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Protecting Ireland’s Biodiversity Protecting Ireland’s What is ecology? Saprophytes are a particular group of decomposers – they are bacteria and fungi that feed on and decompose dead organic matter. Saprophytes, besides being food for other organisms and clearing detritus, also play a vital role in the recycling of mineral nutrients. This lesson introduces the subject of ecology and the concept of the ecosystem. We then go on to discuss habitats, the food chain, and the pyramid of numbers. We will also learn about Teagasc, the state agency providing environmental advice, research and training. The oak forest was the most widespread ecosystem in Ireland before the arrival of humans. An oak forest ecosystem is twice as productive Saprophytes arehasatwice particular group of decomposers – they are as agricultural land. A hectare of oak forest as much organic �������� and fungi that matter remaining than abacteria hectare of wheat has, after the feed plants on haveand takendecompose dead organic matter. what they need for theirSaprophytes, energy needs. besides being food for other organisms and clearing What is ecology? Ecology the studyintroduces of the interactions livingof organisms andand of This islesson thebetween subject ecology the concept their interactions with their abiotic environment. detritus, also play a vital role in the recycling of mineral nutrients. ������� of the ecosystem. We then go on to discuss habitats, the food learn about Teagasc, the state agency providing environmental advice, The boundaries between ecosystems are not sharply defined but research and training. ���� gradual. This means that there can be considerable interchange between Living organisms live in communities. A community is a group of species chain,with and of same numbers. We will plus also interacting eachthe otherpyramid and living in the area. The community the abiotic environment with which it interacts is called an ecosystem. ecosystems. All the ecosystems of our planet are connected to form a Ecology is the study of the interactions between living organisms giant ecosystem called the biosphere. The biosphere is the layer of living their interactions theirextending abiotic environment. organisms that covers with the earth in depth from 3 km below ground to the highest level of the atmosphere. The oak forest was the most widespread ecosystem in Ireland before � the����������������� arrival of humans. An oak forest ecosystem is twice as productive ���� ������������������������ as������������������� agricultural land. A hectare of oak forest has twice as much organic ������������ matter remaining than a hectare of wheat has, after the plants have taken what they need for their energy needs. ��������������� and of ���� Living organisms live in communities. A community is a group of species ��������� ������������������������ interacting with each other and living in the same area. The community plus What is the difference the abiotic environment with which it interacts is called an ecosystem. ��������� �������� ����������������� ������������������������ ������������������� between habitat and ecosystem? The boundaries between ecosystems are not sharply defined but Ecosystem refers to a community whereas habitat is restricted to an gradual. This means thatis there canwhere be considerable interchange between individual species. The habitat the place the species is living ecosystems. All the has ecosystems ofspecies’ our planet are connected to form a���� and to which the species adapted. The distribution may begiant limitedecosystem to only a small part of ecosystem where a unique set is of the layer of living called thethebiosphere. The biosphere conditions occurs. ���� ����������� ���� ����������������� ���� organisms that covers the earth extending in depth from 3 km below Adaptations arethe ‘solutions’ to level environmental ‘problems’ and have arisen ground to highest of the atmosphere. gradually as a result of evolution by natural selection. Human induced environmental changes to habitats or ecosystems often lead to the extinction of species because they cannot tolerate the new conditions. Therefore, the conservation of biodiversity demands the maintenance or re-establishment of habitats and ecosystems. What is the difference between habitat and ecosystem? Ecosystem to a community process? whereas habitat is Isn’t life anrefers energy-requiring ����� Fig.1 Energy flow in an ecosystem What�������� are the reasons for constructing a pyramid of What is a food chain? A pyramid of numbers attempts to discover of an ecosystem as a bar chart by counting each trophic level. The number of organism pyramid. This is due to the large energy los trophic level. As a result there is less energy up the pyramid. A food chain is a sequence of species, each being the source of food for the next species. The position of a species in a food chain is called its restricted an trophicto level. individual species. The habitat is the place where the species is living Adaptations are ‘solutions’ to environmental ‘problems’ and have�������� arisen ��������� as a result of evolution by natural selection. Human induced Isgradually food just a source of energy? environmental changes to habitats or ecosystems often lead to the No. Food made by photosynthesis, is also a source of organic materials extinction of species because they cannot tolerate the new conditions. needed for the physical construction of living organisms. Approximately Therefore, conservation of biodiversity the maintenance or 90% of the food the obtained by an organism is used as a fueldemands for energy and re-establishment of habitats and ecosystems. 