Dissection 1

Dissection: Measuring and Comparing

Subject Area	Dissection: Measuring and Comparing
Age or Grade	8th grade
Estimated Length	Approx. 90 minutes
Prerequisite knowledge/skills	Basic measuring skills; understanding of scale drawing/ratio; ability to make scale drawings
Description of New Content	1. A map is a representation of a place or area. 2. Scale is the size relationship between a representation and an actual object. 3. Scale models help people understand relative size and understand relationships when actual distances are too large or small to deal with. 3. Allometry is the relationship between size and shape. 4. Allometry rules enable predictions about the size of objects and organisms with similar shapes.
Goals	Students will learn basic anatomy terms. Students will be able to draw animals to scale. Students will use 2-D models (drawings) to locate organs in an actual animal.
Materials Needed	Clams, earthworms, and frogs for dissection (wardsci.com), dissecting trays, gloves, goggles, dissecting tools (pins, scissors, scalpels), worksheets (Clam, Frog, Earthworm)
Procedure	Opener Show students the animals they will observe in detail during the class period. Talk about some basic life history traits of the animals (e.g. habitat, food source, predators). Talk about how/why the animals diedand what the students will gain from this dissectionlesson (see wardsci.com FAQ webpage). Discuss safety (gloves and goggles required; hand washing is a must) Procedure: 1. Discuss ethics with students, reminding them to respect the value of life. 2. Set up separate dissection stations- clam/earthworm and frog. 3. Tell students to complete the worksheet and pay attention to similarities and differences between the animals. Closure Review worksheet answers by calling on students.
Evaluation	Grade worksheets, check scale drawings. Have students re-do drawings if necessary.
Extensions	Use this lesson as the start of a unit on the classification of life, animal biology, ecosystem science, etc.
References