Embryo Development

Begins with contact between egg and sperm, ends with transfer of paternal chromosomes into the egg to form a zygote

the process ofd vision, single-cell zygote begins a series of organized, successive mitosis to produce a multicellular, hollow structured called the blastula; no growth of embryo

the period of cell movement; starts with the formation of a curved groove (blastopore) in the region formally occupied by the gray crescent

stage 1; appears as a large cell with a clear nucleus and nucleolus

stage 2; a region located opposite the site of sperm penetration, becomes the dorsal side, where gastrulation will begin

stage 3; The result of the first cleavage event after fertilization

stage 4; The result of a second cleavage event

stage 6

stage 8; characterized by continued irregular cleavage and intrusion of pigmented area over pale area

stage 9; cells in animal hemisphere are small and pigmented and extend and well down toward the vegetal pole

stage 10; The region above the blastopore on the dorsal side of the amphibian embryo.

stage 11; the groove of the blastopore and the dorsal lip have spread to form a circle around the small area of the remaining yolk

stage 12; Blastoporeformed, surrounding yolk plug, blastopore elevated to point of posterior axis of embryo.

fertilized egg

made of proteins and lipids

yolky side

dark colored

a multicellular, hollow structure produced after a series of organized successive mitoses

each cell of the blastula

the central cavity of the blastula

the opening though which the cells on the surface of the embryo begin migrating to the Indies (into the blastocoel)

The region above the blastopore on the dorsal side of the amphibian embryo

the remaining yolk in which the dorsal lips forms a circle around

outer germ layer, the brain and spinal cord

middle germ layer, muscles, skeleton, urogenital organs, muscle layer, and outer walls of digestive and respiratory tracts

outer germ layer; inner lining of digestive and respiratory tracts

the cavity formed by the endoderm; primitive gut; replaces the blastocoel and will eventually form the lumen of the digestive tract

blastopore will form anus opening first

processes by which the cells of the three primary germ layers form actual organ systems in the embryo

cells express their different morphological and functional specializations

the flattening of the neural ectoderm

forms when the neural plate rolls up at the edges

area between the neural folds

formed when the neural folds eventually fuse together to form an enclosed, hollow structure, ultimately forms the brain and spinal cord

A flexible rod that supports a chordate's back

A group of large, nutrient-laden endodermal cells surrounded by the completed blastopore in an amphibian gastrula. These cells will be covered by ectoderm and end up inside the embryo.

tail fin circulation

mouth open, cornea transparent

gill circulation

heart beat

muscular response

tail bud

neural tube

rotation

neural folds

neural plate, dorsal flattening