Exam 8: Principles of Development

Somites,which form segmental muscles and vertebrae,develop from which germ layer?

Neighboring cells influence the development of each other,either by direct contact or by production of chemical signals,in

The major group of the animal kingdom that includes animals that in their development show spiral cleavage and mosaic development is the __________.

Mosaic development in animals

The product of cleavage in a zygote produces a cluster of small cells called

The conclusion of Spemann's work,in which he tied off a zygote isolating the nucleus on one side and only cytoplasm on the other,helped prove

The special blastomere labeled the 4-d cell often gives rise to the

In nearly all metazoa,"germ layers" is a term that describes

Rotational cleavage is unique to

An enterocoelous animal has

A primitive streak appears during gastrulation of

The cortical reaction that follows fertilization causes a hardening of the vitelline envelope to produce the _________ _________.

Entrance of more than one sperm

Which of the following is NOT characteristic of regulative development in animals?

The sac that surrounds the fetus and usually ruptures just before childbirth is the

The response to sperm fusing with the egg membrane causes enzyme-rich granules to ultimately cause the separation of the vitelline envelope and the egg membrane; this is called

In the human,which part of the blastocyst will develop into the embryo proper (versus the supporting placenta)?

The concept that an egg contains the building material that must somehow be assembled is called

The internal pouch representing the developing gut in a gastrula is called a _______

In animals,indirect development