Exam 52: Animal Development

Referring to the figure of sperm penetration and fusion,match the lettered description with the correct numbered step in the figure. A. Some of the zona pellucida is degraded by acrosomal enzymes. B. Enzymes are released by cortical granules that harden the zona pellucida. C. Sperm and egg fuse at the plasma membrane. D. Sperm penetrates the corona radiata. E. The sperm nucleus dissociates and enters the cytoplasm. F. Additional sperm can no longer penetrate. -Step V

The developing embryo of reptiles,birds,and mammals is encased in the fluid-filled ________ membrane.

In a normal mammalian birth,how does the body guarantee that birth proceeds to completion?

What pattern of cleavage is characteristic of mammals?

In mammals,embryonic cells form an inner cell mass that will become the body of the embryo and a layer of surrounding cells that will become the chorionic membrane and placenta.What are these surrounding cells called?

Removing some fluid from directly around a developing human fetus is performed by inserting a long needle into the belly of the female patient.What extraembryonic membrane will be punctured in this process?

What actually begins the uterine contractions which leads to giving birth?

What human organ is formed from two genetically-different tissues?

Which of the following result from sperm penetration? (Check all that apply.)

A research group claims that they have discovered microscopic fossilized embryos,including some at the blastula stage,but other researchers are skeptical.Finally,one student develops a technique for splitting the embryos in half to reveal the substructure.Cutting open the first blastocyst embryo,the student is very excited."It is a blastula!" she shouts,"Look,you can see the ________ inside!"

The human placenta is formed by the interaction of uterine tissue and what extraembryonic tissue?

Which of the following leads to the occurrence of vertebrate sense organs?

Referring to the figure of sperm penetration and fusion,match the lettered description with the correct numbered step in the figure. A. Some of the zona pellucida is degraded by acrosomal enzymes. B. Enzymes are released by cortical granules that harden the zona pellucida. C. Sperm and egg fuse at the plasma membrane. D. Sperm penetrates the corona radiata. E. The sperm nucleus dissociates and enters the cytoplasm. F. Additional sperm can no longer penetrate. -Step VI

In the famous Spemann-Mangold experiment,what detail was crucial to understanding the result?

What factors stimulate uterine contractions and birth?

What factor has the strongest influence on the cleavage pattern of an embryo?

What is critical to the development of neural crest cell derivatives?

Referring to the figure of sperm penetration and fusion,match the lettered description with the correct numbered step in the figure. A. Some of the zona pellucida is degraded by acrosomal enzymes. B. Enzymes are released by cortical granules that harden the zona pellucida. C. Sperm and egg fuse at the plasma membrane. D. Sperm penetrates the corona radiata. E. The sperm nucleus dissociates and enters the cytoplasm. F. Additional sperm can no longer penetrate. -Step III

Choose the letter of the best match from the following: -The heart begins to beat.

What is the period of rapid cell division in which the embryo does not increase in overall size?