10% or less is used as building material. Producers obtain their food by making it for themselves from inorganic materials, either by photosynthesis or chemosynthesis. Consumers obtain their food by feeding on organic materials made by other organisms. ���� �������� �������� �������� ���������� �������� �������� Every species in ������������ the community is said t A niche is often considered to be the mann environment in the struggle to obtain its esse organism’s most important resource, so all f food are vital parts of a species’ niche. ��������� ��������� ������������������������ Yes it is. The average human at rest uses 100 joules of energy every and –tothis which the species adapted. The species’ second is equivalent to a 100 has watt light bulb. We obtain most of distribution may beenergy limited to onlyrespiration a small ofpart of Plants the ecosystem where our by aerobic ‘food’. originally made this a unique set of food during photosynthesis conditions occurs. when light energy was converted to chemical energy. Therefore light is the energy for life. What is the role of a speci in a ���� community called? ����������� ���� ����������������� ��������� �������� ������� Fig.1 Energy flow in an ecosystem 100 Tertiary Co 5,000 What is a food chain? Fig.2 Example of a food chain Most species are members of more than one chain in the A food chain is afood sequence ofcommunity. species, each Amalgamating all the food chains one flow chart a food the nextintospecies. Theproduces position of aweb. species Isn’t life an energy-requiring process? level. The food web gives all trophic the feeding connections in the community and a clearer picture of the complexity of energy flows. It also indicates the Animals that feed on plants are called herbivores. Those that feed on other Yes it is. The average human at rest uses 100 joules of energy every delicate balance of nature because if one species is lost, or if its population animals are carnivores. If their food consists of plants and animals, they is changed dramatically, all the other species will be affected. Pollution can – this is organisms equivalent a 100 watt light bulb. We obtain most of aresecond omnivores. If dead areto their food source they are called very destructive in ecosystems if it leads to the elimination of sensitive decomposers. make up about 80% of ecosystem. our energyOmnivores by aerobic respiration ofeach ‘food’. Plants originally be made this species or severe reduction of their populations. 9 5 x 10 being the source of food for in a food chain is called its Relative Number of Organisms F food during photosynthesis when light energy was converted to chemical energy. Therefore light is the energy for life. Is food just a source of energy? No. Food made by photosynthesis, is also a source of organic materials needed for the physical construction of living organisms. Approximately 90% of the food obtained by an organism is used as a fuel for energy and 10% or less is used as building material. Producers obtain their food by making it for themselves from inorganic materials, either by photosynthesis or chemosynthesis. Consumers obtain their food by feeding on organic materials made by other organisms. Animals that feed on plants are called herbivores. Those that feed on other animals are carnivores. If their food consists of plants and animals, they are omnivores. If dead organisms are their food source they are called decomposers. Omnivores make up about 80% of each ecosystem. �������� ��������� �������� �������� �������� Second 106 ���������� �������� �������� ��������� �������� ������� Fig.2 Example of a food chain Most species are members of more than one food chain in the community. Amalgamating all the food chains into one flow chart produces a food web. The food web gives all the feeding connections in the community and a clearer picture of the complexity of energy flows. It also indicates the delicate balance of nature because if one species is lost, or if its population is changed dramatically, all the other species will be affected. Pollution can be very destructive in ecosystems if it leads to the elimination of sensitive species or severe reduction of their populations. Protecting Ireland’s Biodiversity d’s Biodiversity What is ecology? Saprophytes are a particular group of decomposers – they are bacteria and fungi that feed on and decompose dead organic matter. Saprophytes, besides being food for