Keith Wilhelmi's Self-Paced Frog Dissection Guide
It is understandable that some students will feel uncomfortable dissecting a frog, either over concern for animals having been killed for their lab work, or simply the "yuk" factor. However, dissecting offers a unique experience well worth overcoming these objections.
It is important to keep in mind that nearly all wild frogs have rather short lives and eventually serve as food for other organisms such as birds, fish, snakes, or humans. While we should not take the death of frogs used for dissection lightly, I believe that using frogs' bodies for educational purposes is as worthwhile as having them serve as food. In addition, the evidence is strong that bullfrogs are now an invasive species in much of North America.
This activity provides a good overview of the organ systems of a complex living thing - one with many similarities to our own. This reinforces students' respect for their own bodies and the choices they make regarding what they eat and drink and what drugs they might introduce into their amazingly complex bodies! While science has come a long way, we continue to be very limited in our ability to fully repair or replace most parts!
Learning and remembering are more effective when we use more of our senses in the process. During the dissection process the brain receives information from the eyes and ears, the muscles in the hands, the touch-sensitive nerves in the fingers, and even the smell receptors inside the nose! It is not surprising that some surgeons credit their middle or high school dissection labs for awakening them to their life's passion! Watching a video or even using a computer to "actively" take part in a virtual dissection experience will never match the real thing.
Dissecting a frog also reinforces the understanding of ecology, classification, and evolution. Students will notice many adaptations which allow frogs to survive in specific habitats and to fill certain niches. They will also observe some of the traits the frog shares with its predecessors and descendants.
Most students find this experience to be less "gross" than they anticipated. The frogs have been soaked in a mildly odorous preservative to assure that they are germ free, and while a small amount of this watery preservative may be released as the organs are exposed, liquid blood is not seen during dissection. Only a small amount of dark coagulated blood will be visible inside the heart.