Lesson Plan : Deadly Links

Teacher Name:
 Miss Montgomery ST
 Grade 3

 Food Chains, Changes in Food Chains
 pesticide- a chemical preparation for destroying plant, fungal, or animal pests insecticide- a substance or preparation used for killing insects herbicide- a substance or preparation for killing plants, esp. weeds food chain- the chain from a food source to the ultimate consumer accumulate- to gather or collect, often in gradual degrees; heap up toxic- acting as or having the effect of a poison chemicals- a substance produced by or used in a chemical process organic- characteristic of, pertaining to, or derived from living organisms inorganic- not having the structure or organization characteristic of living bodies
 Students will be able to 1) give examples of ways in which pesticides enter food chains and 2) describe possible consequences of pesticides entering food chains.
 TEKS SCIENCE GRADE 3 (3) Scientific processes. The student knows that information, critical thinking, and scientific problem solving are used in making decisions. The student is expected to:(A) analyze, review, and critique scientific explanations, including hypotheses and theories, as to their strengths and weaknesses using scientific evidence and information (8) Science concepts. The student knows that living organisms need food, water, light, air, a way to dispose of waste, and an environment in which to live. The student is expected to (C) describe environmental changes in which some organisms would thrive, become ill, or perish.
 one inch paper squares 30 pieces per student is recommended in a proportion of two-thirds white to one-third colored pieces one paper bag per grasshopper (about 15)
 Tell the students that this is an activity about "food chains". If they are not familiar with the term, spend time in establishing a definition.
 Divide the students into three groups. 1) Hawks 2) Shrews 3) Grasshoppers Work with approximately three times as many shrews as hawks, and three times as many grasshoppers as shrews. Optional: Have grasshoppers, hawks, and shrews labelled so they can be identified. Hand each grasshopper a small paper bag. The container is to represent the stomach of whatever animal is holding it. Distribute "food pieces" (small white/ colored pieces) in an open space
 Give the students the instructions: The grasshoppers are the first to go looking for food. The hawks and shrews are to sit quietly on the sidelines watching the grasshoppers: after all the hawks and shrews are predators, and are watching their prey! At a given signal, the grasshoppers are allowed to enter the area to collect food and place food in their stomachs. The grasshoppers have to move quickly to gather food. At the end of 30 seconds, the grasshoppers are to stop collecting food. The Shrews are now allowed to hunt the grasshoppers. The hawks are still on the sidelines quietly watching the activity. The amount of time available to the shrews to hunt grasshoppers should take into account the size area you are working in. Four minutes in a wide open space should be enough. Any grasshopper caught by a shrew must give its stomach to the shrew and sit quietly.
 This can be done in the classroom if bad weather occurs, with less movement and noise.
Checking For Understanding:
 Review questions using vocabulary.
 Talk with the students about what they just experienced in the activity. Ask them for their observations about how the food chain seems to work, and how toxic substances can enter the food chain, with a variety of results.
 Discuss the food chain as it relates to hawks, shrews, and grasshoppers. Give examples of other food chains in your habitat. Give three examples of ways in which pesticides could enter a food chain. Discuss two possible consequences of pesticides enter the food chain for each of the examples above.
Teacher Reflections:

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