other organisms and clearing detritus, also play a vital role in the recycling of mineral nutrients. This lesson introduces the subject of ecology and the concept of the ecosystem. We then go on to discuss habitats, the food chain, and the pyramid of numbers. We will also learn about Teagasc, the state agency providing environmental advice, research and training. The oak forest was the most widespread ecosystem in Ireland before the arrival of humans. An oak forest ecosystem is twice as productive as agricultural land. A hectare of oak forest has twice as much organic matter remaining than a hectare of wheat has, after the plants have taken what they need for their energy needs. Ecology is ����� the study of the interactions between living����� organisms and of their interactions with their abiotic environment. � ����������������� ������������������������ ������������������� The boundaries between ecosystems �������� are not sharply defined but ���������� gradual. This means that there can be considerable interchange between ecosystems. All the ecosystems of our planet are connected to form a giant ecosystem called the biosphere. The biosphere is the layer of living organisms������� that covers the earth extending in depth from 3 km below ground to the highest level of the atmosphere. ���� ���� ������������ ��������������� ��������� ����� What is the difference between habitat and ecosystem? �������� ������� Living organisms live in communities. A community is a group of species interacting with each other and living in the same area. The community plus the abiotic environment with which it interacts is called an ecosystem. ������������ ����� ������������������������ Ecosystem refers to a community whereas habitat is restricted to an individual species. The habitat is the place where the species is living and to which the species has adapted. The species’ distribution may ��������������� be limited to only a small part of the ecosystem where a unique set of conditions occurs. ���� Teagasc is a state organisation which provides research, ���� advisory and training services for the agriculture and food industry in Ireland.��������� Over 1,500 staff work at over 100 locations �������� throughout the country. They work with all sectors of the What is the role of a speci agriculture and food industries and with development in rural a community called? agencies. Teagasc employs over 200 scientists and 300 Every species in the community is said t research technicians in research, and many specialistto be the mann A niche other is often considered ����������� environment in the struggle to obtain its esse staff in training and ����advisory roles. ����������������� organism’s most important resource, so all f parts of a species’ One of the organisation’s objectivesfood is aretovitalprotect and niche. Adaptations are ‘solutions’ to environmental ‘problems’ and have arisen enhance biodiversity on farmland. This programme includes Fig.3 Food web Fig.1 Energy flow in an ecosystem gradually as a result of evolution by natural selection. Human induced the provision of advice to farmers onWhat how to the areprotect the reasons for environmental changes to habitats or ecosystems often lead to the environment in designated areas. These areas include extinction of species because they cannot tolerate the new conditions. constructing a pyramid of What isconservation the role of a demands species Therefore, the of biodiversity the maintenance or habitats of high conservation value that contain rare or What is a food chain? A pyramid of numbers attempts to discover re-establishment of habitats and ecosystems. important species, species-rich sand in a community called? of angrasslands, ecosystem as a bar chart by counting A food chain is a sequence of species, each being thesuch source as of food for each trophic level. The number the next species. The position of a marshes, species in a food is called its dunes, andchain bogs. Teagasc also provides advice to of organism Every species in the community is said to occupy a particular niche. pyramid. This is due to the large energy los Isn’t life an energy-requiring process? trophic level. farmers on the protection and management of other habitats trophic level. As a result there is less energy A niche is often considered to be the manner in which a species uses its Yes it is. The average human at rest uses 100 joules of energy every that commonly occur on Irish farmlandupe.g. streams, rivers, the pyramid. environment the struggle to obtain essential resources. second – this isinequivalent to a 100 watt lightitsbulb. We obtain most of Food is every ponds, hedgerows, field margins, and woodland. Ireland our energy bymost aerobic respirationresource, of ‘food’. Plants this organism’s important so alloriginally factors made connected with gaining food during photosynthesis light energy was converted to chemical has a wide diversity of wildlife habitats and it is particularly food are vital parts of awhen species’ niche. energy. Therefore light is the energy for life. important that