Download presentation
Presentation is loading. Please wait.
1
Energy and Ecology
2
Ecosystem Components Producers Basis of an ecosystem’s energy
Autotrophs: perform photosynthesis to make sugars Chemotrophs: Bacteria which use minerals from deep-sea vents to make energy Consumers Heterotrophs: Consumes others for energy Omnivores, herbivores, carnivores, decomposers, detritivores
3
4 kcal 40 kcal 400 kcal 4000 kcal 40,000 kcal
Trophic Levels 4 kcal 40 kcal Defined: Feeding level of an ecosystem Trophic levels consist of producers, consumers, and decomposers ~10% of energy is passed to the next level ~90% used by the organism or lost as heat Food chains contain few trophic levels 400 kcal 4000 kcal 40,000 kcal
4
Food Chains 1st trophic level = Producers
Autotrophs (perform photosynthesis) Bottom of food chain Ex: Plants, algae, cyanobacteria
5
Food Chains 2nd trophic level = Primary consumers Feed on producers
Herbivores (plant eaters)
6
Food Chains 3rd trophic level = Secondary consumers
Feed on primary consumers Omnivores and carnivores
7
Food Chains 4th trophic level = Tertiary consumers
Feed on secondary consumers Omnivores and carnivores consumers
8
Food Chains 5th trophic level = Quaternary consumers
Feed on Tertiary consumers Omnivores and carnivores consumers
9
What’s wrong with this food chain?
The arrows are pointing the wrong direction. This implies that the plant eats the grasshopper.
10
What’s wrong with this food chain?
The arrows are pointing the wrong direction. This implies that the grasshopper eats the mouse.
11
What’s wrong with this food chain?
The arrows are pointing the wrong direction. This implies that the mouse eats the snake.
12
What’s wrong with this food chain?
The arrows are pointing the wrong direction. This implies that the snake eats the hawk.
13
Much better… The arrows show the direction that energy is passed up the food chain.
14
Label the tropic levels in this energy pyramid
Choices: Primary consumer Decomposer Tertiary consumer Secondary consumer tertiary consumer secondary consumer primary consumer producer
15
Decomposers Rarely shown on food chains Quaternary consumer
Teriary consumer Secondary consumer Primary consumer producer
16
Decomposers Rarely shown on food chains
Teriary consumer Rarely shown on food chains Feed on any trophic level when it dies Secondary consumer Primary consumer producer Decomposer
17
Decomposers Rarely shown on food chains
Feed on any trophic level when it dies Detritivores: Feed/ingest dead matter Decomposers: secrete enzymes to break down dead matter and then absorb the nutrients
18
Defined: Group of interrelated food chains
Webs Defined: Group of interrelated food chains This food web is made from dozens of food chains Arrows show direction energy (nutrients) travel
19
Highlight a food chain from this food web
Highlight a food chain from this food web. Then label each trophic level. Tertiary consumer Secondary consumer Primary consumer producer
20
Highlight a food chain from this food web
Highlight a food chain from this food web. Then label each trophic level. Quaternary consumer Tertiary consumer Secondary consumer Primary consumer producer
21
What could happen if the grasshoppers die out due to pesticide use?
Owl death (less blue jays to eat) Blue jay death (less spiders to eat) Spider death (no more grasshoppers to eat) Squirrel increase (less owls hunting them)
22
YouTube Food Chain Video
23
Review How many trophic levels are in the following food chain?
Apple tree Worms Blue Jay Owl If the tree in the example above makes 15,000 calories of energy from photosynthesis, how much energy is available for each other trophic level? In the food chain above, which is the producer? In the food chain above, which is the primary consumer? In the food chain above, which is the tertiary consumer? Which level consumer are herbivores known as? What is the lowest consumer level possible for a carnivore? Examine the food web on slide #10. Find a complete food chain that is 6 trophic levels from start to finish.
Similar presentations
© 2025 SlidePlayer.com Inc.
All rights reserved.