Energy flow in a food chain - class-XII

Raymond Lindeman gave the famous 10 % law. According to this law, at each trophic level, only 10% of the energy of the subsequent trophic levels is transmitted. So, the amount of energy goes on decreasing at each tropic level.

Ecosystem dynamics are primarily driven by the continuous flow of energy through trophic levels and the cycling of essential chemical nutrients through the biotic and abiotic components.

The flow of energy in the ecosystem is unidirectional. The energy enters the plants (from the sun) through photosynthesis during the making of food. This energy is then passed on to the successive trophic levels in a food chain is only 10% and rest energy get lost as heat during transfer and life process. 

Only 10 percent of the gross productivity of producer is entrapped by herbivores for their body-building. Herbivores are eaten by primary carnivores. Only 10 percent of the herbivore productivity is utilised by carnivores. Higher carnivores are similarly able to retain only 10 percent of energy present in primary carnivores. This is called as 10 percent law by Lindeman.

A food chain is series of plants/animals which are interrelated in the form of organism being eaten as food by the other. It consists of producers, consumers and decomposers. The energy enters in an ecosystem through producers. Plants are producers which convert solar energy into chemical energy through photosynthesis. From producers, the energy is then transferred to the herbivores and carnivores. The animals eating plants are called as primary consumers or herbivores and animals eating primary consumers are called as secondary consumers or carnivores. Decomposers are those which decay the waster organic matter and release energy back in the environment.

Flow of energy in different trophic levels of an ecosystem is called as bioenergetics. It is also called as energy flow. In this, there is flow of energy through the food chain. Solar energy is converted to chemical energy by photosynthetic plants. From plants, the energy is transferred to primary consumers and secondary consumers in a food chain. Decomposers release energy back to the environment by decomposing organic waste matter.

Lindeman's trophic efficiency rule was introduced by Reymond Lindeman. According to this rule, the 10% of transfer of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy is lost during transfer of energy and during respiration. The first trophic level has the maximum energy. 

• According to the 10% rule when energy is passed in an ecosystem from one tropic level to the next, only 10% of the energy is passed on and the rest is wasted.
  
• 10% of (10% of 5 joules)=Energy transferred to the lion.
• So, the correct choice is '0.05 joules'.

According to 10% law of Lindemann, if 1 tonne (1000 kg) biomass is present in grass, only 10% of it means 100 kg will go into deer and in tiger the biomass will be only 10 kg, i.e. 10% of deer's biomass.

An ecosystem is normally an open system because there are a continuous and variable entry and loss of energy and material. The ecosystem is the basic fundamental unit of ecology which includes both the organism and the non-living environment is influencing the property of each other and is necessary for the maintenance of life. The whole Earth can be known as biosphere or ecosphere.

• The pyramid of energy shows the relationship between the flow of energy and different trophic level.
• The pyramid of energy depicts the flow of energy in the ecosystem.
• The source of energy in an ecosystem is the sun, the producers trap the solar energy and use it for photosynthesis which is in turn eaten by organisms of the higher trophic level such as primary consumers, secondary consumers.
• So, the correct answer is 'The rate of flow of energy through the food chain'.

The cost of ether ecosystem services like recreation and nutrient cycling are > 10% each.

An ecosystem comprises of biotic and abiotic components which interact with each other to maintain an equilibrium. A major focus of ecosystem ecology is on functional processes, ecological mechanisms, that maintain the structure and services produced by ecosystems. These include primary productivity (production of biomass), decomposition, and trophic interactions. The various trophic levels of an ecosystem interact with each other by  a flow of energy and cycling of materials from one trophic level to the other.

A food cycle is associated with energy flow in the ecosystem. It contains several trophic levels which are interdependent to each other for energy. Only 10% of energy can be transferred to the successive trophic level and rest 90% get utilise in their life processes.

Free energy cycle is the unidirectional cycle in our ecosystem. In other cycles like oxygen cycle, carbon dioxide cycle and water cycle, the basic elements are circulated and cycled whereas, in free energy cycle, energy flows from solar energy to producers and then consumers to decomposers. 

The number of trophic levels in the grazing food chain is restricted as the transfer of energy follows 10 per cent law only 10 per cent of the energy is transferred to each trophic level from the lower trophic level.

The ten percent law for the transfer of energy from one trophic level to the next was introduced by Raymond Lindeman (1942). 

