Exam 43: Animal Development

__________diffuse(s) from fetal blood to maternal blood in the placenta.

The umbilical cord of a mammal connects the

In what ways are the juveniles of direct-development species like their parents, and in what way are they different?

A human embryo has webbed fingers. Why are human babies not usually born with webbed fingers?

In blastulas, if cells from an area that would normally become skin are transplanted into an area that would become the nervous system, the transplanted cells will form structures of the nervous system.

The developmental fate of each cell is determined by chemical interactions among cells in a process called __________.

Most microbes cannot gain access to the fetus. However,__________ , which causes syphilis in adults, can cross the placenta and attack the fetus, causing stillbirths and mental retardation.

In a reptile egg, which membrane is analogous to a lung?

A morula is a solid ball of undifferentiated cells.

In a bird egg, the__________ provides the watery environment in which the embryo develops.

The cells of an aging animal function less efficiently because

The metamorphosis of a caterpillar into a butterfly is an example of

The nervous system develops from the endoderm.

The placental blood vessels

In the 1920s, two German embryologists, Hans Spemann and Hilde Mangold, demonstrated that a small patch of cells, called the dorsal lip of the blastopore, would

In humans, fertilization occurs in the

Which of the following is the result of gastrulation?

The outer cell layer of the blastocyst becomes the __________, which forms the embryonic portion of the placenta.

-Metabolic wastes may be stored within structure 4, the

At 10 weeks, the blastocyst becomes an embryo.