Pre-Lab: Comparing Invertebrate Body Plans
Problem What characteristics can be used to classify invertebrates?
Materials compound microscope; prepared slides of cnidarian, roundworm, and earthworm cross sections; red, blue, and yellow colored pencils
Lab Manual Chapter 25 Lab
Skills Focus Observe, Classify, Compare and Contrast
Connect to the All members of Kingdom Animalia share a set of characteristics that define them as animals. However, the diversity within the kingdom is vast. For example, some animals have a backbone, but many do not. Some animals have radial symmetry, but many do not. In this lab, you will use preserved cross sections to compare the body plans of three invertebrates. You will pay particular attention to germ layers and body cavities.
Review Describe three characteristics that all animals share.
Review What are the three germ layers, and what structures do they give rise to?
Explain What is the function of a body cavity?
Preview the procedure in the lab manual.
Compare and Contrast Which two features of animal body plans will you be comparing in this lab?
Apply Concepts Where will you look for tissue that formed from the ectoderm layer?
Infer Is a hydra smaller than, larger than, or about the same size as an earthworm? Base your answer on the procedure in this lab.
Visit Chapter 25 online to test yourself on chapter content and to find activities to help you learn.
Untamed Science Video Learn how scientists determine that an organism is an animal as the Untamed Science crew visits a research facility on Coconut Island.
InterActive Art Learn how a sponge performs its life processes while staying still.
Art in Motion View an animation that shows the differences in early development in protostomes and deuterostomes.
Art Review Review your understanding of body symmetry with this drag-and-drop activity.
Data Analysis Compare Trichoplax to other animals to get an appreciation of the difficulty of classifying animals.