Ecosystem Structure and Food Chains

Most pastures are already under substantial grazing pressure, in effect forcing sheep to steeper and less productive pastures. An important long-term goal is to improve forage conditions for native prey species to help reduce depredation pressures on domestic stock.

Heavy metals and persistent pesticides (e.g., organochlorine of chlorinated hydrocabons like DDT) pass into food chain and increase in amount per unit weight of organisms with the rise in trophic level due to their accumulation in fat, This phenomenon is called biomagnification. Therefore, lower the trophic level of fish (such as small fish), lesser will be the biomagnification and hence safer it will be for consumption.

Mainly climate in tropical regions is hot and humid. It sees rainfall and high temperatures during summers. 

The consumers in an ecosystem are heterotrophs, mostly animals which feed on other organisms. Consumers are also called as phagotrophs, as they ingest food. Consumers can be first order consumers, e.g., herbivores, cattle, rabbit, deer, insects like grasshopper etc. They feed on producers. Primary carnivores are second order consumers. They feed on herbivores. Secondary carnivores are third order consumers which feed on primary carnivores. For example, Small fish and water insects like scavenger beetles that feed on the crustaceans. 

An ecosystem is a segment of nature or biosphere consisting of a community of living beings and the abiotic or physical environment, both interacting and exchanging materials between them. An ecosystem which lacks one or the other component is called as an 'Incomplete ecosystem', e.g., sea bottom and caves where sunlight may not reach and consequently photoautotrophs or green plants may not flourish; freshly formed rain water pond where plants may not have well settled and a pond formed in rains may be temporary also.

Food chain is the sequence of organisms through which food and energy is passed in an ecosystem with the members of trophic level. Trophic level is the hierarchical levels in an ecosystem which consists organism

Trophic levels are steps or divisions of food chain characterised by the specific method of obtaining food. Producers belong to first trophic level, herbivores to second trophic level and carnivores to third trophic level. Bamboo plant, which is a producer will belong to first trophic level. It will capture solar energy for other organisms living in the forest. Thus, the correct answer is option A.

In a pond or lake ecosystem, zooplanktons (ciliates, flagellates, rotifers, small crustaceans, like Cyclops and Daphnia larvae) are directly dependent on phytoplanktons. Thus, the correct answer is option A.

Rat is a herbivore animal, who used to eat plant products. The potato plant is a producer who trap solar energy and produces food (carbohydrates), which are stored in potato tubers. The rat cannot produces their own food by the use of solar energy and hence, feeds on potato tuber for his life processes.

Food chain in an ecosystem is defined as the passage of food from one trophic level to the next higher trophic level. The transfer of food from one trophic level to the next level results in the passage of energy through these trophic levels. A food chain can have 3 or 4 trophic levels. Plants are producers which are present in first trophic level. Primary consumers are second trophic levels which eat plants. They are herbivores. Secondary consumer are present make third trophic level. They eat primary consumers and are carnivores. Tertiary or top consumer make fourth trophic level. They are carnivores

A food chain is series of plants/animals which are interrelated in the form of organism being eaten as food by the other. A food chain consists of producers abd consumers. In the given food chain, plants are producers. They are present in the first trophic level. It is also called as T$ _1$ trophic level. The animals eating plants are called as primary consumers. They are herbivores and occupy the second trophic level in an ecosystem. It is also called as T$ _2$ trophic level. Animals eating primary consumers are called as secondary consumers. They occupy the third trophic level in an ecosystem. It is also called as T$ _3$ trophic level. 

A. Gross primary productivity (GPP) is a term used to describe the rate at which plants and other photosynthetic organisms produce organic compounds in an ecosystem. Hence 'GPP - Photosynthetic organisms' are related to each other.

A fish consuming phytoplanktons occupies primary consumer level while when consuming another small fish, it occupies secondary consumer level. So, a fish can occupy more than one trophic level in a pond ecosystem.

A trophic level is a group of organisms within an ecosystem which occupy the same level in a food chain. There are five main trophic levels within a food chain, each of which differs in its nutritional relationship with the primary energy source. The primary energy source in any ecosystem is the Sun. Primary producers are usually plants and algae, which perform photosynthesis in order to manufacture their own food source. Primary producers make up the first trophic level. The second trophic level consists of herbivores, these organisms gain energy by eating primary producers and are called primary consumers. Trophic levels three, four and five consists of carnivores and omnivores. Trophic level three consists of carnivores and omnivores (Example: Man) which eat herbivores; these are the secondary consumers. 

