Answer: Park or little garden is a man-made ecosystem in our backyards and is the best example for man-made terrestrial ecosystem.
Q. What is an aquarium?
Answer: An aquarium is defined as a container such as a glass tank or an artificial pond in which living aquatic animals or small plants are kept. It represents a small aquatic ecosystem.
Q. What is a greenhouse used for?
Answer: A greenhouse is a man-made ecosystem predominantly containing plants as its constituents.
Q. Define a park ecosystem.
Answer: A park or little garden is a man-made ecosystem in our backyards and is the best example for man-made terrestrial ecosystem. It predominantly contains plants as its constituents and also hosts birds, rodents, and other small species.
Q. What is a biome?
Answer: A biome is a life zone consisting of plants, animals, microorganisms, and their physical environment.
Q. What is the structural and functional unit of the biosphere?
Answer: The structural and functional unit of the biosphere is the ecosystem.
Q. Define lotic ecosystem.
Answer: Lotic ecosystem includes the flowing water of rivers and streams.
Q. Define lentic ecosystem.
Answer: Lentic ecosystem includes the still water bodies like lakes, ponds, swamps, marshes, etc.
Q. What is the role of soil in an ecosystem?
Answer: Soil is the mixture of minerals and organic constituents. All terrestrial plants are supported by soil. Roots of plants absorb water and minerals from the soil. Besides plants, soil also supports insects, bacteria, and fungi which help in the decomposition of organic matter.
Q. What is a habitat?
Answer: Habitat is placed between terrestrial ecosystem on land and neritic ecosystem in ocean. It is the shallow zone where land meets water.
Q. What are the biotic components of an ecosystem? Describe each component in detail.
Answer: Biotic components are the living things that shape the ecosystem. They are any living component that affects another organism. There are three biotic components: producers, consumers, and decomposers.
(a) Producers: These include green plants, algae, bacteria, grasses, mosses, and all photosynthetic organisms. They are also called autotrophic components. They convert solar energy into chemical energy with the help of inorganic substances like water and carbon dioxide and organic substances like enzymes. They are called autotrophic because ‘auto’ means ‘self’ and ‘trophic’ means ‘nourishing’. They possess green pigment called chlorophyll which is present in the leaves and helps in preparing their food.
(b) Consumers: These cannot make their own food and so are called consumers. They consume the matter produced by the primary components or producers. They are also called heterotrophic because ‘hetero’ means ‘others’ and ‘trophic’ means ‘nourishing’. They may be microorganisms like zooplankton, insects, and animals like cow, deer, tiger, elephant, etc. Some animals eat plants and are called herbivores or primary consumers, and some eat flesh and are called carnivores or secondary consumers.
(c) Decomposers: These depend upon the dead animals for their food. They are the microorganisms like bacteria, fungi, etc. They break down the complex organic matter like cellulose and chitin which are found in the plant and animal bodies.
Q. Define abiotic components of an ecosystem and explain the role of each in maintaining ecological balance.
Answer: Abiotic components are non-living components like air, soil, water, wind, temperature, rainfall, and sunlight. Air is an important constituent of the environment and includes gases like nitrogen, oxygen, carbon dioxide, etc., besides water vapours. Oxygen is used by all living organisms during respiration. Carbon dioxide is used by green plants during photosynthesis. Nitrogen is made available to plants by certain bacteria and through the action of lightning. Soil is the mixture of minerals and organic constituents. All terrestrial plants are supported by soil. Roots of plants absorb water and minerals from the soil. Besides plants, soil also supports insects, bacteria, and fungi which help in the decomposition of organic matter. Water is essential for life and all organisms depend on it to survive. It moves in the form of a cycle through evaporation, precipitation, and runoff and hence is available in every ecosystem. Sunlight is the primary source of energy in all ecosystems and is used by green plants which contain chlorophyll during the process of photosynthesis. Temperature variation greatly influences the growth of every organism. Humidity is the presence of water vapours in the air and is required by many insects and microorganisms. Wind carries water vapours which may condense and fall in the form of rain, snow, or hail and plays a key role in pollination and seed dispersal.
