The yellow spheroidal mass of stored food that forms the inner portion of the egg of a bird or reptile and is surrounded by the white. [ http://purl.obolibrary.org/obo/BTO_0000371 http://en.wikipedia.org/wiki/Yolk ]

This is just here as a test because I lose it

Term information

database cross reference
definition
  • The yellow spheroidal mass of stored food that forms the inner portion of the egg of a bird or reptile and is surrounded by the white.
external definition
  • Extraembryonic structure that serves as a nutrient store for the embryo during development.[AAO]
function notes
  • nutrient store
homology notes
  • The majority of animals develop from a spherical egg with a single axis, the animal-vegetal (an-veg) axis. The animal half of the egg usually contains the nucleus of the oocyte, while the vegetal half of the egg is the preferred site for the storage of yolk. Eggs with an-veg polarity are considered ancestral for the vertebrates. Frogs, for example, have eggs with vegetally concentrated yolk and the nucleus located in the animal cytoplasm.[well established][VHOG]
id
  • UBERON:0007378

Term relations