A man feeding on curd occupied the third trophic level. Here, the grasses are at the first trophic level, the cow/buffalo who feeds on grasses is at the second trophic level. The curd is prepared by the milk of cow/buffalo by the action of bacteria, but the energy of the milk is getting transferred to the man, so man is at the third trophic level.

Food web represents an interconnection of many food chains in an ecosystem and that is the reason in a food web, there can be organisms occupying different trophic level at the same time. For example, in a food web, a crow can be at the second trophic level or at the fourth trophic level.

In a typical forest food chain (e.g., grass -> deer -> lion), the lion acts as the secondary or tertiary consumer. In a standard three-step chain, it is the third trophic level (T3).

A food web represents the complex, non-linear feeding relationships in an ecosystem by showing how multiple food chains overlap and interconnect.

When multiple food chains in an ecosystem overlap or interlock, the resulting structure is called a food web.

The trophic level is the sequential arrangement of several organisms on the basis of the number, energy flow, and biomass present at the different level. Food chains start at trophic level 1 with primary producers, such as plants, move to herbivores at level 2, predators at level 3 and finish with carnivores or apex predators at level 4 or 5. Thus, the correct answer is option D.

Vultures are scavenging birds that feed on dead animals. Vultures do not kill their own prey, they feed on dead animals. As scavengers, vultures play an important role in the ecosystem by decomposing the dead animal matter, cleaning the environment and reducing the spread of diseases.

• Ecosystems are said to be self-regulating or self-sustained in that each contains feedback mechanisms, which function to maintain the components of the system in one or other of its equilibrium states.
• An equilibrium state demonstrates the stability of ecosystems. Even in these stable states, the components of ecosystems are in dynamic exchanges, and these exchanges involve the build-up of energy or materials, which cycle the ecosystem either within a single equilibrium or between various equilibrium states. 
• It is the adaptive capacity of ecosystems, that have provided both the stability and the enormous range of diversity on earth.
• Food chains start at trophic level 1 with primary producers such as plants, moved to herbivores at level 2, predators at level 3 and finish with carnivores or apex predators at level 4 or 5.
  Thus, the correct answer is option D.

Trophic structure of an ecosystem is a type of producer-consumer arrangement, in which each food level is called as trophic level and the graphical representation of the trophic structure of ecosystem constitutes ecological pyramids. The green plants are producers and represent the first trophic level. So, bamboo plant is in the first trophic level.

Fishes occupy more than one trophic level because some feed only on phytoplanktons and zooplankton, while other feeds on algae or other food sources across various strata of the water body  

An omnivore is an organism, that regularly consumes a variety of material, including plants, animals, algae, and fungi. Human beings are omnivores. People eat plants, such as vegetables and fruits. Human beings eat animals, cooked as meat or used for products like milk or eggs. Human eats fungi, such as mushrooms. We also eat algae, in the form of edible seaweeds, such as nori, which are used to wrap sushi rolls, and sea lettuce, eaten in salads. Both omnivores and carnivores, meat eaters, are at the third trophic level. Carnivores and omnivores are secondary consumers.

A food web is a natural interconnection between the food chains. Each living thing in an ecosystem is part of multiple food chains. Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem. All of the interconnected and overlapping food chains in an ecosystem make up a food web.

A food web consists of all the food chains in a single ecosystem. Each living thing in an ecosystem is part of multiple food chains. Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem. All of the interconnected and overlapping food chains in an ecosystem make up a food web.

• The trophic level of an organism is the position it occupies in a food chain. A food chain represents a succession of organisms that eat another organism and are, in turn, eaten by others. 
• Food chains start at trophic level 1 with primary producers such as plants, move to herbivores at level 2, predators at level 3 and finish with carnivores or apex predators at level 4 or 5.

• Herbivores are at the second level of the food chain and mainly eat plants. Herbivores are considered primary consumers and are the first consumers on the food chain. 
• The honey bee is a herbivore and therefore lives purely on the nutrients from plants. 
• Deer are also herbivores, they eat plants and grasses. So, they belong to the same trophic level.

Food webs can be constructed to describe the species interactions. The fundamental purpose of food webs is to describe feeding relationship among species in a community.

The food chain is the series or linear link of different organisms through which the nutrients flow from one level to another. The trophic levels are denoted by the flow of energy from one level to the next level. The levels in any ecosystem is known by the organisms which are connected with each other by the transfer of energy.

