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Diversity of Life

Classification Based on Body Plan

Body Plans 5

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Maryland Science Content Standard

• Students will be able to provide examples and explain that organisms sorted into groups share similarities in external structures as well as similarities in internal anatomical structures and processes which can be used to infer the degree of relatedness among organisms

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• Students will be able to identify the ways to classify organisms based on their body plans.

• Title:Body Symmetry• Date: 04/18/23

Objective

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Warm-Up:

• How many equal parts can you divide each of the following into?

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Today Students Will…

• Engage their thinking of different organisms’ body plans by discussing different body plans

• Explain symmetry by discussing bilateral and radial symmetry.

• Explore body plans of different organisms using a website

• Evaluate their understanding of bilateral and radial symmetry by labeling the body plans of different organisms on a worksheet

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Body Plans: Weirdness!!

• What is the weirdest living thing you can think of?

• What is its body like?

• How many legs does it have?

• How many segments does it have?

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Body Plans

• Organisms are classified based on many different factors. One of the factors used to group organisms is the way their body is structured, or their body plan.

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What is symmetry?

• In math class we learn that symmetry is when we can cut an object into two equal and identical halves.

• Are humans symmetrical?

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Symmetry in Animals

• Comes in two types– Radial– Bilateral

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Bilateral Symmetry

• This is the human type of symmetry

• This is when one single straight line can be created between halves of an organism.

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Radial Symmetry

• Radial Symmetry is when more than one line can be drawn through the object. Each of these lines creates an identical and equal part.

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Explore Body Plans

• Read the information on the following link, and try the activity at the bottom of the page:

• Click Here!!!!

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Evaluate your understanding

• On your worksheet:– Define Symmetry– Compare and contrast Radial and Bilateral

symmetry– Identify the type of symmetry in each picture

by drawing the lines of symmetry.

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BCR: Answer the following question using your MSA Science Rubric.

• Why do you think scientists use body plans to group (classify) organisms?

• Include in your answer:– The different types of symmetry.– What kinds of organisms have each type of

symmetry?– How an organism’s body plan might relate to

its lifestyle.

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Conclusion - Extend your thinking

• Which type of symmetry is most common?– In plants?– In animals?– Which kinds of animals have each type of

symmetry?