Q3 Ecology 2Mar
ECOLOGY
Qts1. 'Ecology' is the study of the relationship between-
(a) Organism and environment
(b) Man and forest
(c) Soil and water
(d) Husband and wife
Ans. (a)
The word 'ecology' originated from Greek 'Oikos' meaning house or environment. Ecology is the study of interactions among organisms and their environment. It also includes the study of organismal interaction with abiotic components of their environment. The word 'ecology' ('Oekologie') was coined by German scientist, Ernst Haeckel (1834-1919). Haeckel defined Ecology as the study of the relationship of an organism with their environment. Ecology in current age refers to a broader spectrum encompassing not only plants, animal species and climate but also to human beings and it's physical surroundings.
Qts2. Which of the following is not correct about the ecosystem?
(a) It comprises both, abiotic and biotic components
(b) It has its productivity.
(c) It is a closed system.
(d) It is a natural resource system.
Ans. (c)
An ecosystem is a community of living organisms in conjunction with the non-living components of their environment (things like air, water and mineral soil), interacting as a system.
Important features of ecology are:
- It is normally an open system with a continuous, but variable influx and loss of materials and energy.
- An ecosystem is an overall integration of the whole mosaic of the interacting organism and their environment.
- It is a basic functional unit with no limits of boundaries.
- It consists of biotic and abiotic components interacting with each other.
- Its functional unit is capable of energy transformation, circulation and accumulation.
- Different types of the ecosystem are present in different areas.
Qts3.The number of organisms that can be supported by the environment in a given area is known as:
(a) Population
(b) Carrying Capacity
(c) Pyramid of number or biomass
(d) None of the above
Ans. (b)
The maximum population size that can ecosystem can support is called capacity carrying capacity is the number of organism that an ecosystem can sustainably support. Hence option (b) is correct
Qts4. Which one of the following terms describes not only the physical space occupied by an organism but also its functional role in the community of organisms?
(a) Ecotone
(b) Ecological niche
(c) Habitat
(d) Home range
Ans. (b)
Ecological niche characterizes the position of a species within an ecosystem, comprising species habitat requirements as well as its functional role
Qts5. The actual location or place where an organism lives is called:
(a) Habitat
(b) Ecosystem
(c) Niche
(d) Biome
(e) None of the above/More than one of the above
Ans. (a)
The location or place where an organism lives is called a habitat. The organisms depend for their food, water, air, shelter and other needs on their habitat. A biome is a plant and animal community that covers a large geographical area Some of the major biomes of the world are: forest, grassland, desert and tundra biomes.
Qts6. Which one of the following ecosystems covers the largest area of the earth's surface:
(a) Desert Ecosystem
(b) Grassland Ecosystem
(c) Mountain Ecosystem
(d) Marine Ecosystem
Ans
There are mainly two kinds of ecosystems Aquatic and Terrestrial.1 Marine ecosystems are the biggest ecosystems. which cover around 71% of Earth's surface and contain 97% of our planes Water Thus option (d) is the correct answer
Qts7. Which one of the following is the largest ecosystem of the world?
(a) Ocean
(b) Grassland
(c) Forest
(d) Mountains
Ans. (a)
Aquatic ecosystem refers to living and non-living parts of a water body and the interactions that take place among them Aquatic ecosystems can be categorized in the marine ecosystem and freshwater ecosystem, Marine ecosystem covers approximately 71% of the earth's surface and contains approximately 97% of the planet's water
Qts8. Which of the following does not help to maintain ecological balance?
(a) Cutting forest
(b) Afforestation
(c) Rainwater Management
(d) Biosphere Reserves
Ans. (a)
Wildlife conservation and prevention of environmental pollution is helpful in maintaining ecological balance. Deforestation adds to the environmental imbalance
Qts9. Which one of the following is one of the main causes of ecological imbalance in India?
