A provocative piece from a really great biology blogger on how the microscope "e" lab and learning all the parts of the microscope kills interest in biology. Instead, have students start by observing real, live, big things under a dissecting scope or a magnifying glass first.
A much smaller version of the diving reflex occurs in humans and is easy to demonstrate in the lab using a few Vernier sensors, a large bowl of cold water, or a cold pack on the face. When cold water (10°C or less) contacts the face, the diving reflex is elicited. Breathing is inhibited and heart rate decreases. This response is not observed during normal breath holding in air or when the face is placed in warm water. Heart rate will actually increase in these two conditions.
In Sponge Lab Biology's Build a Body students construct a human body system-by-system. To build a body students drag and drop into place the organs and bones of a human body. Each organ and bone is accompanied by a description of the purpose of that bone or organ. The systems that students can build in the Build a Body activity are the skeletal, digestive, respiratory, nervous, excretory, and circulatory systems.