Photoautotrophs光能自养 Chemoautotrophs化能自养 Because these organisms use light as their energy source,they are called photoautotrophs. Chemoautotrophs are autotrophs that obtain their energy not from sunlight but from certain specific chemical reactions involving only inorganic substrates. 21
21 Photoautotrophs 光能自养 Chemoautotrophs 化能自养 • Because these organisms use light as their energy source, they are called photoautotrophs. • Chemoautotrophs are autotrophs that obtain their energy not from sunlight but from certain specific chemical reactions involving only inorganic substrates
Food Chains A food chain is the path of food from a given final consumer back to a producer.For instance,a typical food chain in a field ecosystem might be: grass->grasshopper->mouse->snake->hawk 22
22 Food Chains A food chain is the path of food from a given final consumer back to a producer. For instance, a typical food chain in a field ecosystem might be: grass -> grasshopper -> mouse -> snake -> hawk
We typically list a food chain from producer on the left (or at the bottom)to final consumer on the right (or at the top). Food chains and food webs are representations of the predator-prey relationships between species within an ecosystem or habitat 23
23 We typically list a food chain from producer on the left (or at the bottom) to final consumer on the right (or at the top). Food chains and food webs are representations of the predator-prey relationships between species within an ecosystem or habitat
Each organism in a food web or chain represents a feeding step,or a "trophic level". Sun Food Chain Producer Tertiary Primary Secondary Consumer Consumer Consumer Grasshopper Snake Grass Hawk Nutrients Decomposer Water Fungi
24 Each organism in a food web or chain represents a feeding step, or a “trophic level
A food web shows all the possible eating relationships in a community. 25
25 A food web shows all the possible eating relationships in a community