Download presentation
Presentation is loading. Please wait.
Published byMeagan Kennedy Modified over 9 years ago
1
Good Morning!!
2
Warm-up October 1 st Day 2 Create a food chain using the following organisms. What do your arrows represent?? Shrew HawkGrasshopper Homework Due: Food Chains & Webs packet
3
Warm-up October 1 st Day 2 Food Chain: Grasshopper Shrew Hawk The arrows show the flow of ENERGY!!
4
Activity Instructions You will play the role of a hawk, shrew, or grasshopper… 1. Grasshoppers get to collect food in their stomach (brown paper bag) while shrews and hawks watch their prey. 2. Shrews hunt their prey (grasshoppers). **When you catch your prey you get their stomach! 3. Hawks hunt shrews. Living shrews can still hunt grasshoppers until you get “eaten.”
5
Return to your seats… All living animals should count the contents of their stomachs. –Count & record # light colored cereal –Count & record # of dark colored cereal
6
Class Data PopulationLight Colored Cereal Dark Colored Cereal Grasshopper0 living Shrew10118 Hawk 1335 Hawk 28318
7
Class Data OrganismNumber Remaining Initial Population Grasshopper08 Shrew13 Hawk22
8
Oh no!! A pesticide! Farmers sprayed the crop that the grasshoppers were eating with a pesticide. All dark colored cereal represents this pesticide!
9
What does this mean?? All living shrews with half or more dark colored cereal are dead due to the pesticide! The hawk with the most dark colored cereal will live, BUT so much of the pesticide accumulated in your body that the eggs of you and your mate will have a very thin shell and will not hatch!
10
How do toxic substances enter a food chain?? Grasshopper Shrew Hawk
11
Biomagnification Biomagnification is the increase in concentration of a pollutant from one link in a food chain to another Can result in the accumulation of chemicals in species higher in the food chain.
12
Another Example DDT (dichlorodiphenyltrichloroethane) was applied to crops to control insect damage. In the early 1970s, it was discovered that DDT had entered the food chain. Fish ate insects sprayed with DDT. Hawks, eagles, and pelicans at the fish.
13
We thought DDT was a good things!
14
However… DDT became concentrated in the birds body’s and their egg shells became very thin. The weight of the adult bird would crush the eggs in the nesting process. This impacted the population of our national bird, the bald eagle!
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.