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Science_Lab_Yellow / Lesson 9: How Are Populations Connected?

Populations are Connected
What will we be learning today?


  • In this lesson, we are going to learn all about how populations are connected.


How Are Populations Connected?


  • What would happen if farmers used powerful insecticides to kill pests? What might happen if these pesticides also killed some harmless ants?

  • Ants live in the same habitat as Texas horned lizards. Because the lizards eat ants, changes in the ant population may tell a lot about the future of the lizards.


  • In the food chain, the relationship doesn't stop there. Birds of prey, such as hawks, feed on the lizards.

  • What happens to the ants will also affect the lives of these birds. A change in one population affects all the other organisms in that food chain


  • Animals may adapt to changes in their habitats. A varied diet can be useful. Texas horned lizards eat mainly ants. They also eat other insects such as grasshoppers.

  • If the ant population decreases, the lizards can feed on grasshoppers instead. This changes the number of grasshoppers in a community, however.

  • The other organisms that eat grasshoppers will be affected, too. A change in the ant population affects more than just a food chain. It affects all of the organisms in a food web


  • Food chains and food webs help scientists predict how communities will be affected by change


  • Let's Review What We Learned Today!


    • Now complete the worksheet!