(a) Deforestation
(b) Desertification
(c) Floods and Famines
(d) Rainfall variations
Ans. (a)
Deforestation is one of the main causes of ecological imbalance in India While, desertification, floods and famines and rainfall variations are secondary causes
Qts10. Which of the following is an act that disturbs the ecological balance?
(a) Lumbering
(b) Social forestry
(c) Vanamahotsav
(d) Afforestation
Ans: (a)
It is lumbering which disturbs the ecological balance
Qts11.The highest tropile tevet in an ecosystem is obtained bys
(a) Herbivores
(b) Carnivores
(c) Omnivores
(d) Decomposers
Ans. (c)
There are four types of trophic levels in the food chain of the ecosystem They are-
- First trophic level-Producer
- Second trophic level- Primary consumers (herbivorous)
- Third trophic level-Secondary consumers (carnivorous)
- Fourth trophic level- Tertiary consumers (omnivorous)
- Decomposers feed on all the above trophic levels.
Qts12. Which of the following is not a biotic component of an ecosystem?
(a) Air
(b) Plant
(c) Bacteria
(d) Animals
Ans. (a)
Biotic components are the living things that shape an ecosystem
Biotic components usually include
Producers: eg plants.
Consumers eg. animals, humans
Decomposers eg fungi and bacteria
Qts13. The primary source of energy in Eco-body is -
(a) Energy emitted by fermentation
(b) Preserved vegetable sugar
(c) Solar energy
(d) None of the above
Ans. (c)
Solar energy is the primary source of energy in the ecological body. It is the driving force of an ecosystem
Qts14. Driving force of an ecosystem is:
(a) Carbohydrate
(b) Biomass
(c) Carbon
(d) Solar energy
Ans. (d)
Solar energy is the primary source of energy in the ecological body. It is the driving force of an ecosystem
Qts15. Concerning the food chains in ecosystems, which of the following kinds of an organism is/are known as decomposer organism/organisms?
1. Virus
2. Fungi
3. Bacteria
Select the correct answer using the code given below:
(a) Only 1
(b) 2 and 3
(c) 1 and 3
(d) All of these
Ans. (b)
Decomposers are nature's recyclers as they break down the organic matter found in the dead bodies of plants and animals. The term 'organic matter' refers to the matter that comes from living organisms. Decomposers are mainly the microorganisms such as bacteria and fungi in the form of yeasts and moulds that break down bodies of dead organisms and release compounds that can be used by producers.
Qts16. Which of the following are the primary consumers in an ecosystem? Select the correct answer from the codes given below:
1. Ants
2. Deer
3. Fox
4. Tiger
Code:
(a) 1 and 2
(b) 2 and 3
(c) 1, 2 and 3
(d) 2, 3 and 4
Ans. (a)
Mainly herbivores, in a food chain, are considered as primary consumers. In the given options, Deer is herbivorous hence it is a primary consumer. Ants fall under decomposer and primary consumers both. It eats plants and receives energy from cellulose. Tiger is carnivorous and the fox is omnivorous Significantly, primary consumers feed on primary producers plants) Hence option (a) is the correct answer
Qts17. In a food chain, man is:
(a) producer
(b) only primary consumer
(c) only secondary consumer
(d) primary as well as a secondary consumer
Ans. (d)
In food chain there are trophic levels i.e., Autotroph, Primary consumer, Secondary consumer and Tertiary consumer. The primary consumer is the herbivores (that feed on the plant), the secondary consumer is small carnivores (feeding on primary consumer) and the tertiary consumer is larger carnivores. So, in food chain, man is the primary as well as a secondary consumer who feeds on both plant, products and meat.
Qts18. In the marine environment, the main primary producers are:
(a) Phytoplanktons
(b) Seaweeds
(c) Marine angiosperms
(d) Aquatic bryophytes
Ans. (a)
Phytoplankton, also known as microalgae, are similar to terrestrial plants in that they contain chlorophyll and require sunlight to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean, where sunlight penetrates the water. Phytoplankton also requires inorganic nutrients such as nitrates, phosphates, and sulfur which they convert into proteins, fats, and carbohydrates.
