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INSTRUCTOR(S)

DATE(S)

OBJECTIVE: Having finished lessons on mitosis and meiosis, the student shall demonstrate their ability to make microscopic observations and comparisons of the adaptations of the gametes of the sea urchin by writing a comprehensive lab report and answering the implications questions.

PURPOSE: This lab is designed to provide students with a laboratory experience with sea urchins in which they will observe gametes and practice microscope skills. After making these observations, students will use these gametes to observe fertilization and development of the sea urchin.

SET: 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.

INPUT MODEL: 1) relative sizes of microscopic objects 2) comparison of humans and sea urchins 3) injection of sea urchins to induce spawning 4) collection of gametes 5) some things to look for in egg and sperm STRUCTURED PRACTICE: Ask and answer questions while introducing the model to insure active participation and check understanding.

GUIDED PRACTICE: Students study eggs and sperm under their microscopes, using the gametes collected by the teacher. Students will make careful drawings of their observations.

CLOSURE: How does the design of sperm and egg insure their contribution to the continuation of the species, genetically, biochemically, and structurally?

INDEPENDENT PRACTICE: Students write up their lab reports and answer implication questions.