Presentation on theme: "Energy and Nutrient Transfer Food chains and Food webs Objectives: *Describe a food chain and each feeding stage in it **Distinguish between a food chain."— Presentation transcript:
Energy and Nutrient Transfer Food chains and Food webs Objectives: *Describe a food chain and each feeding stage in it **Distinguish between a food chain and a food web
USING YOUR OWN KNOWLEDGE AND THE TEXT BOOK FIND THE MEANINGS OF THE FOLLOWING WORDS: COMMUNITY, POPULATION,
1.Food chains show which organisms eat other organisms 2.Food chains always begin with producers (green plants) which provide food for consumers 3.The energy for the producer always come from the Sun Food chains
Food Chains Green plant Plant eater Meat eater Producer Herbivore Carnivore Producer Primary consumer Secondary consumer Top carnivoreTertiary consumer The direction of the arrow shows the direction energy is passed
Pyramids of numbers and Biomass Objectives: *Draw describe and interpret pyramids of numbers and pyramids of biomass **Compare pyramids of numbers and pyramids of biomass H/W due in on 11/11 Draw two pyramids of numbers with different shapes. Explain their shapes.
1.A pyramid of numbers shows the relative number of organisms at each trophic level of a food chain but do not take the size of the organisms at each trophic level 2.A pyramid of biomass shows the amount of mass (or energy) at each trophic level of a food chain but do not indicate the rate of growth of the organism. Biomass varies with seasons. 3.Energy is lost at each stage of a food chain Pyramid of Numbers & Biomass TC SC PC P No. of individual decreases
Shortening the Food chain Objectives: *Explain energy losses between trophic levels in food chains **Explain the increased efficiency in supplying green plants as human food compared to feeding crop plants to animals
Energy Pyramids 67 1600 14000 87000 Water weeds – tadpoles – small fish - pike
Wasted Energy Whenever energy is transferred along a food chain, a lot of the energy is wasted at each stage in the food chain. For example when a leaf is eaten by a caterpillar, not all of the energy in the leaf is passed to the caterpillar. Energy wasted(90%) when leaf eaten by a caterpillar Energy transferred (10%)when leaf eaten by a caterpillar
Energy transfer 2-5% 2-5% absorbed by leaves Rest reflected back
Explain the increased efficiency in supplying green plants as human food compared to feeding crop plants to animals.
Nutrient Cycles Objectives: *Describe the role of bacteria and fungi in decomposition **Describe the different stages of water cycle
consumers decomposers Nutrients in environment producers
1.Burning fuels, respiration, acid rain on certain rocks (e.g. limestone) release carbon dioxide into the atmosphere 2.Oceans and plant photosynthesis remove carbon dioxide from the atmosphere The Carbon Cycle
1 23 4 6 5 Animal Respiration Bacterial Respiration Atmospheric carbon dioxide Plant Respiration Combustion Photosynthesis Animals Dead organisms Green plants Wood, peat, oil and coal The Carbon Cycle 1.Copy this diagram out adding pictures and as many equations as you can. 2.Why are microbes so important in the recycling of carbon? 3.Why are plants so important in the recycling of carbon? 4.In which four ways are carbon atoms returned to the atmosphere as carbon dioxide? 5.Which of the numbered arrow has changed most in the last 50 years?
Water Cycle http://www.educationalrap.com/song/water- cycle.html
The Nitrogen cycle Objectives: *Describe the roles of microorganisms in the nitrogen cycle **Describe the absorption of nitrate ions by plants and their use in making proteins that enter food chains http://www.clickbiology.com/video-nitrogen-cycle/
1.Plants and animals need proteins for growth and repair 2.Animals eat plants for their supply of protein 3.Plants absorb nitrates from the soil for their supply 4.Nitrates in the soil can be replaced by crop rotation, using fertilisers or, occasionally, by lightning The Nitrogen Cycle