they are protected. Its research aims to raise �������� �������� ���������� ��������� awareness�������� about farmland wildlife and to design management ��������� �������� �������� 100 Tertiary Co �������� �������� ������� Is food just a source of energy? practices to help farmers better protect species and habitats What are the reasons for 5,000 Second No. Food made by photosynthesis, is also a source of organic materials on their land. constructing a pyramid of numbers? needed for the physical construction of living organisms. Approximately Fig.2 Example of a food chain 106 90% of the food obtained by an organism is used as a fuel for energy and You can visit www.teagasc.ie to find out about designated are omnivores. If dead organisms are their food source they are called decomposers. Omnivores make up about 80% of each ecosystem. is changed dramatically, all the other species will be affected. Pollution can www.teagasc.ie and at www.sciencetechologyaction.com be very destructive in ecosystems if it leads to the elimination of sensitive species or severe reduction of their populations. A pyramid numbers attempts 10% or less isofused as building material.to discover and show the energy structure and get fascinating information on habitats. 5 x 109 of an ecosystem as a bar chart by counting the number of individuals at are membersareas Most species of more than one food chain in the community. Producers obtain their food by making it for themselves from inorganic Amalgamating each trophic level. The number of organisms declines as you go up the all the food chains into one flow chart produces a food web. materials, either by photosynthesis or chemosynthesis. Consumers obtain their food byThis feeding on organic made by other pyramid. is due to thematerials large energy loss organisms. (about 90%) between Relative Number of Organisms The each food web gives all the feeding connections in the community and Find outof about Teagasc, the people who work there a clearer energy flows. It also indicates the trophic level. result less energy organisms higherpicture of the complexity Animals that feedAs on a plants arethere called is herbivores. Thoseavailable that feed onto other delicate balance of nature and because species is lost, or if projects its population theif one many scientific they are involved in at animals are carnivores. If their food consists of plants and animals, they up the pyramid. 100 5,000 106 5 x 109 Relative Number of Organisms Tertiary Consumer Secondary Consumer Primary Consumer Primary Producer Trophic Level Fig.4 Pyramid of numbers Fig.5 Manmade lake This manmade lake on farmland supports a variety of aquatic invertebrates and plants, and is surrounded by common reed, shrubs mature trees that provide habitat for terrestrial insects and birds. F Protecting Ireland’s Biodiversity Protecting Ireland’s What is ecology? Saprophytes are a particular group of decomposers – they are bacteria and fungi that feed on and decompose dead organic matter. Saprophytes, besides being food for other organisms and clearing detritus, also play a vital role in the recycling of mineral nutrients. This lesson introduces the subject of ecology and the concept of the ecosystem. We then go on to discuss habitats, the food chain, and the pyramid of numbers. We will also learn about Teagasc, the state agency providing environmental advice, research and training. The oak forest was the most widespread ecosystem in Ireland before the arrival of humans. An oak forest ecosystem is twice as productive as agricultural land. A hectare of oak forest has twice as much organic matter remaining than a hectare of wheat has, after the plants have taken what they need for their energy needs. Syllabus Reference Activities Ecology is the study of the interactions between living organisms and of their interactions with their abiotic environment. Leaving Certificate Biology: �������� Practical Activities Living live in communities. A community is 1.4.3 a groupBiosphere, of species Unit organisms 1.4.1 Ecology, 1.4.2 Ecosystem, interacting with each other and living in the same area. The community plus 1.4.4 Habitat, 1.4.5 Environmental Factors, 1.4.6 Energy the abiotic environment with which it interacts is called an ecosystem. gradual. This means that there can be considerable interchange between Junior Certificate Science: ecosystems. All the ecosystems of our planet are connected to form a giant called the biosphere. The biosphere is the layer of living 1C7ecosystem Ecology organisms that covers the earth extending in depth from 3 km below ground to the highest level of the atmosphere. ������� Revise the following mandatory practical activities: Flow, 1.4.7 Niche, H.1.4.10 Pyramid of Numbers (Extended Study) The boundaries between ecosystems are not sharply defined but � ����������������� ���� five flora using simple keys. •������������������������ Identify five fauna and ������������������� ���� What is the difference between habitat and ecosystem? Learning Objectives ������������ • Identify and use various apparatus required