Skip to Content


Pronunciation: o'o-tid

Definition: The nearly mature oocyte after the first meiotic division has been completed and the second initiated; in most higher mammals, including humans, the second meiotic division is not completed unless fertilization occurs. Thereafter the ootid contains two separate haploid elements, the female and male pronuclei. When the pronuclei fuse, the ootid becomes a zygote.

[G. ootidion, a diminutive egg. See -id (2)]

Disclaimer: This site is designed to offer information for general educational purposes only. The health information furnished on this site and the interactive responses are not intended to be professional advice and are not intended to replace personal consultation with a qualified physician, pharmacist, or other healthcare professional. You must always seek the advice of a professional for questions related to a disease, disease symptoms, and appropriate therapeutic treatments.
© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.