Primary consumers are the organisms that feed on producers. Since the bird is feeding on berries (producer), it is a primary consumer. The organisms that feed on primary consumers are termed as secondary consumers. Since the bird is feeding on insects (primary consumer), it is a secondary consumer as well. This makes option D correct answer. 

An ecosystem is made up of organisms that differ in the energy source that they depend on upon and how they provide energy for other organisms in the food web. The steps of the nutritive food chain in the ecosystem is known as trophic levels. In other words, it is the position that an organism occupies in a food chain depending on what it eats, and what eats it.

Phytoplanktons are the major producers and constitute the base of five level food web of the marine ecosystem. They convert chemical energy into the usable form of energy. Zooplanktons and other herbivores feed on phytoplanktons and these herbivores are themselves eaten by higher level consumers. Fishes and whales occupy higher level as consumers. Kelps occupy the base of the food web in kelp beds only. The correct answer is option A.

With each trophic level, only 10% potential energy is transferred and 90% is lost as heat in respiration. The longer the food chain, the lesser is the energy transfer efficiency. To increase the energy transfer efficiency, food chains must be smaller with a limited number of trophic levels. Thus, the correct answer is C.

A trophic level is the specific position an organism occupies in a food chain or food web, based on its feeding source.

Trophic level refers to each levels in the  ecological pyramid and is designated as per their position in the food chain. The trophic level starts from 1 -which represents the primary producers and it moves upto  primary consumers- level 2, secondary consumers -level 3 and tertiary consumers at level 4 or 5. In an aquatic ecosystem, the phytoplanktons are the pioneers and primary producers along with the algae and cyanobacteria. Standing crop refers to the mass of living material present at a trophic level at a particular time. The ecological succession takes place from primary to secondary and reaches a climax stage. primary succession refers to the ecological succession that takes place where no living organisms ever existed. for eg. the sucession that occurs in a newy cooled lava.  Moreover, it has been seen that the rate of succession is faster in secondary than the primary succession as soil is already present in case of secondary succession.

In a food chain where a deer feeds on producers and lion feeds on the deer then, the deer is a first order consumer and the lion is a second order consumer, and as the lion feeds in the deer, lion is the predator and the deer is the prey. 

When different food chains from different ecosystems (like grassland and forest) interact or overlap, the resulting complex network is described as a food web.

A food chain is a single linear path of energy flow, whereas a food web is a collection of many interlinked food chains that better represent the complexity of an ecosystem.

Apex of the food pyramid is the tip of the food pyramid. In the given food pyramid, peacock eats snakes which eat hoppers which in turn eats leaves of the plants. Hence, the peacock is the apex of food pyramid and plants are the base of the food pyramid.  Hoppers are primary consumer and snakes are secondary consumers of the given food pyramid.

Food web is interconnected food chains in an ecosystem. Extinction of a species in a food chain is compensated in food web. When a particular species in a food chain becomes extinct, it is compensated by the remaining generalized species at the same trophic level.

In a food chain, the carnivores eat up herbivores, or in other words, the secondary consumers consume the primary consumers. So, we can say that if the number of carnivores decreases, the number of herbivores like deer go on decreasing as they will not get eaten up. So, removal of most of the carnivores will result in an increased population of deer. 

Food web is constituted by various interlinked food chains in a community. Networking of different food chains in an ecosystem provides stability to the ecosystem. Due to interconnecting food chains, relationships between the species remain constant over relatively long periods of time.

In an ecosystem, there are various trophic levels. Each trophic level consists of a particular organisms. It consists of producers, consumers, decomposers. The first trophic level consists of producers such as plants. The second trophic level consists of primary consumers. The third trophic level consists of secondary consumers. There are certain organisms which occupy more than one trophic level in the same ecosystem at the same time. An example include sparrow. It feeds upon grains. Hence, it is called as primary consumer and occupies second trophic level. It also feeds upon insects. Hence, it is called as secondary consumer and occupies third trophic level.

There are various trophic levels in a food chain. The first trophic level consists of primary producers such as plant. The second trophic level consists of herbivores or primary consumers. The third trophic level consists of carnivores or secondary consumers. Decomposers are present at the top trophic level. Phytoplankton occupies the first trophic level in an ecosystem. The zooplankton feeding upon phytoplankton occupies the second trophic level in an ecosystem. Aquatic animals occupy any trophic level in an ecosystem. Aquatic animals such as zooplankton occupies first trophic level. Aquatic animals such as small fish occupies second trophic level. Aquatic animals such as large fish occupies third trophic level. The aquatic plants occupy first trophic level. 

