Summary
Frog dissections are a classic biology lab. This lesson is best not only after students have had some gross anatomy but also when you trust students enough to let them use scalpels in the classroom.
Essential Question(s)
How are living organisms connected?
Snapshot
Engage
Students complete a modified Kick Me over the anatomical positions.
Explore
Students dissect a frog.
Explain
Students follow along as the teacher helps identify the parts.
Extend
Students do research on different body parts and homology to humans.
Evaluate
Students participate in a Four Corners debate about frogs' homology to humans.
Materials
Copied Kick Me labels; enough so each lab group has one
Lab Handouts for dissection; enough for each student
Frogs for dissection; see resources for shopping options
scalpels for dissection
Dissection pans
Gloves
Safety googles
Dissection pins
Document camera or projecting dissection microscope
Copies of research tables; enough for each student
Student devices with internet access
4 Corners signs
Engage
Print out enough of the Kick Me labels so that each group can have a set of words (it's three sets per page). The students will be doing a modified Kick Me. That is because they will not put one word on each other's back. Rather, each lab team will race to put the anatomical positions correctly on one of their lab group members.
Explore
Have students stay in their groups from the Engage activity. Direct them to put on gloves and goggles. Just remember that safety needs to be the first priority.
Pass out a lab handout to each student and pass out a frog to each student. The handout has step-by-step instructions of how to dissect the frog, so try to allow them some autonomy to follow the instructions without turning it into a whole-group dissection.
As the students work through their dissections, walk around and help as needed.
Explain
After the students are done with their dissections, pick a particularly good dissection (either from the students or one that you have cut open yourself), and put it either under a document camera or a projected dissection scope (so all the students in the class can see it). Guide the students by pointing out the different organs to clear up any questions the students had, especially with hard to identify organs.
Extend
Once you feel that the students can identify the organs on their own, pass out a copy of the Frog Research work page to each student as well as devices with internet access. Have the students, still in their lab groups, fill out the tables and research the homology between frogs and humans for each organ.
Evaluate
Students will do a Four Corners over the statement "Frogs and humans are anatomically similar." The four corners of the classroom should have one sign in each: one corner should say "Agree," one should say "Somewhat Agree," one should say "Somewhat Disagree," and the last one should say "Disagree." Direct students to go to the corner they feel most corresponds to the statement.
Once students have picked their corners, have each opinion group create an argument to defend their choice. Have each group share their argument and allow students to change positions if the argument is compelling enough or helped them change their mind.
When all the arguments are done, tell the students to sit down and write a two-sentence Exit Ticket of what they finally decided the answer to the statement is and why they feel this way.
Resources
K20 Center. (n.d.). Kick Me. Strategies. https://learn.k20center.ou.edu/strategy/d9908066f654727934df7bf4f505b77c
Frogs for dissection: http://www.carolina.com/preserved-frogs-bullfrogs-necturus/carolinas-perfect-solution-preserved-frogs-x-jumbo-4-5-in/FAM_227444.pr
K20 Center. (n.d.). Four Corners. Strategies. https://learn.k20center.ou.edu/strategy/d9908066f654727934df7bf4f5064550
K20 Center. (n.d.). Bell Ringers and Exit Tickets. Strategies. https://learn.k20center.ou.edu/strategy/d9908066f654727934df7bf4f505d6f2