Q. Discuss the interaction between biotic and abiotic components within an ecosystem, providing specific examples.
Answer: Interaction is a term in which two things whether living or non-living interact with each other and must have an effect on each other. In our ecosystem, abiotic and biotic components are linked in such a way that both of them have a direct or indirect effect on each other. Interaction may be of transfer of nutrients and energy from one level (trophic level) to another level. A green plant is a biotic component of the ecosystem. It grows in the soil, takes carbon dioxide from the atmosphere. Here, both soil and carbon dioxide (air) are the abiotic components. This is the interaction. Without this interaction, the processes of the environment may not work properly or may get stopped. All the biotic components of an ecosystem get affected by wind, climate, rain, weather, etc (abiotic components). In the similar way, the abiotic components are affected by the biotic components. Both biotic as well as abiotic components play equally important roles for an ecosystem to function properly. Not only are they important but also depend on each other. Their interaction is the key to ecosystem functioning. The bodies of all the biotic components are made of elements that are derived from the abiotic components. For example, carbon, oxygen, nitrogen, and hydrogen form the amino acids which further lead to the formation of proteins. When organisms or biotic components die, their bodies are decomposed by the decomposers and all these abiotic elements are released back to the environment.
Q. Describe the various types of terrestrial ecosystems, including their defining features and examples.
Answer: Terrestrial ecosystems are classified as forests, grasslands, and deserts.
- Forests: Forest is a natural growing plant community of trees and other woody vegetation which occupies a large area. In its natural state, a forest remains generally fixed in a self-regulated condition over a long period of time. The factors of a forest are its climate, soil, and topography. Since vegetation also affects the soil, the relationship is reciprocal between physical environment and the life forms. Major forest types are Tropical rainforests, Temperate and subtropical evergreen forests, Temperate deciduous forests, and Tropical deciduous forests.
- Grasslands: The grasslands refer to the land where grass, sedge, and forage plants are the main vegetation. Features of Grasslands are: Grasslands are natural, semi-natural, or cultivated. The grasslands occupy large continental areas. The important grasslands are Prairies of North America, Pampas of South America, Velds of South Africa, Steppes of Eurasia, and Downs of Australia. All grasslands receive low to moderate rainfall. Temperate grasslands grow in the areas characterized by 25 to 75 cm of average annual rainfall, moderate to high temperature, high rate of evaporation, and seasonal droughts. The tropical grasslands are characterized by wet and dry conditions accompanied by very high temperature. Semi-natural grasslands also called successional grasslands are found in the areas where moisture is sufficient to support the growth of trees.
- Deserts: Desert is a large area with high evaporation and low precipitation. Features of Desert are: Normally, the average annual rainfall is less than 25 cm. Most of the deserts are situated on the Tropic of Cancer and Tropic of Capricorn. Temperature remains high in the Tropical deserts and severe winters are peculiar of temperate deserts. Important deserts of northern hemisphere are Sahara desert of Africa, Gobi desert of China, California desert of North America, Arabian and Iranian desert of the Middle East. The deserts of southern hemisphere are Patagonia desert of Argentina, Atacama desert of Chile, Kalahari desert of South Africa, Namib desert of SW Africa, and Great Victoria and Great Sandy desert of Australia. Desert ecosystem is made up of grasses, thorny bushes. Plants that grow under such conditions are called xerophytes. Some plants are Acacia, zizipus, cacti, asparagus, etc.
Q. Explain the different types of aquatic ecosystems.
Answer: Aquatic ecosystems are subdivided into two categories: marine ecosystem and freshwater ecosystem. Marine ecosystem is found in the open oceans and freshwater ecosystem is found in the inland water bodies like rivers and lakes. Freshwater ecosystems include marshes, swamps, ponds, lakes, rivers, estuaries, and coastal areas. Marshes are flooded areas characterized by non-woody plants like grasses, rushes, reeds, typhas, sedges, and other herbaceous plants. Swamps are wet or flooded areas dominated by trees and shrubs. Lakes are depressions of land filled with water, much bigger and deeper than ponds. Marine ecosystems are characterized by high salt content in the water and are the largest habitat on earth. The oceanic habitat can be divided into three parts: neritic, pelagic, and benthic. Neritic ecosystems are in the open water of the continental shelf, pelagic ecosystems extend into the open seas, and benthic ecosystems are associated with the bottom of a body of water.
Q. What are the major types of forests? Provide detailed descriptions of each type.
Answer: Major forest types are tropical rainforests, temperate and subtropical evergreen forests, temperate deciduous forests, and tropical deciduous forests. Tropical rainforests are found in equatorial areas of high temperature and heavy rainfall. The average annual temperature remains above 17°C, favoring the growth of thick and dense evergreen forests. Soils of this area are of poor quality, but rainforests are the most diverse ecosystems on earth, containing more than 50% of plant and animal species. Temperate and subtropical evergreen forests grow in areas of mild temperature and heavy rainfall in middle latitudes. They remain evergreen throughout the year due to heavy rainfall, and sunlight easily penetrates the canopy, leading to well-developed ground vegetation. Temperate deciduous forests are found in areas of mild temperature and light to moderate rainfall. Trees shed their leaves during the drought season, and common species include elm, walnut, maple, birch, beech, alder, chestnut, and ashes. Tropical deciduous forests, also known as tropical monsoon forests, have climates that are not very wet, with high temperatures and alternating rainy and dry seasons. Trees shed their leaves during the dry season and are not dense, growing at distances from each other.