A web of interconnected food chains is known as food web.

Trophic means food. The animals linked in the food chain form various trophic levels. A food chain is a series of organisms that eat and get eaten.

The amount of energy at each trophic level decreases as it moves through an ecosystem. As little as 10% of the energy at any trophic level is transferred to the next level; the rest is lost largely through metabolic processes as heat. Food webs illustrate how energy flows through ecosystems, including how efficiently organisms acquire and use it. Autotrophs, producers in food webs, can be photosynthetic or chemosynthetic. They use light energy to synthesize their own food, while chemoautotrophs use inorganic molecules. Heterotrophs cannot synthesize their own energy, but must obtain it from autotrophs in food webs.

A food web consists of all the food chains in a single ecosystem. Each living thing in an ecosystem is part of multiple food chains. Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem. All of the interconnected and overlapping food chains in an ecosystem make up a food web.  An ecosystem cannot support a large number of omnivores without supporting an even larger number of herbivores, and an even larger number of autotrophs and hence the biomass of autotrophs will be the heaviest as it present in abundant amount..

An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system.  Sun is the source of energy fixed by the photoautotrophs, called primary producers, like green plants. Primary consumers absorb most of the stored energy in the plant through digestion, and transform it into the form of energy they need, such as adenosine triphosphate (ATP), through respiration. A part of the energy received by primary consumers, herbivores, is converted to body heat (an effect of respiration), which is radiated away and lost from the system. 

Omnivore is a consumption classification for animals that have the capability to obtain chemical energy and nutrients from materials originating from plant and animal origin. Often, omnivores also have the ability to incorporate food sources such as algae, fungi, and bacteria into their diet as well. Omnivores come from diverse backgrounds that often independently evolved sophisticated consumption capabilities. Although cases exist of herbivores eating meat and carnivores eating plant matter, the classification "omnivore" refers to the adaptations and main food source of the species in general. Various mammals are omnivores in the wild,  including humans and bear species.

The trophic level of an organism is the position it occupies in a food chain. The amount of energy at each trophic level decreases as it moves through an ecosystem. As little as 10 percent of the energy at any trophic level is transferred to the next level; the rest is lost largely through metabolic processes as heat. If a grassland ecosystem has 10,000 kilocalories (kcal) of energy concentrated in vegetation, only about 1,000 kcal will be transferred to primary consumers, and very little (only 10 kcal) will make it to the tertiary level. Energy pyramids such as this help to explain the trophic structure of an ecosystem.

In nature, some organisms operate in the ecosystem not just at a single trophic level but more than one trophic levels which means that it may derive its food from more than one source. The organism may get eaten itself by another organism of higher trophic level. It may also feed on different organisms of lower trophic levels. In this way, various food chains are linked together in an ecosystem and the intersection of these food chains form a complex network called food web. 

Trophic levels in an ecosystem are formed by organisms linked in food chain. It starts from producer level and usually ends at secondary or tertiary consumer levels.

Mollusc constitutes the second largest phylum in the animal kingdom which includes a group of animals living on land, in marine water, and in fresh water. Mollusks include both herbivores and carnivores animal. They eat both plants and small animals. In an aquatic ecosystem, a mollusk acts as primary consumers, so it belongs to second trophic level (T2).

Marine food webs are generally more complex and involve a higher number of species and trophic interactions compared to most terrestrial ecosystems.

Heterotrophs are organisms that cannot produce their own food and must consume other organisms (producers or other consumers) to obtain energy.

The Slow Food Movement was founded by Carlo Petrini in Italy in 1986 as a protest against the opening of a McDonald's near the Spanish Steps in Rome.

Planktons are the small or microscopic organisms that drift or swim weakly in a body of water, including bacteria, diatoms, jellyfish and various larvae. Plankton is an important food source for fish and other larger organisms. They cannot swim against a current.

• A food chain is a linear path in which an organism gets food, it starts with plants and ends with animals. A network of many food chains is called a food web. 
• A food web consists of all the food chains in a single ecosystem. Each living thing in an ecosystem is part of multiple food chains. 
• Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem. All of the interconnected and overlapping food chains in an ecosystem make up a food web.

The trophic structure in a community is the feeding relationships between species as the first level is occupied by producers and then primary and secondary consumers decomposers and so on have a successive trophic level.