Search results
Results From The WOW.Com Content Network
Gosner stage is a generalized system of describing stages of embryonal and larval development in anurans (frogs and toads). The Gosner system includes 46 numbered stages, from fertilized embryo (stage 1) to the completion of metamorphosis (stage 46). It was introduced by Kenneth Gosner in 1960. [2]
In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm cell, ( spermatozoon ). [ 1] Once fertilized, the ovum becomes a single diploid cell known as a zygote.
The embryonic development of tailless amphibians is presented below using the African clawed frog (Xenopus laevis) and the northern leopard frog (Rana pipiens) as examples. The oocyte in these frog species is a polarized cell — it has specified axes and poles.
A neurula is a vertebrate embryo at the early stage of development in which neurulation occurs. The neurula stage is preceded by the gastrula stage; consequentially, neurulation is preceded by gastrulation. [1] Neurulation marks the beginning of the process of organogenesis. [2] Mice, chicks, and frogs are common experimental models for ...
e. Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation of stem cells in the adult organism.
Anatomical terminology. [ edit on Wikidata] Gastrulation is the stage in the early embryonic development of most animals, during which the blastula (a single-layered hollow sphere of cells ), or in mammals the blastocyst, is reorganized into a two-layered or three-layered embryo known as the gastrula. [ 1]
An amphibian embryo in the 128- cell stage is considered a blastula as the blastocoel in the embryo becomes apparent during this stage. The fluid-filled cavity forms in the animal hemisphere of the frog. However, the early formation of the blastocoel has been traced back to the very first cleavage furrow.
Blastulation. Blastulation is the stage in early animal embryonic development that produces the blastula. In mammalian development, the blastula develops into the blastocyst with a differentiated inner cell mass and an outer trophectoderm. The blastula (from Greek βλαστός ( blastos meaning sprout )) is a hollow sphere of cells known as ...