Explain Codominance Using the Abo Blood Groups as an Example

Chorionic villus sampling (CVS) may be performed early in pregnancy to find certain problems with the fetus. Determine and describe the extraembryonic membrane that is being sampled.

Anencephaly, a fatal condition, results from the failure of the anterior end of the neural tube to close properly, causing failure of the forebrain to develop. Determine and discuss the germ layer involved in this defect.