Bioenergetics is a field in biochemistry, that concerns energy flow through living systems. This includes the study of different cellular processes, such as cellular respiration and the many other metabolic processes, that can lead to production and utilization of energy in forms such as ATP molecules.

The ten percent law for the transfer of energy from one trophic level to the next was introduced by Raymond Lindeman (1942). According to this law, during the transfer of energy from organic food from one trophic level to the next, only about ten percent of the energy from organic matter is stored as flesh. The remaining is lost during transfer, broken down in respiration, or lost to incomplete digestion by higher trophic levels.

Pyramids of numbers describes the relationship between organisms at successive trophic levels in terms of their number. In grassland, the producers, which are mainly grasses are always maximum in number as compared to the  primary consumers, the secondary consumers like snakes and lizards are lesser in number than the rabbits and mice. Finally, the top (tertiary) consumers like hawks or other birds are least in number. Thus, the pyramid becomes upright.

The physical components of the environment are also known as abiotic components. They include soil, water, air, climate, temperature and sunlight. It determines the type of habitat or living conditions of the living population. Thus the correct answer is option A.

According to the 10%  law, in a terrestrial ecosystem during the transfer of energy from one trophic level to the next, about ten percent of the energy in the form of organic matter is eaten and digested and stored as flesh. The remaining is lost during transfer in the form respiration or incomplete digestion. Thus the correct answer is option A.

Lindemann (1942) put forth ten percent law for the transfer of energy from one trophic level to the next. According to the law, during the transfer of organic food from one trophic level to the next, only about ten percent of the organic matter is stored as flesh. The remaining is lost during transfer or broken down in respiration.

Plants utilise sun energy for primary production and can store only 10% of the utilised energy as net production available for the herbivores. When the plants are consumed by animal, about 10% of the energy in the food is fixed into animal flesh which is available for next trophic level (carnivores). When a carnivore consumes that animal, only about 10% of energy is fixed in its flesh for the higher level.

So at each transfer 80 - 90% of potential energy is dissipated as heat (second law of thermodynamics) where only 10 - 20% of energy is available to the next trophic level.

Therefore, the correct answer is option A.

The flow of energy is always unidirectional. The energy passes from primary producers to primary consumers. From the primary consumers, the energy is passed to secondary consumers and then to tertiary consumers. Thus the energy pyramid is always upright.

Energy transfer along each trophic level of a food chain exhibit loss of 90% energy as heat and transfer of only 10% energy to the next trophic level. The energy is lost in metabolic activities. According to this, out of 400,000kJ energy of primary producers, 40000kJ will be transferred to primary consumers and 4000kJ will be transferred to the secondary consumer. Tertiary consumers will obtain only 400kJ energy from secondary consumers while top consumers will obtain as little as 40kJ energy. Correct answer is option C.

Energy is not conserved in the sense that it stays in an ecosystem; it is continuously lost as heat during each transfer between trophic levels. It must be constantly replenished by the sun.

According to the 10 percent law, when energy is passed in an ecosystem from one trophic level to the next, only ten percent of the energy will be passed on.  The remaining is lost during transfer, broken down in respiration, or lost to incomplete digestion by higher trophic levels.

10 percent Law introduced by Lindeman states that only 10% of energy is transferred from one trophic level to another and 90% of the energy is lost during transfer, respiration and digestion processes. Therefore if plants (present at producers level) produces 100 units of energy, 10% of it will be transferred to primary consumers (10 units of energy) and 10% of the subsequent energy is transferred to secondary consumers (1 unit of energy). Hence, the correct answer is option A.

The transfer of energy from one trophic level to another follows the 10% law of energy transfer. So, of the total energy created only 10% is passed on from the producers to the consumers while rest is used by the producer to carry out its activities

Higher animals like mammals tend to maintain a constant internal environment despite changes in external environment. This is called as homeostasis, e.g., in humans a body temperature around 97 fahrenheit is considered normal. In summers when outside temperature is high or in winters when outside temperature is very low the body temperature remains constant. This is one example of homeostasis. The nervous and endocrine system closely interplay to maintain homeostasis. Therefore, the correct answer is option D.

The transfer of energy in an ecosystem is always one way, from the sun to producers, from producers to herbivores, from herbivores to carnivores. The one way transfer of energy is in accordance with the laws of thermodynamics. 

