Seventh grade: Mystery of the Dead Hemlock Tree

In this lab students will:

• Create a mixture and make observations about its properties to determine if a chemical reaction has occurred.
• Learn techniques to micropipette and measure small quantities of liquids
• Discuss the effects of resource availability on the hemlock ecosystem
• Discover and identify interactions (competitive, predatory, and mutually beneficial) between organisms in the hemlock ecosystem
• Perform gel electrophoresis to compare DNA from known pests to an unknown tree killer (scientists use this method to separate parts of a mixture)
• Investigate how changes to the hemlock ecosystem affect populations and biodiversity.

Standards:

• 7-PS1-2. Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
• 7-LS2-1. Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
• 7-LS2-2. Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems.
• 7-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
• 7-LS2-5. Evaluate competing design solutions for maintaining biodiversity and ecosystem services.

Typical Schedule*:

*Schedule can be adjusted to meet your school’s needs
**If you have more than 64 students, see large group schedule

Typical Large Group Schedule*:

*Schedule can be adjusted to meet your school’s needs
**B group participates in another campus activity; school chaperones arrange
***A group participates in another campus activity; school chaperones arrange