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Correct OPTION is (c) Seral stage

To ELABORATE: A seral community is alternatively KNOWN as a seral stage. Seral communities are the individual transitional communities of a sere that develop in that AREA during the SUCCESSION.

Correct choice is (C) Some species grow while other species DECLINE

The explanation: Ecological succession is the GRADUAL change in the species COMPOSITION of a given area which can be PREDICTED. During an ecological succession, some species colonize and grow while other species decline or disappear.

The correct choice is (d) Seral COMMUNITIES

The best explanation: The communities in a given area having SUCCESSIVELY changing SEQUENCES are known as a SERE. Seral communities are the individual transitional communities of a sere that develop in that area during the SUCCESSION.

Correct option is (b) Sere

The explanation is: The COMMUNITIES in a given AREA having successively changing sequences are known as a sere. A sere is an intermediate or a halfway STAGE occurring during ecological succession in an environment PROGRESSING towards its climax COMMUNITY.

Correct option is (d) Ecological succession

To explain I would say: A series of CHANGES take place in biotic communities during their NATURAL development. The changes in the community are CONSTANT, dynamic, orderly and SEQUENTIAL. Ecological succession is the gradual change in the species composition of a given area which can be predicted.

Right choice is (B) COMPOSITION and structure constantly changes

For explanation: CONSTANT change in composition and structure due to change in environmental conditions is a characteristic of all communities. A group of populations is known as a community. It is a group of PEOPLE who share the same PLACE or live within the same area.

Correct ANSWER is (b) Climax community

The BEST I can explain: The CHANGES in the community are constant, orderly and sequential. The changes in a community that is in NEAR equilibrium with the environment lead to the FORMATION of a climax community.

The CORRECT OPTION is (a) Orderly and SEQUENTIAL

For explanation: The CHANGES in the community are constant, orderly and sequential. These changes are usually parallel with the changes occurring in a physical ENVIRONMENT surrounding the community.

Correct choice is (B) Consumers

To explain I would SAY: The consumers are present in the maximum NUMBER in a pond ECOSYSTEM. The pyramid of energy and number is upright while the pyramid of biomass is INVERTED in a pond ecosystem.

The correct option is (c) First

Easiest EXPLANATION: Though the pyramid of energy is ALWAYS upright, the energy content decreases at SUCCESSIVE trophic levels from producers to consumers. The producers gain the first POSITION in the pyramid of energy because they have maximum energy.

Correct answer is (d) Lion

For EXPLANATION I would say: If plants, grasshopper, birds, and lion are the components of an ECOSYSTEM, the least number is OBTAINED by a lion. This is because, the lion being the top-most consumer in an ecosystem, it GETS the least amount of food and energy since these things are lost at every level.

Correct choice is (B) SECOND

Explanation: The TOTAL dry weight of the total amount of living MATTER at each level (from producers to consumers) is represented by the pyramid of biomass. The HERBIVORES obtain the second position if the pyramid of biomass is upright.

The correct CHOICE is (c) Energy content

To explain: Though the pyramid of energy is always UPRIGHT, the energy content DECREASES at successive trophic levels from producers to CONSUMERS. At each level, some amount of energy is lost into the surroundings in the form of heat.

Right choice is (d) ENERGY

The BEST explanation: If an ecosystem is stable, the pyramid of energy is upright. The pyramid of energy is SAID to be the best representation of an ecosystem because it indicates the rate of energy flow through the FOOD chain.

Correct choice is (b) Individuals in a trophic level

To explain: The PYRAMID of numbers represents the NUMBER of individuals at each level (producers forming the base and top CARNIVORES forming the tip). Depending upon the nature of the food chain, the pyramid is inverted or UPRIGHT.

Correct choice is (c) THREE types

Explanation: There are three types of ecological PYRAMIDS. They are the pyramid of energy (UPRIGHT), the pyramid of NUMBER (inverted or upright) and the pyramid of BIOMASS (inverted or upright).

