1. Most birth defects can be traced to disruption of the developmental events during this part of the prenatal period: (a) first 2 weeks, (b) second half of month 1 and all of month 2, (c) month 3,...

1. Most birth defects can be traced to disruption of the developmental events during this part of the prenatal period: (a) first 2 weeks, (b) second half of month 1 and all of month 2, (c) month 3, (d) end of month 4, (e) months 8 and 9.

2. The primary germ layer that forms the trunk muscles, heart, and skeleton is (a) ectoderm, (b) endoderm, (c) mesoderm.