20. Development

The development of a zygote into a blastula is called __________.

Which stage of development is common in amphibians but not seen in mammals?

Which of the following describes the correct sequence of stages during embryogenesis?

A sea urchin sperm penetrates the jelly coat of an egg and adheres to receptor proteins on the egg's surface as a result of __________.

How does a zygote differ from an ovum?

After a sperm penetrates an egg, a fertilization envelope forms. This envelope __________.

The period of repeated cell divisions without significant cell growth results in formation of the blastula and is called __________.

During cleavage the single large zygote is converted into a __________.

How is the animal hemisphere of a frog blastula different from the vegetal hemisphere?

What is the most likely trigger of egg activation?

Which of the following is true of meroblastic cleavage?

As an animal develops, organs form and the body transforms into a shape typical of the species in a process called __________.

People with Kartagener's syndrome suffer from a variety of ailments, including the intriguing condition known as situs inversus, a reversal of the abdominal and thoracic organs. This condition occurs because of __________.

The digits of a developing vertebrate limb respond to molecules that establish an anterior-posterior axis. These molecules originate in __________.

In an experiment on eye development, a thin piece of aluminum foil was placed between the bulging wall of the brain and the overlying ectoderm where the eye normally forms. Wherever the foil was placed, the lens failed to develop because the foil __________.