Correct ANSWER is (d) The rate of energy flow through the food chain

The EXPLANATION: The pyramid of energy is said to be the BEST representation of an ecosystem because it indicates the rate of energy flow through the food chain. DEPENDING upon the nature of the food chain, the pyramid is always UPRIGHT.

The correct choice is (b) The relationship among the organisms

Easiest EXPLANATION: The relationship among the organisms is REPRESENTED by the pyramid of number and pyramid of biomass. The pyramid of number represents the number of individuals at each level while the total DRY weight of the total AMOUNT of living matter at each level is represented by the pyramid of biomass.

Correct choice is (a) PYRAMID of biomass

To explain: The idea of productivity of an ECOSYSTEM is BASED on the pyramid of biomass. The total dry weight of the total AMOUNT of LIVING matter at each level (from producers to consumers) is represented by the pyramid of biomass.

Correct choice is (B) Pyramid of number

For explanation I would SAY: The relationship of prey being more than PREDATORS is represented by the pyramid of numbers. It represents the number of INDIVIDUALS at each level (producers forming the base and top carnivores forming the TIP).

The CORRECT choice is (b) Upright

Best EXPLANATION: In a forest ECOSYSTEM the PYRAMID of the number depicted is always upright. The pyramid of NUMBERS represents the number of individuals at every level.

Right ANSWER is (a) Pyramid of BIOMASS

The best explanation: The total amount of LIVING material (biomass) in a food chain is depicted using the pyramid of biomass. The pyramid of biomass for an ocean scheme is INVERTED. This is OFTEN as a result of the biomass of fishes is quite that of phytoplankton.

Correct option is (C) PYRAMID of biomass

Explanation: Depending upon the nature of the food chain, the pyramid of biomass is inverted or upright. The TOTAL dry weight of the total amount of living MATTER at each level (from producers to CONSUMERS) is represented by the pyramid of biomass.

Correct answer is (b) Pyramid of number

To elaborate: The pyramid of the number is inverted or upright, depending upon the nature of the food CHAIN (organic and inorganic MATTER). The pyramid of the number represents the number of individuals at every level (PRODUCERS forming the bottom and high CARNIVORES forming the tip).

Right answer is (c) Pyramid of ENERGY

The best EXPLANATION: The pyramid of energy is ALWAYS upright, depending upon the nature of the food CHAIN. The pyramid of energy usually represents the rate of FLOW of energy or productivity at the successive level.

Correct option is (c) Pyramid of biomass

Easiest explanation: The TOTAL dry weight of the total amount of LIVING MATTER at each level (from producers to consumers) is represented by the pyramid of biomass. Depending upon the nature of the FOOD chain, the pyramid is inverted or upright.

The correct option is (d) PYRAMID of energy

To elaborate: The rate of FLOW of energy or productivity at successive LEVEL (from producers to consumers) is REPRESENTED by the pyramid of energy. Depending upon the nature of the food chain, the pyramid is ALWAYS upright.

Correct OPTION is (d) Pyramid of numbers

Easiest explanation: The pyramid of numbers REPRESENTS the number of INDIVIDUALS at each level (producers forming the base and top CARNIVORES forming the tip). Depending UPON the nature of the food chain, the pyramid is inverted or upright.

Correct choice is (B) ELTONIAN pyramids

Easiest explanation: A graphical representation of the relationship between the individuals present in VARIOUS trophic levels of a food CHAIN is called an ecological pyramid. Ecological pyramids are ALTERNATIVELY called Eltonian pyramids. The ecological pyramids were formulated by Charles Elton in 1927.

The CORRECT choice is (d) Energy

Easy explanation: The relationship between PRODUCERS and consumers at each trophic level is represented on the basis of energy or productivity at each trophic level. It can also be represented on the basis of the NUMBER of INDIVIDUALS and biomass at each level.

Right option is (b) Biomass

For explanation I would SAY: The relationship between producers and consumers at each TROPHIC level is represented on the basis of biomass or the total dry weight of living MATTER. It can also be represented on the basis of the number of individuals and the energy at each level.

