Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
+ Topic 5.2 https://www.youtube.com/watch?v=joZ1EsA5_NY Ecosystems rely on energy transfer + Introduction An ecosystem is: A self-sufficient system consisting of a community of interacting organisms and the abiotic factors of their habitat What does self-sufficient mean? The organisms are interdependent and ALL rely on Producers Producers are autotrophs: what does this mean? They are able to produce their own food, they convert inorganic substances to organic substances. + What are the 2 types of autotrophs- give examples: Photosynthetic: plants, phytoplankton and some bacteria Chemosynthetic: some bacteria: synthesis organic molecules using energy released from exergonic reactions When might chemosynthesis be useful? Deep in the ocean where there is not enough light Is a link between productivity and biodiversity? Usually a direct correlation, but not always (exception - when eutrophication occurs) + Energy flow through the ecosystem + Feeding relationships grass grasshopper frog snake hawk Give examples of the following terms from the food chain above Autotroph, heterotroph, producer, consumer, prey, predator, carnivore, omnivore, herbivore, trophic level + Recycling What They ingest small pieces of dead plant or animal or waste like leaves, antlers, skin. Earthworms, woodlice, freshwater shrimps What are detritivores? Give examples. are decomposers ? Give examples. They breakdown dead organic material or waste by living on their food- releasing enzymes which digest externally and then absorb the breakdown products Bacteria and Fungi + Decomposers and detritivores What niche do they have in an ecosystem? They are important as they recycle organic compounds by breaking them down into small, inorganic compounds which can be used by producers. Checkpoint the blanks 5.4: Ecology definitions fill in + Activity 5.7 Constructing Food Webs + Activity 5.7 Constructing Food Webs + Photosynthesis converts light energy into chemical energy. How much of the light energy available to plants is actually converted into chemical energy? Very little estimated 5% + Energy Transfer What happens to the rest of the light energy? Is reflected Is used in evaporating water- transpiration Is transmitted through the leaf Only about 40% of light hitting a leaf gets absorbed by the chloroplast What happens to the 40% which is absorbed? some is converted into organic molecules in photosynthesis some is lost in the process of photosynthesis. Why? It is not 100% efficient and light may not be the limiting factor + Energy Flow through a food chain The flow of energy from one trophic level to another is not 100% efficient either. Usually <10% of the energy from producers is used to produce biomass in primary consumers. Why? Some parts of the plants don’t get eaten, e.g. roots, some are indigestible and pass out (egested) in faeces (cellulose for example),or lost in urine some energy used in respiration to provide energy to move, stay warm, active transport etc. + Energy Transfer 1. The transfer of energy from herbivores to carnivores is MORE efficient no cellulose, more protein= more digestible, more parts of the organism are eaten Law of conservation of energy: energy can not be created or destroyed, it can just be converted /transferred. energy entering = energy lost + the trophic level in respiration page 29. Q 5.21 energy lost + in faeces + urine energy in new biomass + Energy flow through an ecosystem + Productivity Define GPP: gross primary productivity the rate at which energy is converted into organic molecules in an ecosystem measured in kJ or MJ per m2 or ha per year (megajoule= 1 million joules. UNITS ARE IMPORTANT IN THE DEFINITION. Calculate the percentage efficiency of photosynthesis: (GPP/light energy striking the plant) x 100 What happens to the carbohydrates produced during photosynthesis? Respiration, or building other organic molecules, proteins etc Define biomass. The amount of living (organic) material present, it is produced by the organism and does not include water + Productivity Define NPP: net primary productivity the rate at which energy is transferred into the organic molecules that make up new plant biomass is called net primary productivity (NPP). What is the relationship between NPP and GPP? NPP = GPP – R + Net primary productivity terrestrial Many factors influence primary productivity rates, but the most important on land are temperature and water availability. + Ocean net primary productivity In contrast to land, where vascular plants carry out most primary production, most primary production in the oceans is done by microscopic algae. + Pyramids of Energy What does each bar represent? Why are food chains rarely more than 5 organisms? Since energy transfer from one trophic level to another is so inefficient, food chains rarely have more than 5 organisms + Activity 5.08 Energy Flow in a Ecosystem Q 1-read the question. Which letter represents the energy available to the bullock? C (3056) Which represents the energy used to make its new biomass? P (125) What happened to the rest of the energy? Egested or excreted or used in respiration. How efficient was the energy transfer from the producer to this primary consumer? P/C * 100% Complete Q 1 + Activity 5.08 Energy Flow in a Ecosystem A 1000 units falls on the plant per unit time. F 400 units are absorbed by chloroplasts. B 500 units are of wavelengths not used in photosynthesis. G 308 units are used in the reactions of photosynthesis. This energy is lost to the environment. C 500 units have wavelengths in the range 400– 700 nm so it can be used in photosynthesis. H 92 units are converted to carbohydrate in photosynthesis (gross primary production). D 50 units available for photosynthesis are reflected. I 55 units become plant biomass (net primary production). E 50 units available for photosynthesis pass straight through the plant. J 37 units are released in cell respiration in the mitochondria. This energy is lost to the environment. + Activity 5.08 Energy Flow in a Ecosystem +