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  1. Embryo - Wikipedia

    A newly developing human is typically referred to as an embryo until the ninth week after conception, when it is then referred to as a fetus. In other multicellular organisms, the word …

  2. Embryo | Description, Characteristics, & Development | Britannica

    An embryo is the early developmental stage of an animal while it is in the egg or within the uterus of the mother. In humans the term is applied to the unborn child until the end of the seventh …

  3. EMBRYO Definition & Meaning - Merriam-Webster

    : 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 …

  4. Embryo | definition of Embryo by Medical dictionary

    embryo An organism in its earliest stages of development, especially before it has reached a stage at which it can be distinguished from other species. The human embryo is so called up …

  5. Embryo & Fetal Development: Complete Week-by-Week Guide …

    Comprehensive guide to embryo and fetal development from Week 1 to 40. Learn about the Germinal, Embryonic, and Fetal stages, key milestones, and critical factors for a healthy …

  6. Embryo vs. Fetus: How to Tell Them Apart - Verywell Health

    Oct 14, 2025 · An embryo is the early stage of development and lasts from week five to week 10 of pregnancy. A fetus is the later stage of development and lasts from the end of week 10 until …

  7. Embryo - Definition and Examples - Biology Online Dictionary

    Aug 13, 2023 · An embryo is a newly fertilized egg (zygote) up till the eighth week of development as it transforms through the morula, blastula, gastrula, and organogenesis stages.

  8. What Is an Embryo? A Look at Early Biological Development

    Jul 21, 2025 · An embryo represents the initial stage of development in a multicellular organism. This period is characterized by rapid cell division and the establishment of the basic body plan.

  9. What is the difference between an embryo, a fetus, and a baby?

    Aug 26, 2021 · When egg and sperm meet, a zygote is formed and quickly begins dividing to become an embryo. As pregnancy progresses, the embryo becomes a fetus. The fetus …

  10. 28.2 Embryonic Development – Anatomy & Physiology 2e

    The embryo, which takes the shape of an oval-shaped disc, forms an indentation called the primitive streak along the dorsal surface of the epiblast. A node at the caudal or “tail” end of …