embryo development ending in birth or egg hatching

Definition

Target type: biologicalprocess

The process whose specific outcome is the progression of an embryo over time, from zygote formation until the end of the embryonic life stage. The end of the embryonic life stage is organism-specific and may be somewhat arbitrary; for mammals it is usually considered to be birth, for insects the hatching of the first instar larva from the eggshell. [GOC:go_curators, GOC:isa_complete, GOC:mtg_sensu]

Embryo development is a complex and fascinating process that begins with the fertilization of an egg by a sperm, resulting in the formation of a zygote. This single-celled zygote undergoes a series of rapid cell divisions, known as cleavage, to form a multicellular structure called a blastula.

The blastula then undergoes gastrulation, a process where the cells rearrange themselves to form the three primary germ layers: the ectoderm, mesoderm, and endoderm. These layers will eventually give rise to all of the tissues and organs of the developing embryo.

As the embryo grows, it differentiates and develops specialized organs and systems. The ectoderm develops into the nervous system, skin, and sensory organs. The mesoderm forms the muscles, skeleton, circulatory system, and reproductive organs. The endoderm gives rise to the digestive system, lungs, and other internal organs.

During this process, the embryo is typically protected within a specialized structure, such as an amniotic sac in mammals or a shell in birds and reptiles. This provides a stable environment for development, with nutrients and waste products being exchanged through the placenta in mammals or through the eggshell in other species.

As the embryo develops further, it undergoes organogenesis, where the various organs begin to take shape and function. This is a complex and tightly regulated process that ensures the proper development of all organ systems.

Finally, after a period of gestation, the embryo is ready for birth or hatching. In mammals, the embryo is born as a live offspring, while in birds, reptiles, and amphibians, it hatches from an egg. After birth or hatching, the offspring continues to grow and mature, gradually becoming an independent adult.

This detailed process involves a multitude of intricate cellular and molecular events, each contributing to the overall developmental program. It is a testament to the power of evolution and the remarkable ability of living organisms to generate complex and functional structures from a single fertilized egg.'
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Proteins (4)

Compounds (187)