Most of the organisms with which we are familiar, including humans, started with a sperm and an egg. One such organism, the sea urchin, has sperm and eggs remarkably similar to our own. Today we will study the living cells of the sea urchin performing the early stages of development. Ask and answer questions while introducing the model to insure active participation and check for understanding. Students fertilize eggs under the microscope, using gametes collected by the teacher.
Students draw and describe the stages of development observed.
Students write up their lab reports and answer implication questions .