Qts19. Among the biotic components of the ecosystem, the producer system is
(a) Cow
(b) Peacock
(c) Tiger
(d) Green Plants
Ans. (d)
Plants are self-feeding organisms that produce complex organic compounds such as carbohydrates, fats and proteins generally using energy from light (photosynthesis). These are known as autotrophs and are fundamental to the food chain of all ecosystems. These are called primary producers.
Qts20. What is true about ecosystem?
(a) Primary consumers are least dependent upon producer
(b) Primary consumers are out-number producers
(c) Producers are more than primary consumers
(d) Secondary consumers are the largest and most powerful
Ans. (c)
In a given ecosystem, there are generally more producers than primary consumers, and more primary consumers than secondary consumers, and so on.
Qts21. Which one of the following pairs is correctly matched?
(a) Mountain- Most stable ecosystem
(b) Abiotic Component-Bacteria
(c) Green plants-Ecosystem
(d) Rainfall-Global Warming
Ans. (c)
All the pairs mentioned in the question are related to ecosystems but correctly matched is only (c). An ecosystem is a community of living organisms in conjunction with the non-living components of their environment. Since plants are living organism hence they are related to the ecosystem.
Qts22. The correct order in the food chain of the various components of a terrestrial grass ecosystem is
(a) Grass, Grasshopper, Frog, Snake
(b) Grass, Grasshopper, Snake, Frog
(c) Grasshopper, Frog, Grass, Snake
(d) Grasshopper, Snake, Frog, Grass
Ans. (a)
Any substance consumed to provide nutritional support for an organism is called food Plants are self-feeding and make for their own food whereas animals depend on plants for food Food chain depicts the flow of energy through different organisms in an ecosystem Notably, this flow is unidirectional. The correct order of different components in the above food chain is as follows:
Grass-Grasshopper-Frog-Snake
Qts23. Which of the following constitute a food chain?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat
(e) None of the above
Ans. (b)
Grass, goat and humans form a food chain
Qts24. The pyramid of energy in any ecosystem is
(a) Always upright
(b) May be upright and inverted
(c) Always inverted
(d) None of the above
Ans. (a)
Pyramid of energy is always upright, can never be inverted, because when energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step. Each bar in the energy pyramid indicates the amount of energy present at each trophic level in a given tone or annually per unit area Hence option (a) is correct
Qts25. Biomass Pyramid is reversed in which type of ecosystem?
(a) Forest
(b) Pond
(c) Grassland
(d) Drylands
Ans. (b)
The Pyramid of Biomass is a graphical representation that depicts the extent of biomass per unit area within different trophic levels in an ecological system. In grasslands and forests, there is a gradual decrease in the biomass of organisms at successive levels from the producers to the top carnivores. Thus, pyramids are upright. However, in a pond, as the producers are small organisms, their biomass is least and this value gradually shows an increase towards the apex of the pyramid, thus making the pyramid inverted in shape.
Qts26. Which one of the following organisms is likely to show the highest concentration of DDT, once it has been introduced into the ecosystem?
(a) Grasshopper
(c) Snake
(b) Toad
(d) Cattle
Ans. (c)
DDT is a non-biodegradable, biomagnifying pollutant which increases in concentration from producers, primary consumers, secondary consumers to tertiary consumers. In the question, only the snake represents the tertiary consumers, so the concentration of DDT will be highest in the snake.
Qts27. The amount of energy during the transfer from one trophic level to another in an eco-system-
(a) Increases
(b) Decreases
(c) Remains constant
(d) May increase or decrease
Ans. (b)
Energy is the basic force responsible for all metabolic activities. The flow of energy from producer to top consumers is called energy flow, which is unidirectional. Energy flows through the trophic levels i.e. from producers to subsequent trophic levels. This energy always flows from lower (producer) to higher (herbivore, carnivore, etc.) trophic level. There is a loss of some energy in the form of unusable heat at each trophic level so the amount of energy during the transfer from one trophic level to another decreases in an ecosystem.