The correct answer is (c) CHARLES Elton

Explanation: In 1927, Charles Elton formulated ecological pyramids. A GRAPHICAL illustration of the LINK (PRODUCERS forming the bottom and top carnivores forming the tip) between the individuals present in various trophic levels of a food chain is CALLED an ecological pyramid.

The correct answer is (a) Number

To elaborate: The relationship between producers and CONSUMERS (at each TROPHIC level) is depicted BASED on the number of INDIVIDUALS. This relationship can also be depicted based on energy and biomass content at every level.

The correct OPTION is (b) Phytoplankton → Zooplankton → FISHES → Fungi

For explanation I WOULD say: A food chain FOUND in any aquatic body is known as an aquatic food chain. In this phytoplankton is the producer, zooplankton is the herbivore, FISH is the carnivore, and fungi are the decomposers.

Right answer is (b) ECOLOGICAL pyramid

Explanation: A graphical illustration of the relationship (producers forming the bottom and TOP carnivores forming the tip) between the individuals present in various trophic levels of a food CHAIN is called an ecological pyramid. In 1927, Charles Elton FORMULATED ecological pyramids.

The correct choice is (c) Grass → Deer → Wolf → FUNGI

The explanation is: A food chain FOUND in the grassland area is KNOWN as a grassland food chain. In this grass is the producer, deer is the HERBIVORE, a wolf is a carnivore, and fungi are the DECOMPOSERS.

Right CHOICE is (d) Decomposers

The BEST explanation: PRODUCERS (primary consumers) are organisms that make their own food with the help of energy obtained from chemicals or the sun, WATER, and air. Their population is highest in an ECOSYSTEM.

Correct option is (c) Mineralization will not occur

The best I can explain: If decomposers are REMOVED from the ECOSYSTEM, the process of mineralization will stop. The process of release of inorganic substances both MINERALS (H2O, CO2, etc.) and non-minerals from organic MATTER (e.g. Ca^2+, NH4, Mg^2+, K^+, etc.) is CALLED mineralization. It is the last step in the process of decomposition.

Correct OPTION is (d) Tertiary consumer

Explanation: The organisms that cannot manufacture their own food and obtain ready-made ORGANIC food from producers are CALLED consumers. MAN belongs to the tertiary consumer level.

Right choice is (B) Heterotrophs

To elaborate: Decomposers are heterotrophs. The organisms that are RESPONSIBLE for the break down complex organic MATTER (dead or DECAYING organisms) into inorganic substances are called decomposers (detritivores).

Right choice is (c) CATTLE and zooplankton

The best I can explain: Plants and phytoplankton belong to the category of primary consumers. Producers (primary consumers) are organisms that make their own FOOD with the help of energy obtained from CHEMICALS or the sun, WATER, and air. They are also known as autotrophs.

Right answer is (a) Four

To EXPLAIN I would say: In general a food chain CONSISTS of 3-4 trophic levels. Plants consists represent the first level, herbivores are in second. The CARNIVORES and top carnivores COME under the third and fourth trophic levels respectively.

Correct ANSWER is (b) Trophic levels

Explanation: The food levels in an ecosystem are alternatively called trophic levels. The step or division that ORGANISMS OCCUPY in a food chain that is characterized by the METHOD of obtaining their nutrition to fulfill their energy requirements is known as a trophic level.

Correct choice is (a) Unidirectional movement of energy

Best explanation: In an ecosystem, a unidirectional FLOW of energy occurs. The movement of energy from the higher trophic levels and its distribution and loss as heat to the lower trophic levels in the environment is unidirectional. It MEANS the energy moves in one DIRECTION only that is from higher to the lower-most LEVEL.

The correct choice is (d) Solar energy

For EXPLANATION I WOULD SAY: Solar energy is said to be the driving force of an ECOSYSTEM. The solar energy is converted into USABLE form by plants with the help of photosynthesis.

Right choice is (b) Consumer

For explanation: The RATE of production of NEW ORGANIC matter by heterotrophic organisms (consumers) is CALLED secondary productivity. The secondary producers feed on PRIMARY consumers to fulfill their energy requirements.