Blastocyst
A common feature of a vertebrate blastula is that it consists of a layer of blastomeres, known as the blastoderm, which surrounds the blastocoele. In mammals the blastula is referred to as a blastocyst. The blastocyst contains an embryoblast (or inner cell mass) that will eventually give rise to the definitive structures of the fetus, and the trophoblast, which goes on to form the extra-embryonic tissues. A blastula is a sphere of cells surrounding a blastocoele. The blastocoele is a fluid filled cavity which contains amino acids, proteins, growth factors, sugars, ions and other components which are necessary for cellular differentiation. The blastocoele also allows blastomeres to move during the process of gastrulation. 1 Although the embryo’s form emerges gradually as it develops, aspects of the developmental plan are already in place in the eggs of many species. 2  An organism’s development is primarily determined by the genome of the zygote and also by differences that arise between early embryonic cells. 1 The sperm and egg plasma membranes fuse, and the sperm nucleus enters the egg’s cytoplasm. 2  Na+ channels in the egg’s plasma membrane open. 3  Na+ flows into the egg, and the membrane depolarizes, changing the membrane potential of the egg. 4  Such depolarization is common in animals. the inner cell mass of the blastocyst develops into the blastodisk (similar to that in chickens). Early stages of development of the mammalian embryo, such as primitive streak stage, neurulation and germ layer differentiation, are similar to that occurring in chickens and reptiles. - the head, which contains the genetic material and is capped by the acrosome (cap) at the apex that contains enzymes needed for the sperm to penetrate the egg. - the middle piece contains the primary power source of mitochondria that fuel the movements of the tail piece. From egg to organism, an animal’s form develops gradually. 1  The question of how a zygote becomes an animal has been asked for centuries. 2  As recently as the 18th century, the prevailing idea was preformation, the notion that an egg or sperm contains an embryo that is a preformed miniature adult. 1 The sperm and egg plasma membranes fuse, and the sperm nucleus enters the egg’s cytoplasm. 2  Na+ channels in the egg’s plasma membrane open. 3  Na+ flows into the egg, and the membrane depolarizes, changing the membrane potential of the egg. 4  Such depolarization is common in animals. Gastrulation in Amphioxus. begins by the flattening of the blastula, loss of the blastocoel, and formation of the archenteron-the embryonic gut cavity that is lined with endoderm. After flattening, two cell layers can be distinguished-ectoderm and endoderm. - the head, which contains the genetic material and is capped by the acrosome (cap) at the apex that contains enzymes needed for the sperm to penetrate the egg. - the middle piece contains the primary power source of mitochondria that fuel the movements of the tail piece. The blastula (from Greek βλαστός (blastos), meaning sprout) is a hollow sphere of cells, referred to as blastomeres, surrounding an inner fluid-filled cavity called the blastocoele formed during an early stage of embryonic development in animals. A blastula is a sphere of cells surrounding a blastocoele. The blastocoele is a fluid filled cavity which contains amino acids, proteins, growth factors, sugars, ions and other components which are necessary for cellular differentiation. The blastocoele also allows blastomeres to move during the process of gastrulation. The cells migrate inward at the blastopore, which forms, or is close to, the location of the anus in the adult. the ectoderm forms the outer tube of the embryo. the endoderm is an inner tube that forms the alimentary canal and all its derivative organs. the mesoderm lies between these two layers. - the head, which contains the genetic material and is capped by the acrosome (cap) at the apex that contains enzymes needed for the sperm to penetrate the egg. - the middle piece contains the primary power source of mitochondria that fuel the movements of the tail piece. The fact is that all of those structures in all organisms are derived from a single cell that was formed by the union of two gametes. Every organism you see came originally from a single cell, which divided and differentiated to form more complex structures. - the head, which contains the genetic material and is capped by the acrosome (cap) at the apex that contains enzymes needed for the sperm to penetrate the egg. - the middle piece contains the primary power source of mitochondria that fuel the movements of the tail piece.
https://en.wikipedia.org/wiki/Blastula http://www.course-notes.org/Biology/Outlines/Chapter_47_Animal_Development http://www.shsu.edu/~bio_mlt/Chap5.html http://www.course-notes.org/Biology/Outlines/Chapter_47_Animal_Development http://www.shsu.edu/~bio_mlt/Chap5.html https://en.wikipedia.org/wiki/Blastula http://www.shsu.edu/~bio_mlt/Chap5.html http://www.shsu.edu/~bio_mlt/Chap5.html
what is the mammalian version of a blastula