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These activities remind me of the importance of starting any unit of study in biology with a kinesthetic experience.

The two point touch activity is one I have used sucessfully with Grade 7 bio students using a clay disk with dissecting pins. I like better the calipers as the tool. Students enjoy using tools that appear scientific, and the callipers are condusive to quantitative recording in their lab notebooks. Today, we examined the difference in sensory experience as the tester moves the calliper from middle of the lower inner arm to the wrist to the palm to the finger to finger tip. This would be a tighter experiment for the students than the more scattered approach I have used in the past. Once they appreciate the difference degrees of sensation in the arm, we could extend the activity to other parts of the body such as lips because of the discussion we could have about the adaptive advantage of having more sensitive areas of the body.

The activity with hot and cold touch on the arm would be difficult for my Grade 7 bio students. They would not be careful enough to avoid dripping water all over the arm to be able to get a clear diagram of temperature drawn on the arm with the different colors of pens. They would be able to record the sensation of temperatures as the tester moves along the inner arm from right below the elbow joint to the wrist to the palm to the finger tips.

The jelly bean activity to exemplify the cooperation among smell, taste, and vision would be very well received by Grade 7 bio students. I will continue to use the test comparing a slice of raw apple and a slice of raw bakig potato. Both are grainy in texture, and without sight and smell, "taste" the same. I would start with the potato-apple example which is very stark and then go to the jellybean example which is more subtle and more fun. The comparison of different types of chocolate would be effective with older high school or college age students.