Q. Discuss the climatic conditions, flora, and fauna characteristic of tropical rainforests.
Answer: Tropical rainforests are found in equatorial areas of high temperature and heavy rainfall. The average annual temperature remains above 17°C. Such conditions favor the growth of thick and dense evergreen forests. Soils of this area are of poor quality. Rainforests are the most diverse ecosystems on the earth’s surface, containing more than 50% of plant and animal species, though they cover only 7% of the earth’s surface. Major trees growing in these forests are kapok, mahogany, rosewood, etc. More than 90% of the animals in these forests are insects, and most of them are beetles.
Q. Describe the features of temperate and subtropical evergreen forests.
Answer: Temperate and subtropical evergreen forests grow in areas of mild temperature and heavy rainfall in middle latitudes. Heavy rainfall makes them evergreen throughout the year. Sunlight can easily penetrate the canopy of these trees, so ground vegetation is well-developed in the form of epiphytes. They are widespread in the western parts of North America and the eastern parts of Asia. Animals that inhabit these forests are puma, jaguar, bear, etc.
Q. Explain the characteristics of temperate deciduous forests.
Answer: Temperate deciduous forests are found in areas of mild temperature and light to moderate rainfall. They shed their leaves during the drought season, i.e., winter season in most cases. Trees, woody vines, and shrubs are common vegetation of these forests. Important species of trees are elm, walnut, maple, birch, beech, alder, chestnut, and ashes. Popular animals inhabiting these forests are antelope, boars, turkey hens, stone partridges, black grouse, hyenas, and squirrels.
Q. Define tropical deciduous forests and discuss their unique features.
Answer: Tropical Deciduous Forests are also known as tropical monsoon forests. Features of Tropical Deciduous Forests are: Climate of this area is not very wet. Temperature remains high and the rainy season alternates with dry season. Trees shed their leaves during dry season and trees appear as lifeless. Trees are not dense and they grow at distance from each other. Bamboo, teak and thorny trees grow in these areas. This type of vegetation is common in the Southeast Asia, Northern Australia, Southern Brazil and Central America. Important animals of this area are buffalo, fox, wild dog, deer, bear, etc. Among reptiles, cobra and python are common.
Q. Define grasslands and describe their main features.
Answer: The grasslands refer to the land where grass, sedge and forage plants are the main vegetation. Features of Grasslands are: Grasslands are natural, semi-natural or cultivated. The grasslands occupy large continental areas. The important grasslands are Prairies of North America, Pampas of South America, Velds of South Africa, Steppes of Eurasia and Downs of Australia. All grasslands receive low to moderate rainfall. Temperate grasslands grow in the areas characterized by 25 to 75 cm of average annual rainfall, moderate to high temperature, high rate of evaporation and seasonal droughts. The tropical grasslands are characterised by wet and dry conditions accompanied with very high temperature. Semi-natural grasslands also called successional grasslands are found in the areas where the moisture is sufficient to support the growth of trees. They are the result of deforestation activities like burning, cutting, grazing, mowing, etc, and may return to forests in the absence of deforestation activities. Some grasslands are cultivated like hayfields and pastures. They are artificially planted and maintained. Soils of all grasslands are very fertile. Little rainfall cannot wash away the soil nutrients. Humus content is high. Therefore, many grasslands have been converted into farming lands. Grassland support large number of grazing herbivores and carnivores like bison, zebra, tiger, gazelles, giraffes, leopard, deer, hawks, snakes etc.
Q. Discuss the characteristics of temperate grasslands.
Answer: Temperate grasslands grow in the areas characterized by 25 to 75 cm of average annual rainfall, moderate to high temperature, high rate of evaporation and seasonal droughts. Soils of all grasslands are very fertile. Little rainfall cannot wash away the soil nutrients. Humus content is high. Therefore, many grasslands have been converted into farming lands. Grassland support large number of grazing herbivores and carnivores like bison, zebra, tiger, gazelles, giraffes, leopard, deer, hawks, snakes etc.
