Animal Development Ch 47 Section 1

As gastrulation is completed, the circular lip of the blastopore encircles a ___________ consisting of the outer nutrient-laden cells; these protruding cells will move inward as expansion of the ectoderm causes the blastopore to shrink further.

Running along the embryo's anterior-posterior axis, the pileup of cells moving inward at the blastoderm's midline produces a thickening called 

During this process, various regions of the three embryonic germ layers develop into the rudiments of organs.

This is the outer epithelium of the blastocyst. It does not contribute to the embryo itself but instead provides support services.

The allantois in mammals is incorporated into the __________.

During this stage of fertilization interactions and movements of the three layers generate rudimentary organs from which adult structures grow.

When the head of a sea urchin sperm contacts the jelly coat of a sea urchin egg, molecules in the egg's coat trigger the __________ ___________ in the sperm.

The yolk concentration decreases significantly toward the opposite pole called the________. This is also the site where the polar bodies of oogenesis bud from the cell.

Hollow ball of cells during cleavage.

Fluid filled cavity in the process of cleavage.

Yolk is often concentrated toward one pole of the egg called the 

The incomplete division of a yolk-rich egg is known as

The process by which an organism takes shape and the differentiation cells occupy their appropriate locations.

The second stage of fertilization

This stage of fertilization rearranges the blastula into a three-layered embryo, the gastrula.

The process in which the remaining cells near the vegetal pole flatten slightly and form a vegetal plate that buckles inward as a result of cell shape changes.

The part above the crease during gastrulation of a frog becomes the dorsal side of the blastopore, called the

The skeletal rod characteristic of all chordate embryos. One of the first organs to begin to take shape.

The ____________ in mammals is incorporated into the umbilical cord.

The third stage of fertilization

Extracellular matrix of an egg

First, it initiates implantation by secreting enzymes that break down molecules of the endometrium, the lining of the uterus.

Specialized vesicle at the tip of the sperm of a sea urchin.

This will become the animal's central nervous system

The rim of the cytoplasm

Cellular respiration and protein synthesis by the egg

As the blastoderm is forming, future endoderm and mesoderm cell layers on the surface of the embryo roll over the edge of the lip into the interior of the embryo, a process called 

The mammalian version of a blastula during the embryonic stage

Then, as it thickens through cell division, it extends fingerlike projections into the surrounding maternal tissue, which is rich in blood vessels.

The open end of the archenteron, which will become the anus, is called the 

The ectoderm above the notochord becomes the __________ in response to a number of signaling molecules secreted by mesodermal and other tissues.

Vesicles lying just beneath the egg plasma membrane, in the rim of the cytoplasm, that are key players in the longer-lasting polyspermy block.

Within seconds after sperm binds to the egg, cortical granules fuse with the egg plasma membrane, initiating the________ _________.

The pattern in animals, whose eggs contain relatively little yolk, in which the blastocoel is centrally located, ant the cleavage furrow passes all the way through the cells.

The three layers produced by gastrulation are embryonic tissues collectively called the embryonic __________.

Disposes of waste products and contributes to gas exchange.

• Chorion

• Amnion

• Yolk sac

• Allantois

This reaction begins when a specialized vesicle at the tip of the sperm discharges hydrolytic enzymes.

Morphogenic process taking up new locations that will allow the later formation of tissues and organs.

One layer of the blastoderm(lies atop the yolk mass)

Along with cell division and differentiation, development involves _______.

First stage of fertilization

Molecules placed in the egg by the mother that include proteins and RNA's.

Below the developing embryo proper this encloses the yolk and provides nutrients until the time of hatching. 

• Chorion

• Amnion

• Yolk sac

• Allantois

A sperm must travel through this layer of follicle cells before it reaches the __________.

The buckled vegetal plate then undergoes extensive rearrangement of its cells, transforming the shallow invagination into a deeper, narrower, blind-ended tube called the

As a zygote divides, differences arise between early embryonic cells due to the _______ distribution of cytoplasmic determinants.

In this stage of fertilization cell division creates a hollow ball of cells, the blastula, from the zygote.

Eventually encloses the embryo in a protective, fluid-filled amniotic cavity.

• Chorion

• Amnion

• Yolk sac

• Allantois