Qts28. The amount of energy during transfer from one trophic level to another in an ecosystem-
(a) Increases
(b) Decreases
(c) Remains constant
(d) May increase or decrease
Ans. (b)
Energy is the basic force responsible for all metabolic activities. The flow of energy from producer to top consumers is called energy flow, which is unidirectional. Energy flows through the trophic levels i.e. from producers to subsequent trophic levels. This energy always flows from lower (producer) to higher (herbivore, carnivore, etc.) trophic level. There is a loss of some energy in the form of unusable heat at each trophic level so the amount of energy during the transfer from one trophic level to another decreases in an ecosystem.
Qts29. Which one of the following trees is not eco-friendly?
(a) Babul
(b) Eucalyptus
(c) Neem
(d) Pipal
Ans. (b)
Eucalyptus consumes more ground water than other trees. That is why it often called 'enemy of the environment'. The water level goes down across the area of Eucalyptus plantation. These plants are mostly found in Australia.
Qts30. Which one of the following trees is considered to be am environmental hazard?
(a) Babul
(b) Amaltas
(c) Neem
(d) Eucalyptus
Ans. (d)
Eucalyptus consumes more ground water than other trees. That is why it often called 'enemy of the environment'. The water level goes down across the area of Eucalyptus plantation. These plants are mostly found in Australia.
Qts31. The example of "Lentic Habitat" in the freshwater community is:
(a) Ponds and swamps
(b) Waterfalls and rivers
(c) Ponds and rivers
(d) All the above.
Ans. (a)
Lentic Ecosystem refers to the static water habitats like pond lakes, swamps and marshes. Lotic Ecosystem refers to dynamics water habitats like rivers.
Qts32. The transitional zone between two distinct communities is known as:
(a) Ecotype
(b) Arcade
(c) Ecosphere
(d) Ecotone
Ans. (d)
Ecotone is a region of transition between two biological communities.
Qts33. Which of the following is the most stable ecosystem?
(a) Desert
(b) Mountain
(c) Ocean
(d) Forest
Ans. (c)
Oceans are the cradle of life on Earth which harbor the highest level of biodiversity. No terrestrial ecosystem can match the biological richness of a coral reef, not only in some species but also in variety and originality of survival strategies.
Qts34. Which of the following is an example of anthropogenic biome?
(a) Fresh water
(b) Grassland
(c) Rain forest
(d) Cropland
Ans. (d)
Freshwater, Grassland and Rain for at are examples of natural biome whereas cropland is an example of the anthropogenic biome.
Qts35. Consider the following statements:
1. Most of the world's coral reefs are in tropical waters.
2. More than one-third of the world's coral reefs an located in the territories of Australia, Indones and the Philippines.
3. Coral reefs host far more number of animal phyla than those hosted by tropical rainforests. Which of the statements given above is/are correct?
Ans.
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Ans. (d)
Corals are invertebrate animals. Reefs are created by hard corals which secrete a skeleton that can turn into giant structures like Australia's 'Great Barrier Reef. Most of the world's coral reefs are located in tropical oceans near the equator. More than one-third of the world's coral reef is located in the territories of Australia. Indonesia and Philippines.
Coral reefs are one of the most diverse ecosystems on the planet. These tropical marine communities occupy less than 1% of the ocean floor but are inhabited by more than 25% of all known marine fish species. 32 of the 34 recognized animal phyla are formed on coral reefs compared to 9 phyla in tropical rainforests.
Qts36. Which one of the following is the largest ecosystem of the earth?
(a) Hydrosphere
(b) Biome
(c) Lithosphere
(d) Biosphere
The largest ecosystem of the earth is Biosphere. The biosphere is a part of the earth where life can exist. It is a highly integrated and interacting zone comprising of atmosphere (air) hydrosphere (water) and lithosphere (land). It is a narrow layer around the surface of the earth. The biosphere is absent at extremes of the North and South Poles, the highest mountains and the deepest oceans.
