An embryo (/ ˈɛmbrioʊ / EM-bree-oh) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life …

In organisms that reproduce sexually, the union of an ovum with a sperm results in a zygote, or fertilized egg, which undergoes a series of divisions called cleavages as it passes down the …

: an animal in the early stages of development that are marked by cleavage, the laying down of the basic tissues, and the formation of primitive organs and organ systems compare fetus. : a …

Oct 14, 2025 · Timing is what sets apart an embryo from a fetus. Learn more about the stages of your baby’s development here.

4 days ago · Scientists have developed an experimental way to study how human embryos implant in a uterus, which may provide new insights into why miscarriages occur and how they …

Not only do embryos get bigger during that time, but they also go from being just a simple, single, cell to being the many cells that make up a human. All of a human’s features, organs, and …

Jul 22, 2025 · Human embryo development begins with fertilization, the union of a sperm and an egg, typically in the fallopian tube. This fusion forms a single-celled zygote, containing a …

Use the stage number links to images and information about each specific stage of human development over the first 8 weeks. The links below give a broad overview of developmental …

Aug 13, 2023 · In Biology, an embryo is designated as the initial phase of development for a multicellular organism arising after the fusion of a sperm cell (male sex gamete) and an egg …

EMBRYO definition: 1. an animal that is developing either in its mother's womb or in an egg, or a plant that is…. Learn more.