Core Lab

OBJECTIVE: Having finished lessons on mitosis & meiosis, the student shall demonstrate their ability to work in a lab environment with a new organism by carefully and efficiently carrying out fertilization of the sea urchin, writing up a lab report, and answering the implication questions.

PURPOSE: This lab is designed to provide students with a laboratory experience with sea urchins in which they will fertilize gametes and observe early developmental stages. Sea urchins are often used as research organisms and these labs give students the opportunity to have an authentic hands-on experience that has open ended applications.

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. Today we will study the living cells of the sea urchin performing the early stages of development.


1) injection of sea urchin to induce spawning
2) collection of gametes
3) dilution of sperm
4) fertilization of the sea urchin

STRUCTURED PRACTICE: Ask and answer questions while introducing the model to insure active participation and check for understanding.

GUIDED PRACTICE: Students fertilize eggs under the microscope, using gametes collected by the teacher. Students draw and describe the stages of development observed.

CLOSURE: Given the sea urchins method of fertilization and development, what are the special reproductive adaptations that contribute to the survival of sea urchins as a species?

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