Q. Explain the features of tropical grasslands.
Answer: The tropical grasslands are characterised by wet and dry conditions accompanied with very high temperature. Grass, sedge and forage plants are the main vegetation. Grassland support large number of grazing herbivores and carnivores like bison, zebra, tiger, gazelles, giraffes, leopard, deer, hawks, snakes etc.
Q. Describe the defining characteristics of desert ecosystems.
Answer: Desert is a large area with high evaporation and low precipitation. Features of Desert are: Normally, the average annual rainfall is less than 25 cm. Most of the deserts are situated on the Tropic of Cancer and Tropic of Capricorn. Temperature remains high in the Tropical deserts and severe winters are peculiar of temperate deserts. Important deserts of northern hemisphere are: Sahara desert of Africa, Gobi desert of China, California desert of North America, Arabian and Iranian desert of the Middle East. The deserts of southern hemisphere are Patagonia desert of Argentina, Atacama desert of Chile, Kalahari desert of South Africa, Namib desert of SW Africa and Great Victoria and Great Sandy desert of Australia. Desert ecosystem made-up of grasses, thorny bushes. Plants that grow under such conditions are called xerophytes. Some plants are: Acacia, zizipus, cacti, asparagus etc. Characteristics of Plants in Deserts are: Plant life of deserts is well-adapted to dry conditions and daytime heat. These plants consume water efficiently. Woody plants have deep roots and are able to absorb water from depth. These plants normally have small leaves which reduces the surface area for minimum transpiration. Some plants also drop their leaves during dry season. Thorns are a type of leaves which protect the plants from grazing animals. Rat, rabbits, goats, sheep, camels and many other animals are found in the deserts. Snakes, lizards are also found here.
Q. Discuss the adaptations of plants and animals that enable them to survive in desert conditions.
Answer: Plant life of deserts is well-adapted to dry conditions and daytime heat. These plants consume water efficiently. Woody plants have deep roots and are able to absorb water from depth. These plants normally have small leaves which reduces the surface area for minimum transpiration. Some plants also drop their leaves during dry season. Thorns are a type of leaves which protect the plants from grazing animals. Rat, rabbits, goats, sheep, camels and many other animals are found in the deserts. Snakes, lizards are also found here.
Q. Explain the characteristics of marine ecosystems.
Answer: Ecosystem of seas and oceans is called the marine ecosystem. It is characterized with high salt content in the water. It is the largest habitat on the earth. Depth of ocean water is the greatest factor for the change in species of organisms. Broadly the oceanic habitat can be divided into three parts: neritic, pelagic and benthic. Neritic zone is the open water of the continental shelf. It is a shallow water zone and receives maximum sunlight. Pelagic ecosystem extends in the open seas and not on the continental shelf. Abundant sunshine helps in the growth of plankton. The term “benthic ecosystem” refers to anything (biological and non-living) that is associated with the bottom of a body of water. Deeper parts of ocean make benthic habitat. It extends from continental slope and beyond or just below the pelagic habitat. Deepest sea floor is also its part.
Q. Discuss the features of coastal ecosystems.
Answer: Coastal ecosystem is placed between terrestrial ecosystem on land and neritic ecosystem in ocean. It is the shallow zone where land meets water. This zone is alternately submerged and exposed due to daily occurrence of tides. The organisms of this zone are, therefore, subjected to great deal of variation. Waves add to the battering of these organisms. Common coastal or littoral organisms are green algae, fungus, lichens, snails, crabs, sea anemones, small fish, etc.
Q. Define estuaries and explain their ecological significance.
Answer: An estuary is formed where fresh water from the river and salt water from the sea merge. Estuaries remain full of producers, consumers and the decomposers i.e., various species of sea-weeds, algae and other plants (producers). Main consumers are zooplanktons, small crustaceans, tadpole, tortoises and various small fish species. The sea birds in this act as the main or top consumers. Species of bacteria, fungi and the insects act as the decomposers in this ecosystem. Fish, crab and shrimp are common animals found in this zone. Other animals are ducks, geese and herons. Very often, marine animals move into this zone and freshwater animals move out into seas. High productivity is the main feature of this zone. People living around this area catch a large number of fish.
Q. What are artificial ecosystems? Provide examples and discuss their characteristics?
Answer: Artificial ecosystems are man-made ecosystems. These include crop fields, artificial lakes and ponds, aquariums, water bodies etc. Mainly these are divided into two categories: Land Ecosystem and Freshwater Ecosystem. Some artificial ecosystems are Crop fields, Green houses, Nurseries, Fish ponds, and Aquaria.
