Definition

A thin, membranous sac that forms in the embryos of mammals, birds, and reptiles. It plays a key role in developing the umbilical cord and placenta in mammals.

Example

The allantois plays a crucial role in the development of the embryo by facilitating nutrient and waste exchange.

Conversation

Did you know that the allantois plays a role in the development of the umbilical cord?

Really? I had no idea it was that important!

Yeah, it's fascinating how it helps in forming the placenta too.

Science is amazing! I love learning about these things.

Synonyms & Antonyms

Root Explanation

Allantois → It is formed from "allantois" (from Greek "allantoin", meaning sausage or sausage-like) and the suffix "-is" (a common suffix in biological terms). The word refers to a sac-like structure in embryos that resembles a sausage, involved in waste storage and gas exchange.

Memory Tip

Imagine a 'sausage-like' ('allantoin') structure in embryos that helps with waste and gas exchange — that's what allantois refers to.

Visually Confused Words