A Reproductive Lexicon


Ownership of this website has been transferred from Northwestern University to Michigan State University.
Please note that some site information may be inaccurate while adjustments to reflect this organizational change are made.

MOOC Advertisement

Learn More:
Get An Introduction to Reproduction

Learn more about the science of reproduction. Dr. Teresa Woodruff, creator of Repropedia, is offering a free online course exploring the world of reproduction.

Get Started!

vitelline membrane

The vitelline membrane is a structure that directly surrounds the oocyte in lower organisms, such as insects, mollusks, amphibians, and birds. Its functional homologue in mammals is the zona pellucida.