Q. Describe the features of crop fields as artificial ecosystems?
Answer: Crop fields are a type of artificial ecosystem. They are predominantly managed by humans and consist of cultivated plants which serve as producers. The components of crop fields include crops that are grown for food, fiber, or other products. Their function is to provide resources necessary for human consumption and economic activities.
Q. Explain the characteristics of artificial aquatic ecosystems?
Answer: Artificial aquatic ecosystems like fish ponds and aquaria are man-made water-based systems designed to mimic natural aquatic environments. Fish ponds are used for rearing fish and other aquatic organisms for food production. Aquaria are containers such as glass tanks or artificial ponds in which living aquatic animals or small plants are kept. They represent a small aquatic ecosystem. Their ecological roles include supporting biodiversity, providing habitats for aquatic life, and serving educational purposes.
Q. Discuss the role of forests in maintaining and regulating weather conditions, preventing soil erosion, and controlling floods.
Answer: Forests maintain and regulate weather conditions. They protect erosion of soil, control floods, provide many products like timber, medicines, fruits, gums, resins, dyes and many other products. Also, they provide home for many animals.
Q. Explain how grasslands support large numbers of grazing herbivores and carnivores, and their importance in agriculture.
Answer: Grasslands support large numbers of grazing herbivores and carnivores like bison, zebra, tiger, gazelles, giraffes, leopard, deer, hawks, snakes etc. Soils of all grasslands are very fertile. Little rainfall cannot wash away the soil nutrients. Humus content is high. Therefore, many grasslands have been converted into farming lands.
Q. Describe the significance of desert ecosystems in terms of biodiversity and their unique adaptations to extreme conditions.
Answer: Desert ecosystems are significant in terms of biodiversity. Plants that grow under such conditions are called xerophytes. Some plants are Acacia, zizipus, cacti, asparagus etc. Characteristics of Plants in Deserts include being well-adapted to dry conditions and daytime heat. These plants consume water efficiently. Woody plants have deep roots and are able to absorb water from depth. These plants normally have small leaves which reduce the surface area for minimum transpiration. Some plants also drop their leaves during dry season. Thorns are a type of leaves which protect the plants from grazing animals. Animals found in deserts include rats, rabbits, goats, sheep, camels and many others. Snakes and lizards are also found here.
Q. Discuss the importance of aquatic ecosystems in nutrient cycling and their influence on terrestrial ecosystems.
Answer: Aquatic ecosystems play a dominant role in the cycling of chemical substances and are capable of affecting the terrestrial ecosystems. In aquatic ecosystems, the determining factors are penetration of sunlight in water, salinity, waves, currents and nutrient levels.
99. Define freshwater ecosystems and describe their various types.
Answer: Lakes, ponds, rivers, streams and wetlands that have a low salt concentration (usually below 1%) and serve as habitats are called freshwater ecosystems. Freshwater habitats can be classified by different factors including temperature, light penetration and vegetation. A variety of plant and animal life flourishes in the fresh waterbodies. Freshwater ecosystems can also be classified as lotic and lentic ecosystems. The lotic ecosystems include the flowing water of rivers and streams. The lentic ecosystems include the still waterbodies like lakes, ponds, swamps, marshes, etc. Marshes are the flooded areas that are characterized by non-woody plants like grasses, rushes, reeds, typhas, sedges, and other herbaceous plants. Swamps are wet or flooded areas which are dominated by trees and shrubs. A lake is a depression of land, filled with water. It is much bigger and deeper than a pond.
