April 29th, 2013

• Warm - Up:1) What is the difference between a chain and a web?

2) In 2 minutes, write a definition for each, and compare what you wrote with the person sitting next to you.

April 29th, 2013• The following slides are numbered 1-24.

For today’s assignment:

Write the number and an answer to the question (don’t write the question)

How do biotic compare to abiotic?• All living parts of

a habitat– Plants– Animals– Bacteria

• All non-living parts of a habitat- Water- Soil- Rocks- Fire

1 Factors in an ecosystem:

Are these animals biotic or abiotic factors?

2

Biotic or Abiotic?3

Biotic or Abiotic?4

Biotic or Abiotic?5

Biotic or Abiotic?6

Why are plants called producers?

• The ultimate source of life is the sun

• Plants use the sun’s energy to make food in a process called photosynthesis

• Examples- cactus, trees, algae, phytoplankton

7

energy +CO2 +H2O = sugar + O2

“plant food”

What are consumers?• Herbivores-

plant-eaters

• Carnivores- meat-eaters

• Omnivores- eat plants & meat

• Scavengers – a carnivore that feeds on body of dead organism

• Decomposers- organisms that break down wastes & dead organisms & return materials to ecosystem

8

What is a food chain?

• A sequence that links a species by its feeding relationships

• Example: grass cottontail hawk

9

What is a food web?• Model that shows

the network of feeding relationships, and the flow of energy in the ecosystem

• Food webs show all the connected food chains

10

11 What do decomposers eat?

April 30th, 2013• Today’s Warm-Up Draw two food chains

for two different carnivores.AGENDA• Any presentations?• The following slides are numbered 13-24. For

today’s assignment:Write the number and an answer to the question (don’t write the question)

• QUIZ using ecosystems poster

What is an energy pyramid?• Diagram that

compares energy used by producers, primary consumers, and secondary consumers

• Each level is a called a trophic level, and it is occupied by an organism

12

What happens at each feeding level?• Energy is lost as it flows UP a level• Carnivores are at the top• Herbivores are at the 2nd level• Producers are at the bottom

13

14 Why are bears at the top?

15 Why are there so many producers?

Reef SharkThe reef shark gets energy by

eating parrotfish and triggerfish.

16 Is this a producer or a consumer?

TriggerfishThe triggerfish gets energy by

eating shrimp.

17 Producer or Consumer?

ShrimpThe shrimp gets energy by eating

phytoplankton.

18 Producer or Consumer?

PhytoplanktonPhytoplankton get energy from

the sun.

19 Producer or Consumer?

Sea SpongeSea sponge gets energy by eating

zooplankton.

20 Producer or Consumer?

ZooplanktonZooplankton get energy by eating

phytoplankton.

21 Producer or Consumer?

ParrotfishThe parrotfish gets energy by

eating algae

22 Producer or Consumer?

Sea Turtle

The sea turtle gets energy by eating algae.

23 Producer or Consumer?

Algae

Algae get their energy from the sun.

24 Producer or Consumer?

food chain compared to food web• It moves like a

cycle• It has few

organisms– Plant to animal– Animal to

animal

• It goes in many directions

• It has many organisms- Plant to

animal 1, animal 2, …

Compare:

Both show what organisms eat, and the flow of energy

End.

April 30th, 2013• What features enable fish to survive

underwater? (Give two examples)• Why do snakes live so well in the desert?• Why do mosquitoes need people?

• For today’s assignment:Write the number and an answer to

the question (don’t write the question)