Qts 37. In case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrient to entry the cycle ?
(a)carbon cycle
(b) Nitrogen cycle
(c) Phosphorus cycle
(d) Sulphur cycle
Ans. (c)
Phosphorus is a chemical element found on Earth numerous compound forms, such as the phosphate ion located in water, soil and sediments.
Much of the phosphorus on Earth is tied up in rock and sedimentary deposits, from which it is released by weathering, leaching, and mining.
Some of it passes through freshwater and terrestrial ecosystems via plants, grazers, predators, and parasites, to be returned to those ecosystems by death and decay, Much of it, however, is deposited in the sea, in shallow sediments, where it circulates readily, or in ocean deeps, whence it wells up only occasionally.
Phosphorus is brought back to the land through fish harvests and through collection of guano deposited by seabirds.
Qts38. The movement of nutrient elements through various components of an ecosystem is called:
(a) Bio-geo-chemical cycle
(b) Bio-geological cycle
(c) Ecological succession
(d) Biological cycle
Ans. (a)
Phosphorus is a chemical element found on Earth numerous compound forms, such as the phosphate ion located in water, soil and sediments.
Much of the phosphorus on Earth is tied up in rock and sedimentary deposits, from which it is released by weathering, leaching, and mining.
Some of it passes through freshwater and terrestrial ecosystems via plants, grazers, predators, and parasites, to be returned to those ecosystems by death and decay, Much of it, however, is deposited in the sea, in shallow sediments, where it circulates readily, or in ocean deeps, whence it wells up only occasionally.
Phosphorus is brought back to the land through fish harvests and through collection of guano deposited by seabirds.
Qts39. Which one of the following is not related to ecological balance?
(a) Water management
(b) Afforestation
(c) Industrial Management
(d) Wildlife protection
Ans. (c)
Water management, afforestation and wildlife protection is associated with Ecological balance while industrial management is not associated with ecological balance.
Qts40. Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity?
(a) Oceans, lakes, grasslands, mangroves
(b) Mangroves, oceans, grasslands, lakes
(c) Mangroves, grasslands, lakes, oceans
(d) Oceans, mangroves, lakes, grasslands
Ans. (c)
The correct sequence of the ecosystem in the order of decreasing productivity is- Mangrove, grasslands, lakes, oceans.
Qts41. Concerning food chains in ecosystems, consider the following statements
1. A food chain illustrates the order in which a chain of organisms feeds upon each other.
2. Food chains are found within the population of a species.
3. A food chain illustrates the number of organism, which is eaten by others.
Which of the statements given above is/are correct?
(a) Only 1
(b) 1 and 2
(c) 1, 2 and 3
(d) None of these
Ans. (a)
Now most obvious aspect of nature is that energy must pass from one living organism to another. When herbivorous animals feed on plants, energy is transferred from plants to animals. In an ecosystem, some of the animals feed on other living organisms while some feed on dead organic matter. The latter form the detritus food chain. Each chain usually has only four to five such links. Food chains are not found within the population of a species. Because this would mean a human being eating another human being (human beings are single species)
Qts42. Which of the following statement is correct?
(a) The energy flow in the biospheric ecosystem is unidirectional.
(b) The energy flows in the biospheric is cyclical.
(c) Relative loss of energy in natural ecosystem decrease with increasing trophic levels.
(d) Species at progressively higher trophic levels appear to be less efficient in using available energy
Ans. (a)
The flow of energy in the ecosystem is unidirectional (or one-directional). The energy enters the plants (from the sun) through photosynthesis during the making of food. This energy is then passed on from one organism to another in a food chain. The energy given out by the organisms as heat is lost to the environment. It does not return to be used by the plants again. This makes the flow of energy in the ecosystem 'unidirectional'. According to the first law of thermodynamics, energy can neither be created nor be destroyed in an isolated system. According to the second law whenever energy transforms into a new form, there is evident decay in its intensity. Similarly, with increasing trophic levels availability of energy decreases in the natural ecosystem.