Additional MCQs
1. What is the surrounding of a living organism commonly called?
A. Ecosystem
B. Environment
C. Biosphere
D. Habitat
Answer: B. Environment
2. Which term refers to the area in which communities of organisms interact with each other and their environment?
A. Ecology
B. Biosphere
C. Ecosystem
D. Habitat
Answer: C. Ecosystem
3. Which set correctly represents the two main components of an ecosystem?
A. Producers and decomposers
B. Carnivores and herbivores
C. Biotic and abiotic
D. Water and soil
Answer: C. Biotic and abiotic
4. Which sphere of the Earth is relatively thin and supports life?
A. Lithosphere
B. Biosphere
C. Atmosphere
D. Hydrosphere
Answer: B. Biosphere
5. Which of the following is considered a biotic component in an ecosystem?
A. Soil
B. Wind
C. Decomposer
D. Temperature
Answer: C. Decomposer
6. Which term is given to organisms that cannot make their own food and depend on producers?
A. Autotrophs
B. Abiotics
C. Heterotrophs
D. Ecosystems
Answer: C. Heterotrophs
7. Which group of organisms breaks down complex organic matter from dead plants and animals?
A. Producers
B. Consumers
C. Herbivores
D. Decomposers
Answer: D. Decomposers
8. Which pigment allows green plants to carry out photosynthesis?
A. Carotene
B. Chlorophyll
C. Hemoglobin
D. Anthocyanin
Answer: B. Chlorophyll
9. What do primary consumers (herbivores) mainly feed on?
A. Flesh of other animals
B. Dead and decaying matter
C. Green plants
D. Decomposers
Answer: C. Green plants
10. Which abiotic factor is used by green plants to convert solar energy into chemical energy?
A. Soil
B. Sunlight
C. Wind
D. Temperature
Answer: B. Sunlight
11. Which gas is primarily used by green plants during photosynthesis?
A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Argon
Answer: C. Carbon dioxide
12. Which term describes the tiny pores on the lower side of leaves used for gas exchange?
A. Phloem
B. Chloroplasts
C. Stomata
D. Xylem
Answer: C. Stomata
13. Which important abiotic component provides anchorage and nutrients to terrestrial plants?
A. Humidity
B. Soil
C. Temperature
D. Water
Answer: B. Soil
14. In the context of water bodies, what is the main driving force behind the water cycle (evaporation, precipitation, runoff)?
A. Decomposers
B. Green plants
C. Solar energy
D. Chemicals
Answer: C. Solar energy
15. Which abiotic factor greatly influences germination, flowering, and leaf fall in plants?
A. Temperature
B. Wind
C. Soil type
D. Humidity
Answer: A. Temperature
16. What is the presence of water vapour in the air known as?
A. Fog
B. Vaporization
C. Condensation
D. Humidity
Answer: D. Humidity
17. Which abiotic component helps in pollination and seed dispersal of certain plants by carrying them over distances?
A. Sunlight
B. Soil
C. Wind
D. Temperature
Answer: C. Wind
18. What term describes the effect when living (biotic) and non-living (abiotic) components affect each other?
A. Interaction
B. Photosynthesis
C. Ingestion
D. Metamorphosis
Answer: A. Interaction
19. In an ecosystem, how is energy primarily passed from one trophic level to the next?
A. By decomposition
B. By chemical compounds only
C. Through feeding relationships
D. By respiration alone
Answer: C. Through feeding relationships
20. What is the key reason biotic components depend on abiotic factors like climate and rainfall?
A. For genetic variation
B. For survival and growth
C. For decomposition of matter
D. For color pigmentation only
Answer: B. For survival and growth
21. Which of the following best describes a self-sufficient unit of the biosphere?
A. Trophic level
B. Population
C. Community
D. Ecosystem
Answer: D. Ecosystem
22. Which of these components returns elements like carbon and nitrogen to the environment by breaking down dead organisms?
A. Consumers
B. Decomposers
C. Producers
D. Parasites
Answer: B. Decomposers
23. Which type of ecosystem exists under nature’s control and is not created by humans?
A. Artificial ecosystem
B. Natural ecosystem
C. Industrial ecosystem
D. Non-renewable ecosystem
Answer: B. Natural ecosystem
24. Which of the following is a natural terrestrial ecosystem?
A. Aquarium
B. Cropland
C. Grassland
D. Fish pond
Answer: C. Grassland
25. Which of the following is a natural aquatic ecosystem?
A. Park
B. Artificial pond
C. Aquarium
D. Lake
Answer: D. Lake
26. Which type of ecosystem is maintained or created by human activities?
A. Grassland
B. Artificial ecosystem
C. Desert
D. Tropical rainforest
Answer: B. Artificial ecosystem
27. Which of the following is an example of an artificial terrestrial ecosystem?
A. Marshland
B. Park
C. River
D. Swamp
Answer: B. Park
28. Which of the following is an example of an artificial aquatic ecosystem?
A. River
B. Ocean
C. Aquarium
D. Lake
Answer: C. Aquarium
29. Which major category of ecosystem includes forests, grasslands, and deserts?
A. Terrestrial
B. Marine
C. Freshwater
D. Artificial
Answer: A. Terrestrial
30. Which type of forest is found in equatorial areas with high temperature and heavy rainfall?
A. Temperate deciduous
B. Tropical rainforest
C. Temperate evergreen
D. Tropical monsoon
Answer: B. Tropical rainforest
31. Which forest type is also known as the temperate rainforest?
A. Tropical rainforest
B. Grassland forest
C. Subtropical evergreen forest
D. Desert forest
Answer: C. Subtropical evergreen forest
32. Which feature is common in temperate evergreen forests?
A. Very sparse ground vegetation
B. Leaves that change color every month
C. Heavy rainfall making them evergreen
D. Extremely cold winters with no rainfall
Answer: C. Heavy rainfall making them evergreen
33. Which type of forest is found in areas of mild temperature and light to moderate rainfall, where trees shed leaves in the winter?