Ecosystem require a constant input of energy as every component of an ecosystem is regularly dissipating energy. Two laws of thermodynamics govern this flow of energy. 

The ecosystem is an interaction between living beings (biotic component) and their physical environment (abiotic component).

Ecosystems are characterized by the flow of energy, the cycling of materials (nutrients), and the flow of information (e.g., biological signals). Smoke is not a standard component of ecosystem functional flow.

The first trophic level is represented as T$ _1$. It includes producers. The second trophic level is represented as T$ _2$. It includes primary consumers. Similarly, third trophic level is represented as T$ _3$. It includes secondary consumers. In terrestrial ecosystem, maximum energy is present in T$ _1$, that is producers.

Large amount of assimilated energy is used in respiration. In herbivores, 30% of assimilated energy is used in respiration. Herbivores are more efficient in using energy for their growth and development than animals. Hence, plants grow faster than animals. 

Energy flow is the amount of energy that flows from one trophic level to another trophic level in an ecosystem. It is unidirectional or one-way passage. In an ecosystem, flow of free energy occurs through different trophic levels. Producers or plants obtain their energy from the sun by photosynthesis. The primary consumers (herbivores) obtain their energy from the producers. The secondary consumers (carnivores) obtained their energy by using herbivores as a source of food and so on. The energy present at each successive trophic level is 10% of the previous trophic level.

Ecosystem is made up of living and nonliving things. Living things or biotic things include plants and animals. Nonliving things or abiotic things include air, water, land.  It is composed of organisms interacting within communities. The driving force for an ecosystem is solar energy. Producers use solar energy to synthesize their food by the process of photosynthesis. From producers, the energy is transferred to herbivores. Herbivores eat producers. The energy is transferred from herbivores to carnivores. Carnivores eat herbivores. From carnivores, the energy is transferred to decomposers. They decompose organic matter of plants and animals.

Pyramid of energy represents the amount of energy at each trophic level. In any ecosystem, flow of energy declines as it passes from lower to higher trophic level. Hence, the pyramid of energy is always upright. Each successive trophic level has less total energy. In this, the energy decreases from one trophic level to the next trophic level because energy is lost as metabolic heat during transfer of energy. When food energy passes from producers to herbivores to carnivores, only 10% of energy is transferred from one trophic level to another trophic level.

According to the Lindeman's trophic efficiency rule, the 10% of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy, that is 90% of energy is lost during transfer of energy from one trophic level to next higher trophic level. The first trophic level has the maximum energy. 

Ten percent law of energy transfer in food chains was given by Reymond LIndeman. It is also called as Lindeman's trophic efficiency rule. According to this rule, the 10% of transfer of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy is lost during transfer of energy and during respiration. The first trophic level has the maximum energy. 

Ten percent law of energy transfer in food chains was given by Reymond LIndeman. It is also called as Lindeman's trophic efficiency rule. According to this rule, the 10% of transfer of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy is lost during transfer of energy and during respiration. The first trophic level has the maximum energy. 

In a food chain, energy enters through producers. Producers such as plants synthesize their own food in presence of sunlight. They convert solar energy into chemical energy. From producers, the energy flows to the primary consumers to the secondary consumers to the tertiary consumer. Hence, the energy flow in a food chain is always from low to high level. During energy transfer, only 10% of energy is transferred from one trophic level to another trophic level.

Ten percent law of energy transfer in food chains was given by Reymond LIndeman. It is also called as Lindeman's trophic efficiency rule. According to this rule, the 10% of transfer of energy is transferred from one trophic level to the next successive trophic level. The rest of the energy is lost during transfer of energy and during respiration. The first trophic level has the maximum energy. 

Statement II is false because the grazing food chain is often the major conduit in aquatic ecosystems, while the detritus food chain is more significant in terrestrial ecosystems. Statement III is false because the detritus food chain is the major conduit in terrestrial ecosystems.

• A hunter-gatherer is a human living in a society in which most or all food is obtained by foraging (collecting wild plants and pursuing wild animals).
• The energy required daily by hunter-gatherer humans was 2000 - 4000 kcal.
  
• So, the correct answer is ' 2000 - 4000 kcal'.

