Exam 43: Animal Development

Refer to the graph. In the graph, curve _______ best represents the changes in the ratio of nuclear volume to cytoplasmic volume during early cleavage in most animals.At this time, the blastomeres _______ in size.

An obstetrician can listen to the heartbeat of a fetus to determine the health of the heart and whether there is a multiple pregnancy.In which trimester of the pregnancy will the obstetrician first be able to hear the baby's heartbeat? Explain your answer.

Which statement about developing placental mammals is true?

The gray crescent in a frog zygote

Refer to the figure showing a stage of gastrulation in the frog. Consider a piece of ectoderm that is destined to be neural tissue in its original location in the gastrula shown in the figure.If it is transplanted into a location destined to be epidermis in a gastrula of similar age, which of the following will result?

Which structure in birds and mammals is the equivalent of the dorsal lip of the amphibian blastopore?

Which statement about germ cells is true?

A man who suffers from a mitochondrial disease due to a mutation in his mitochondrial DNA is worried he will pass this defect on to his children.A genetic counselor tells the man that there is a negligible probability of his passing this disease on to his offspring, because mitochondria are inherited from the _______.

Which result did Hans Spemann and Hilde Mangold get when they transplanted the dorsal lip of the blastopore of an early amphibian gastrula to the belly region of another early gastrula?

In each somite there are several regions of cells that give rise to different structures.Experimental destruction of one somite would impair the development of

Which statement about Hox genes in mammals is true?

The region of the frog egg with dark pigmentation, where fertilization can take place, is known as the _______ hemisphere.

Although details of gastrulation differ among sea urchins, frogs, and chickens, there is a common result in all of these animals.What is it?

An embryo exhibits abnormal development in the most posterior part of its body.The responsible Hox gene is located

If a researcher inhibited formation of filopodia during sea urchin gastrulation, which of the following would be least likely to form?

Which feature is characteristic of development in organisms whose eggs have little to a moderate amount of yolk?

A researcher experimentally blocks the protein that inhibits GSK-3 in a frog zygote.Which would be the most immediate effect?

The centriole of the sperm becomes the _______ of the zygote.

Refer to the figure showing a 9-day chick embryo. Match the following terms with their label numbers in the figure: allantoic membrane, allantois, amnion, body of embryo, chorion, and yolk sac.

You are observing a video of development in Xenopus (African clawed frog).Immediately following the segment on gastrulation, the video shows neural crest cells migrating toward their destinations, and you realize that the segment showing _______ is missing.