A. Tropical deciduous forest
B. Subtropical evergreen forest
C. Temperate deciduous forest
D. Tropical rainforest
Answer: C. Temperate deciduous forest
34. Which forest is also known as the tropical monsoon forest?
A. Tropical deciduous forest
B. Temperate evergreen forest
C. Tropical rainforest
D. Temperate deciduous forest
Answer: A. Tropical deciduous forest
35. Which term is used for land covered mainly with grasses, sedges, and forbs as dominant vegetation?
A. Coastal
B. Grassland
C. Desert
D. Forest
Answer: B. Grassland
36. What is the average annual rainfall range in temperate grasslands?
A. 10–15. cm
B. 25–75. cm
C. 90–120. cm
D. 150–200. cm
Answer: B. 25–75. cm
37. Which of the following is a key characteristic of soils in grasslands?
A. Very poor in nutrients
B. High in humus content
C. Always waterlogged
D. No organic matter
Answer: B. High in humus content
38. Which biome is characterized by high evaporation and low precipitation, typically less than 25. cm annually?
A. Desert
B. Grassland
C. Marsh
D. Temperate forest
Answer: A. Desert
39. Most of the world’s deserts are found near which latitudes?
A. Near the poles
B. At the equator
C. Along the Tropic of Cancer and Tropic of Capricorn
D. Only in the Northern Hemisphere
Answer: C. Along the Tropic of Cancer and Tropic of Capricorn
40. Which plant adaptation is common in deserts to reduce transpiration?
A. Broad leaves
B. Bright flowers
C. Small or needle-like leaves
D. Thick bark only
Answer: C. Small or needle-like leaves
41. Which desert is located in northwest China and was once a fertile region with Buddhist civilization?
A. Sahara
B. Taklimakan
C. Atacama
D. Kalahari
Answer: B. Taklimakan
42. Which organism is often found in deserts and is adapted to minimal water availability?
A. Dolphin
B. Camel
C. Python
D. Penguin
Answer: B. Camel
43. Which term refers to water-based ecosystems occupying more than 70% of Earth’s surface?
A. Marine ecosystem
B. Terrestrial ecosystem
C. Artificial ecosystem
D. Aquatic ecosystem
Answer: D. Aquatic ecosystem
44. Which factor is most crucial in determining species variation in marine ecosystems?
A. Temperature of the land nearby
B. Depth of ocean water
C. Shape of the coastline
D. Salinity of the soil
Answer: B. Depth of ocean water
45. Which of the following is a freshwater ecosystem?
A. Oceanic zone
B. Coastal reef
C. Marsh
D. Pelagic zone
Answer: C. Marsh
46. What is the dominant vegetation in marshes?
A. Tall trees and shrubs
B. Non-woody plants like grasses and sedges
C. Cacti and thorny bushes
D. No vegetation at all
Answer: B. Non-woody plants like grasses and sedges
47. Which flooded area is characterized by woody plants like trees and shrubs?
A. Marsh
B. Swamp
C. Desert
D. Benthic zone
Answer: B. Swamp
48. Which large marshy area is situated between India and Pakistan, known for its flamingo breeding grounds?
A. Pampas
B. Rann of Kutch
C. Prairies
D. Downs
Answer: B. Rann of Kutch
49. Which freshwater body is larger and deeper than a pond, often fed by a river?
A. Swamp
B. Lake
C. Marsh
D. Stream
Answer: B. Lake
50. Why can sunlight generally not reach the bottom of most lakes?
A. The sediment layer is too thick
B. The water is too salty
C. The depth is too great
D. The temperature is too high
Answer: C. The depth is too great
51. Which group of organisms typically forms the main producers in a lake ecosystem?
A. Zooplankton
B. Algae and plants
C. Snakes and lizards
D. Decomposers
Answer: B. Algae and plants
52. Which type of ecosystem is characterized by high salt content and includes seas and oceans?
A. Grassland ecosystem
B. Artificial ecosystem
C. Marine ecosystem
D. Desert ecosystem
Answer: C. Marine ecosystem
53. Which marine zone refers to the shallow water of the continental shelf that receives maximum sunlight?
A. Pelagic zone
B. Benthic zone
C. Neritic zone
D. Abyssal zone
Answer: C. Neritic zone
54. Which zone extends in the open seas beyond the continental shelf and is rich in plankton?
A. Neritic zone