for collection methods in ��������������� an ecological study. • Conduct a quantitative study of plants and animals of a sample area of the selected ecosystem. ��������� • Investigate any three abiotic factors present in the selected What is the role of a speci ecosystem. ��������� ������������������������ Ecosystem refers to a community whereas habitat is restricted to an individual species. The habitat is the place where the species is living Ontocompleting this student willmay be and which the species has section, adapted. Thethe species’ distribution be limited to only a small part of the ecosystem where a unique set of • Define ecology conditions occurs. ����� ���� �������� Investigative Activities able to: ���� • in a community called? Every species in the community is said t A niche is often considered to be the mann ����������� Identify and record���� the common plants and animalsinencountered in its esse environment the struggle to obtain ����������������� organism’s most important resource, so all f every day life. food are vital parts of a species’ niche. • Record any feeding activity you observe – note the animal, time, place Adaptations arethe ‘solutions’ to environmental ‘problems’ and haveecosystems arisen • Outline relationships between communities, and the Fig.1 Energy flow in an ecosystem and food source. gradually as a result of evolution by natural selection. Human induced biosphere What are the reasons for environmental changes to habitats or ecosystems often lead to the • Record any adaptive feature you become aware of in any of the plants extinction of species because they cannot tolerate the new conditions. constructing a pyramid of • Differentiate between a habitat and an ecosystem Therefore, the conservation of biodiversity demands the maintenance or and animals. What is a food chain? A pyramid of numbers attempts to discover re-establishment of habitats and ecosystems. • Identify general groupings of organisms based on their foodAsources of an ecosystem as a bar chart by counting food chain is a sequence of species, each being the source of food for each trophic level. The number of organism the next species. The position of a species in a food chain is called its • Differentiate between a food chain and a food web pyramid. This is due to the large energy los Isn’t life an energy-requiring process? trophic level. trophic level. As a result there is less energy Yes is. The average human of at a rest uses 100 of energy every • itExplain the function pyramid ofjoules numbers up the pyramid. second – this is equivalent to a 100 watt light bulb. We obtain most of our energy by aerobic respiration of ‘food’. Plants originally made this food during photosynthesis when light energy was converted to chemical Indicate whether the following are true (T) or false (F) energy. Therefore light is the energy for life. True or False Is food justLearning a source ofPoints energy? General No. Food made by photosynthesis, is also a source of organic materials needed for the physical construction of living organisms. Approximately • Living organisms live in interactive communities. 90% of the food obtained by an organism is used as a fuel for energy and 10% less is used as buildinginfluence material. • or Living organisms and are influenced by �������� ��������� by drawing a circle around T or F. ��������� �������� ���������� �������� �������� (a) Ecology is�������� the study �������� organisms. their abiotic �������� of the������� interactions between living (b) A group ofFig.2 interacting species in an area is known as a Example of a food chain habitat. T 100 F Tertiary Co 5,000 106 T 5 x 109 Most species are members of more than one food chain in the community. environment. Producers obtain their food by making it for themselves from inorganic (c) The community plus its abiotic environment is a habitat. T Amalgamating all the food chains into one flow chart produces a food web. materials, either by photosynthesis or chemosynthesis. Consumers obtain • food Theby features oforganic each materials speciesmade are by solutions to the problemsThe of food life in their feeding on other organisms. Relative Number of Organisms web gives all(d) theThe feeding connectionsisinearth’s the community atmosphere layer ofand living organisms. T their particular habitat. Habitat destruction is a major cause ofa clearer species picture of the complexity of energy flows. It also indicates the Animals that feed on plants are called herbivores. Those that feed on other delicate balance of nature because if one species is lost, or if its population extinction. animals are carnivores. If their food consists of plants and animals, they (e) Sunlight is the major source of energy maintaining the T is changed dramatically, all the other species will be affected. Pollution can are omnivores. If dead organisms are their food source they are called biosphere. be very destructive in ecosystems if it leads to the elimination of sensitive • Maintaining biodiversity depends on habitat conservation. decomposers. Omnivores make up