Name:                            Robin L. Lewis

Subject:                         Biology I-Ecology (Day2)

Period:                           3^rd

Approximate Time:       50 minutes

Objectives:

The student will…

1.  Differentiate between food chains and food webs. (MSF Biology I  7d)

2.  Analyze the transfer of energy in an ecosystem through food chains and food webs. (MSF Biology I  7d)

Materials:

White board, markers, eraser, pens, pencils, paper, white paper, markers, and color pencils

Set:

Review your food chain from yesterday.  Circle the producer at the beginning of your food chain.  Since the thing you circled is an autotroph, where does it energy come from?  How is it passed through an ecosystem? Today, we going to differentiate between food chains and food webs, and analyze the transfer of energy in an ecosystem through food chains, food webs, and food pyramids.

Procedures:

1. Bellwork: Quiz on levels of organization.
2. Collect papers
3. Bellwork Review.
4. See Set.
5. Answer questions from the set.
   1. Energy comes from the sun.
   2. Passed when a consumer eats a producer.
6. So far we’ve talked about consumers and producers or autotrophs and heterotrophs, now we will introduce 2 other types of consumer that is vital to an ecosystem-decomposers and ditritvores.
   1. Decomposers-break down dead organisms

                                         i.    Ex. Bacteria, fungi

2. Ditritivores-break down detritus and return elements to the soil.

                                         i.    Ex. Earthworms

7.    Introduce food chain-single pathway of feeding relationships among organisms in an ecosystem.  Draw a food chain on the board.  Grass, mouse, snake, hawk.  Draw a line between each word, but now an arrow.  Have students reflect on the last energy statement, then question which ways should the arrow go.  (arrow points toward the organism that was feeding)  Have the students revisit their last meal info and draw a food web from that information.

a.    Food Webs-just like food chains except they show interrelated food chains.

                                         i.    Incorporate a rabbit, a tree, grasshopper, lizard, and a fox

b.    Each consumer is labeled in the order in which they received energy: mouse-1^st, snake-2^nd, and hawk-3^rd.

8.    Discuss energy flow.

a.    Energy is transferred when one organism eats another organism.  In food chains/webs energy only flows in one direction.

b.    Every step in the food web represents a trophic level.

c.    Trophic levels show how many times energy has been transferred.

d.    Energy pyramid-shows the way that energy is transferred to each trophic level.

                                         i.    Only 10% is transferred to each level.

                                        ii.    Have students equate percent and money.  Producers have $100….4^th level=a penny

9.    Individual practice. Pass out white paper, markers, and color pencils.  Students will create a food web using at least 6 organisms in their local ecosystem.  Label producers, 1^st, 2^nd, & 3^rd level consumers.  Encourage students to be creative.  They can draw the animals or write the words.

Closure:

Today we learned how to differentiate between food chains and food webs, and how to analyze the transfer of energy in an ecosystem through food chains and food webs.

Review students.  What is an energy pyramid and what does it show?  What is always at the start of a food chain?  Where does all of the energy for life come from?  What percent of energy is transferred from one trophic level to the next?

Tomorrow we will explore other types of pyramids that show some form of energy transfer.

Assessment/Evaluation:

Objectives:

·      TSW Differentiate between food chains and food webs.

·      Analyze the transfer of energy in an ecosystem through food chains and food webs.

1. Informal

                                         i.    Teacher observation (M) of the student’s practice in their notes.

2. Formal

                                         i.    Student will draw a food chain and a food web that shows the transfer of energy from producer to consumer (C) to be graded (M) and recorded in the gradebook (D).