Energy flow is the amount of energy that flows from one trophic level to another trophic level in an ecosystem. It is unidirectional. In any given ecosystem, flow of energy occurs through different trophic levels. Producers or plants obtain their energy from the sun by photosynthesis. The primary consumers (herbivores) obtain their energy from the producers. The secondary consumers (carnivores) obtained their energy by using herbivores as a source of food and so on. The energy present at each successive trophic level is 10% of the previous trophic level. Hence, as biomass passes from one trophic level to another, the amount of total energy declines.

In an ecosystem, the ultimate source of energy is sun and solar energy is trapped by photoautotrophs or green plants which then convert it into chemical energy which is stored in carbohydrates. This chemical energy in the form of food is passed on from one organism to another in a food chain in the ecosystem. 

• Bioenergetics is a field in biochemistry and cell biology that concerns energy flow through living systems. 
• This is an active area of biological research that includes the study of the transformation of energy in living organisms and the study of thousands of different cellular processes such as cellular respiration and the many other metabolic and enzymatic processes that lead to production and utilization of energy in forms such as adenosine triphosphate (ATP) molecules. 
• That is, the goal of bioenergetics is to describe how living organisms acquire and transform energy in order to perform biological work. 
• The study of metabolic pathways is thus essential to bioenergetics.
  

An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. Ecosystems maintain themselves by cycling energy and nutrients obtained from external sources. The low rate of energy transfer between trophic levels makes decomposers generally more important than producers in terms of energy flow. Decomposers process large amounts of organic material and return nutrients to the ecosystem in inorganic form, which are then taken up again by primary producers.

Fats typically provide more than half of the body's energy needs. Fat from food is broken down into fatty acids, which can travel in the blood and be captured by hungry cells. Fatty acids that aren't needed right away are packaged in bundles called triglycerides and stored in fat cells, which have unlimited capacity. Fat is the body's most concentrated source of energy, providing more than twice as much potential energy as carbohydrate or protein (9 calories per gram versus 4 calories each per gram).

Entropy is the measurement of this disorder in energy, in which heat energy, is not usable, is considered disorganized. Thus, a system with a large amount of usable energy has low entropy, a system with little usable energy has high entropy. Based on the second law of thermodynamics, entropy will continually increase in the universe as energy becomes more and more disorganized.

First law of thermodynamics defines that the energy neither created nor destroyed but can only be transformed. Ecosystem is not accepted by the 1st law of thermodynamics because the energy is created.

Kinetic energy is defined as the energy possessed by an object due to its motion.

The formula for heat absorption is Q = mc * deltaT. Since Q and m are the same for both, deltaT = Q / (mc). If the specific heat c is larger for A, the temperature change deltaT will be smaller for A. Therefore, B will become warmer than A.

Energy transfer in food chains is inefficient because a large portion of energy is lost as heat at each trophic level, following the second law of thermodynamics.

The average incident solar energy reaching the Earth's surface is approximately 3000 kcal/m2/day, though this varies by location and season.

The energy flow starts from the sun. The light energy enters the space and then into the atmosphere. The energy in the atmosphere is captured by the plants which are autotrophs. Plants convert this light energy to chemical energy by photosynthesis. The food prepared by the plants is consumed by the heterotrophs. The heterotrophs are utilized by the decomposers.

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. The efficiency with which energy or biomass is transferred from one trophic level to the next is called as the ecological efficiency. Consumers at each level convert on average only about 10% of the chemical energy in their food to their own organic tissue (the ten-percent law). 

Flow of energy declines as it passes from lower to higher trophic level. This is explained by second law of thermodynamics. According to this law, the energy decreases from one trophic level to the next trophic level because energy is lost as metabolic heat during transfer of energy. When food energy passes from producers to herbivores to carnivores, only 10% of energy is transferred from one trophic level to another trophic level.

A food chain can be described as a series of energy dilutors, the energy that fails to reach the next level being dissipated as heat or movement. Most of the energy contained in the food of animal consumers is used by them during the processes of food collection, digestion, and other essential metabolic activity.

• An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. 
• Energy flow is the amount of energy that moves through a food chain. 
• Energy that is not used in an ecosystem is eventually lost as heat. 
• Energy is passed on from one trophic level to the next trophic level and each time some energy is lost as heat into the environment. 
• This is due to the fact that each organism must use some energy that they received from other organisms in order to survive. 
• The top consumer of a food chain will be the organism that receives the least amount of energy.