about 80% of each ecosystem. species or severe reduction of their populations. Second F F F F F • The sun is the source of energy for life on planet earth. (f) Plants are producers. T F • About 90% of food is used as a fuel, for energy, at each trophic level. T F • Food chains are short. (g) Producers are micro-organisms that feed on dead organic matter. • A food web shows all the feeding connections in the community. (h) One particular energy flow path is called a food chain. T F • All species in the biosphere are connected through the global food web. (i) The position of a species in a food chain is its trophic level. T F • Because of the complexity of food webs it is very difficult to predict the alteration within an ecosystem if a species is lost or its population undergoes a significant change. (j) Herbivores occupy the first niche. T F (k) The niche of a species describes its position in a pyramid of numbers. T F (l) A pyramid of numbers tries to show the energy structure of a community. T F • A pyramid of numbers attempts to show the energy structure of a community in a particular ecosystem. Check your answers to these questions on www.sciencetechnologyaction.com Protecting Ireland’s Biodiversity d’s Biodiversity What is ecology? Saprophytes are a particular group of decomposers – they are bacteria and fungi that feed on and decompose dead organic matter. Saprophytes, besides being food for other organisms and clearing detritus, also play a vital role in the recycling of mineral nutrients. This lesson introduces the subject of ecology and the concept of the ecosystem. We then go on to discuss habitats, the food chain, and the pyramid of numbers. We will also learn about Teagasc, the state agency providing environmental advice, research and training. The oak forest was the most widespread ecosystem in Ireland before the arrival of humans. An oak forest ecosystem is twice as productive as agricultural land. A hectare of oak forest has twice as much organic matter remaining than a hectare of wheat has, after the plants have taken what they need for their energy needs. Biographical Notes Examination Questions Ecology is the study of the interactions between living organisms and of their interactions withHigher their abiotic level environment. 2004 / 2003 Living organisms live in communities. A community is a group of species (i) Explain following terms that arearea. used ecology.plus interacting withthe each other and living in the same Thein community (a) Biosphere, (c) Consumer, Producer, the abiotic environment(b) withHabitat, which it interacts is called an(d) ecosystem. ����� Ernst Mayr (e) Niche, Ecosystem, (g) Biodiversity. The (f) boundaries between ecosystems are not sharply defined but gradual. This means that there can be considerable interchange between ecosystems. All saprophytes? the ecosystems of our planet are connected to form a (ii) What are giant ecosystem called the biosphere. The biosphere is the layer of living Outline the role of saprophytes in the biosphere. organisms that covers the earth extending in depth from 3 km below ground to the highest level of the atmosphere. ���� ��������� ������� was one of the world’s leading biologists. He was born in Germany in � 1904. One famous story is that he knew the names of all the birds in ����������������� ���� ������������������������ his locality when he was 10 years old. He received his PhD at the age ������������������� ������������ of 21. His work on birds led him to develop new theories on evolution. He is the originator of the concept of the biological species. He later ��������������� worked ���� at Harvard University where he was Professor of Zoology. He was a prolific author and published many scientific books and papers. ��������� He died in 2005 �������� ������������������������ 2004: State Examinations Commission: What is the difference Sample betweenPaper habitat and ecosystem? What is the role of a speci in a community called? Eugene Odum Ecosystem refers to a community whereas is to restricted to of anenergy through (9) Answer the following questions in habitat relation the flow individual species. The habitat is the place where the species is living an ecosystem. and to which the species has adapted. The species’ distribution may be limited to only a small part of the ecosystem where a unique set of (i) What is the source of energy for the earth’s ecosystems? conditions occurs. Adaptations are the ‘solutions’ to environmental ‘problems’ and have (ii) Name process that takes place in plants in arisen which this gradually as a result of evolution by natural selection. Human induced converted to a usable form. environmental changes to habitats or ecosystems often lead to the extinction of species because they cannot tolerate the new conditions. (iii) What substance do plants possess that allows them to Therefore, the conservation of biodiversity demands the maintenance or this conversion? re-establishment of habitats and ecosystems. ���� is one of the most influential ecologists of the 20th Century. He has Every species in the