FOOD CHAIN Afood chain is a linear sequence of links in afood webstarting from a species that are called producers in the web and ends at a species that is called decomposers species in the web. It also shows how the organisms are related with each other by the food they eat. A food chain differs from a food web because it only follows linearmonophagouspathways (feeding on or utilizing a single kind of food). A common metric used to quantify food web trophic structure is food chain length. The food chain's length provides a measure of the passage of energy and an index ofecological structurethat increases in value from the lowest to the highesttrophic levels. Food chains are often used in ecological modeling. Food chain studies have had an important role inecotoxicology studies. Food chains vary in length from three to six or more levels. All food chains must start with a producer Producers are organisms that utilize solar energy or heat energy to synthesize starch. Consumersare organisms that eat other organisms: in most food chains, all the organisms in a food chain are consumers.

ECOLOGICAL PYRAMIDS Anecological pyramid(alsotrophic pyramidorenergy pyramid) is a graphical representation designed to show thebiomassorbiomass productivityat eachtrophic levelin a givenecosystem. Biomassis the amount of living or organic matter present in an organism. Biomass pyramidsshow how much biomass is present in the organisms at each trophic level. Productivity pyramidsshow the production or turnover in biomass. Ecological pyramids begin with:producers > herbivores > carnivores that eat herbivores > carnivores that eat those carnivores > and so on... There are basically 3 types of ecological pyramids:Pyramid of biomass - shows the relationship between biomass and trophic level by quantifying the biomass present at each trophic level of anecological communityat a particular time. This type of pyramid may be also inverted.Pyramid of productivity - shows the production or turnover of biomass at each trophic level. Instead of showing a single snapshot in time,productivitypyramids show the flow ofenergythrough thefood chain. When an ecosystem is healthy, this graph produces a standardecological pyramid. This is because ***In order for the ecosystem to sustain itself, there must be more energy at lower trophic levels than there is at higher trophic levels.Pyramid of numbers - shows graphically the population of each level in a food chain.

1. All food chains must start with a (an) ___________ Consumer Food Producer Energy2. A food chain shows ___________ The amount of food in an ecosystem How organisms behave while eating How organisms are related with each other by the food they eat How organisms survive while eating inorganic matter3. The main difference between a food chain and a food web is that ___________ The food chain only follows linear monophagous pathways The food chain only follows complex polyphagous pathways4. Food chains are often used in ___________ Cosmetics Ecological modeling Ecosystem studies5. In a food chain, plants are good examples of ___________ Consumers Energy Producers Decomposers6. In a food chain, animals are good examples of ___________ Starch Producers Consumers Photosynthesis7. Suppose that we have a vegetarian animal which eats plants. We call this animal ___________ Producer Primary consumer Tertiary consumer Energizer8. In which of the following, did food chains have an important role? Ecological modeling Ecotoxicology studies Biochemical studies Engineering

9. Producers, such as ___________ use ___________ to synthesize starch Animals / Milk Plants / People Animals / Air Plants / Energy10. Length of food chains vary from ___________ One to Two levels Three to Eight or more levels Two to Six or more levels Three to Six or more levels11. Ecological pyramids are also known as ___________ (2 choices can be made) Desert pyramids Trophic pyramids Vital pyramids Energy pyramids12. An ecological pyramid shows the biomass or biomass productivity at ___________ First trophic level Each five trophic levels Each trophic level Last trophic level13. Biomass is ___________ The amount of organic matter in an organism The amount of inorganic matter in an organism The ecosystem in which animals live14. Food chains and ecological pyramids are almost the same as they ___________ Begin with a producer Begin with a tertiary consumer End with energy15. Productivity pyramids are different from biomass pyramids as they ___________ Convert biomass into mass Show the production or turnover in biomass Show how much biomass is present at each trophic level16. How many types of ecological pyramids are there? 5 3 417. Pyramids of biomass may differ from others because they can be ___________ Inverted Incomplete

18. It shows graphically the population of each level in a food chain. This sentence best describes a ___________ Pyramid of biomass Deep-Sea food chain Pyramid of numbers Three-level food chain19. In order for an ecosystem to sustain itself, there must be ___________ energy at ___________ trophic levels than there is at ___________ trophic levels. Less / Higher / Lower More / Higher / Lower More / Lower / Lower No / Higher / Lower20. A ___________ is produced only and only when an ecosystem is ___________ Pyramid of biomass / Healthy Standard ecological pyramid / Sick Food chain / Clean Standard ecological pyramid / Healthy