Energy and Nutrient TransferFood 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 chainsFood chainsFood chainsFood chains
Food chains
Food Chains
Green plant
Plant eater
Meat eater
Producer
Herbivore
Carnivore
Producer
Primary consumer
Secondary consumer
Top carnivore Tertiary consumer
The direction of the arrow shows
the direction energy is passed
1. Food chains can be connected together to form food webs
2. If the population of one species in a food web changes it can affect many other species’ populations.
Food websFood websFood websFood webs
Food webs
Pyramids of numbers and Biomass
Objectives:*Draw describe and interpret pyramids of numbers and pyramids of biomass**Compare pyramids of numbers and pyramids of biomassH/W due in on 11/11Draw 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 & BiomassPyramid of Numbers & BiomassPyramid of Numbers & BiomassPyramid of Numbers & Biomass
Pyramid of Numbers & Biomass
TCSCPCP
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
Wasted EnergyWhenever 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 transferEnergy transferEnergy transferEnergy transfer
Energy transfer
2-5%
2-5% absorbed by leavesRest 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
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 CycleThe Carbon CycleThe Carbon CycleThe Carbon Cycle
The Carbon Cycle
Carbon dioxide levelsCarbon dioxide levelsCarbon dioxide levelsCarbon dioxide levels
Carbon dioxide levels
1
2 346
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 Cyclehttp://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 CycleThe Nitrogen CycleThe Nitrogen CycleThe Nitrogen Cycle
The Nitrogen Cycle