Exam 38: Animal Development

Experiments on amphibian embryos have shown that the notochord secretes Chordin and Noggin.If you performed an experiment in which you blocked the production of Chordin and Noggin in the early embryo,the expected result would be an embryo

In humans,the amnion forms from the

Genetic testing of an embryo is available to couples who want to avoid passing on a genetic defect to their offspring.One method of testing involves removing a single blastomere from an 8-cell stage embryo and analyzing it to determine if it carries the mutant gene.If no mutation is found,the now 7-cell embryo can be implanted in the woman,and it can go on to develop into a healthy infant.These results indicate that

The mesoderm

Which statement about the neural tube is true?

Hans Spemann and Hilde Mangold's famous experiment involved transplanting mesodermal tissue from the _______ of an early gastrula stage salamander embryo.

What is the difference between a human fetus and embryo?

You are presented with an egg that is so rich in yolk that cleavage furrows do not pass entirely through the yolk.As development proceeds,a disc of cells accumulates on top of the yolk to form the embryo.This egg is most likely not the egg of a(n)

Which statement about the umbilical cord is true?

Following gastrulation in vertebrates,the mesodermal cells contribute to the developing

In amphibian eggs,cells migrate to the interior of the embryo through the blastopore.In mammalian embryos,this migration occurs at the

The region of the frog egg that is darkly pigmented is known as the _______ pole.

Following gastrulation in vertebrates,the endodermal cells contribute predominantly to the developing

If the blastopore dorsal lip is grafted from one salamander embryo onto a second embryo,the second dorsal lip will

The cells that form the neural tube come from the

The process in development by which germ layers form and take specific positions relative to one another is called _______.

The developing human is most susceptible to the occurrence of birth defects from radiation or chemical insults

The figure shows that,relative to the rest of the body,the _______ in a newborn baby is/are larger than in an adult.

Exposure to toxins is particularly dangerous to the embryo in the first trimester of pregnancy because

If a cell is removed from an eight-cell embryo and a particular portion of the organism fails to form,the development is termed