Young do not need to run risks attendant with foraging themselves. 3. modification of extra-embryonic membranes to form the placenta, providing nutrients and disposing of wastes through the ...

For some animals, the entire process of cellular multiplication, generation of specialized cells, and their organization into an ordered multicellular embryo takes place in the protective environment ...

Amniotic egg appears very early in reptilian evolution. Egg has several special extra-embryonic membranes, which allow it to develop on land independent of water. Just as significant as evolution of ...

The fetal membranes consist of the chorion ... A remnant of the yolk sac merges in the forming embryo into the primitive gut. The role of the yolk sac in early gestation is to supply the embryo ...

During the first 72 hours in particular, extracellular vesicles—nanoparticles enclosed in cell membranes—play a significant role in the embryonic development of zebrafish. This is the result ...

Pictured here is a group of cells moving toward its correct final position in the tail of a forming zebrafish embryo. Cell membranes are green and the cell nuclei red. Disclaimer: AAAS and EurekAlert!