B. Pelagic zone
C. Benthic zone
D. Coastal zone
Answer: B. Pelagic zone
55. Which term describes the bottom zone of an ocean, extending from the continental slope to the deepest sea floor?
A. Pelagic zone
B. Neritic zone
C. Coastal zone
D. Benthic zone
Answer: D. Benthic zone
56. Which ecosystem lies between the terrestrial ecosystem on land and the neritic ecosystem in the ocean?
A. Desert
B. Coastal
C. Grassland
D. Tropical rainforest
Answer: B. Coastal
57. Why is the coastal zone (intertidal zone) exposed and submerged alternately?
A. High winds
B. Wave currents
C. Tides
D. Earthquakes
Answer: C. Tides
58. Which organisms are common in the coastal or littoral zone?
A. Desert foxes
B. Polar bears
C. Lichens and snails
D. Rainforest tigers
Answer: C. Lichens and snails
59. What forms where fresh water from a river meets salt water from the sea in one channel?
A. Delta
B. Mangrove
C. Estuary
D. Coastal reef
Answer: C. Estuary
60. Which factor makes estuaries highly productive ecosystems?
A. Extreme dryness
B. High tidal activity and nutrient mix
C. No decomposition
D. Cold, freezing waters
Answer: B. High tidal activity and nutrient mix
61. Which of the following organisms are often top consumers in estuaries?
A. Sea birds
B. Earthworms
C. Tiger sharks
D. Tree frogs
Answer: A. Sea birds
62. In estuaries, which small organisms are primary producers alongside seaweeds?
A. Corals
B. Zooplankton
C. Phytoplankton
D. Crabs
Answer: C. Phytoplankton
63. Which is an example of a man-made aquatic ecosystem?
A. Natural swamp
B. River delta
C. Fish pond
D. Estuary
Answer: C. Fish pond
64. Which man-made structure is often kept in homes or offices to observe small aquatic organisms?
A. Well
B. Aquarium
C. Marsh
D. Bog
Answer: B. Aquarium
65. Which man-made terrestrial ecosystem includes small plant communities and sometimes ornamental shrubs?
A. Forest
B. Greenhouse
C. Desert
D. Mountain
Answer: B. Greenhouse
66. Why are crop fields considered artificial ecosystems?
A. They are untouched by humans
B. They are sustained naturally without care
C. They require human intervention and management
D. They do not have food chains
Answer: C. They require human intervention and management
67. In an aquarium, which organism typically acts as a decomposer?
A. Algae
B. Aquarium plants
C. Bacteria
D. Fish
Answer: C. Bacteria
68. What is the role of forests in controlling floods?
A. By consuming excess water with roots
B. By preventing rainfall
C. By increasing temperature
D. By causing droughts
Answer: A. By consuming excess water with roots
69. Which type of forest is known for its thick canopy that sunlight can barely penetrate?
A. Tropical rainforest
B. Grassland forest
C. Temperate deciduous forest
D. Desert forest
Answer: A. Tropical rainforest
70. Which biome is the next level of ecological organization above an ecosystem, having distinct climate and life forms?
A. Population
B. Biome
C. Community
D. Biosphere
Answer: B. Biome
71. Which of the following best describes a biome characterized by extremely low precipitation and sparse vegetation?
A. Temperate rainforest
B. Desert
C. Grassland
D. Tropical monsoon forest
Answer: B. Desert
72. Why do desert plants often have thorns instead of broad leaves?
A. To conserve water
B. To produce more flowers
C. For absorbing carbon dioxide faster
D. To attract herbivores
Answer: A. To conserve water
73. In which aquatic ecosystem zone do sea anemones, small fish, and crabs commonly thrive, exposed to tides?
A. Pelagic
B. Coastal or littoral
C. Benthic
D. Neritic
Answer: B. Coastal or littoral
74. What is the primary source of energy for almost all ecosystems on Earth?
A. Fossil fuels
B. Tidal currents
C. Sunlight
D. Earth’s core heat
Answer: C. Sunlight
75. How do bacteria and fungi help return nutrients to the environment after organisms die?
A. By causing erosion of rocks
B. By creating permanent waste
C. By decomposing organic matter
D. By absorbing all minerals without release
Answer: C. By decomposing organic matter
