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.
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
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
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