community is said t challenged many scientific assumptions about the isworld around to us. A niche often considered be the mann �����������ecosystem ecology as a new integrative He pioneered science, exploring environment in the struggle to obtain its esse ���� ����������������� organism’s most important so all f connections between pristine watersheds, plants, animals, climate resource, and food are vital parts of a species’ niche. weather. energy is carry out Fig.1 Energy flow in an ecosystem Read about these and other famous scientists What are the at reasons for www.sciencetechnolgyaction.com constructing a pyramid of What is a food chain? A food chain is a sequence of species, each being the source of food for The position of a species in a food chain is called its (iv) Energy flows along food chains. In the food chain A B the C;next give species. Isn’t an lifeexample an energy-requiring process? level. of each from the organisms you found in atrophic named Yes it is.ecosystem. The average human at rest uses 100 joules of energy every second – this is equivalent to a 100 watt light bulb. We obtain most of (v)energy Is there morerespiration energy of available for organism B orthisC? our by aerobic ‘food’. Plants originally made food during photosynthesis when light energy was converted to chemical answer. energy. Therefore light is the energy for life. �������� A pyramid of numbers attempts to discover of an ecosystem as a bar chart by counting each trophic level. The number of organism pyramid. This is due to the large energy los trophic level. As a result there is less energy up the pyramid. Explain your (vi) A food web can be thought of as a number of interlinked �������� food chains. Using the named organisms A, B, C from (iv) above��������� and three other named organisms; construct a food web that is found in No. Food made by photosynthesis, is also a source of organic materials the ecosystem you have studied. (30) Is food just a source of energy? needed for the physical construction of living organisms. Approximately 90% of the food obtained by an organism is used as a fuel for energy and (a) pyramid of numbers? 10%What or lessis is a used as building material. Producers food byinmaking it for themselves from of inorganic (b) What obtain is thetheir purpose constructing a pyramid numbers? materials, either by photosynthesis or chemosynthesis. Consumers obtain theirDraw food byafeeding on organic materials other organisms. (c) pyramid of numbers formade the by named ecosystem you �������� �������� �������� ���������� �������� �������� ��������� �������� ������� 100 5,000 Fig.2 Example of a food chain Revise the Terms Most species are members of more than one food chain in the community. Amalgamating all the food chains into one flow chart produces a food web. Did You Know? The average human uses 100 joules of energy every second. The consumers at the top of the pyramid do not represent the uppermost end of the food chain. When they die, they are eaten by tiny, microscopic organisms which serve as decomposers. When devoured by these bacteria, the nutrients are returned to the soil to be recycled into yet another food chain. In 1988, Teagasc, the Agriculture and Food Development Authority, was established as the national agency with overall responsibility for the provision of research, training and advisory services to the agriculture industry. Second 106 5 x 109 Can you recall the meaning of these terms? Reviewing the Relative Number of Organisms The food web gives all the feeding connections in the community and terminology is aflows. powerful aid for a clearer picture of the complexity of energy It also indicates the recall and retention. have Animals thatstudied. feed on plants are called herbivores. Those that feed on other delicate balance of nature because if one species is lost, or if its population animals are carnivores. If their food consists of plants and animals, they Ecology; abioticPollution environment; community; species; is changed dramatically, all the otherorganism; species will be affected. can are omnivores. If dead organisms are their food source they are called be very destructive inecosystem; ecosystems if it leads to the elimination of sensitive biosphere; habitat; adapted; species distribution; decomposers. Omnivores make up about 80% of each ecosystem. For further examples of past paper exam questionsspecies check or severe reduction of their populations. out www.scienceandtechnology.com Tertiary Co evolution; natural selection; conservation; biodiversity; aerobic respiration; food; plants; photosynthesis; chemical energy; organic material; energy flow; producer; inorganic material; chemosynthesis; consumer; feeding; animal; herbivores; carnivores; omnivores; decomposers; saprophytes; bacteria; fungi; mineral recycling; mineral nutrients; food chain; trophic level, food web; balance of nature; pollution; population; niche; resource; pyramid of numbers; pyramid of biomass; pyramid of energy. Check the Glossary of Terms for this lesson at www.sciencetechnologyaction.com F