Certificate In Psychology (CPSY) Practice Exam

Which period of prenatal development begins at conception?

1. germinal

2. chromosomal

3. fetal

4. embryonic

The correct answer is: germinal

The germinal period is the correct answer because it refers to the earliest stage of prenatal development that begins at the moment of conception. During this phase, the fertilized egg, or zygote, undergoes a series of rapid cell divisions as it travels down the fallopian tube toward the uterus. This period lasts approximately two weeks, during which the zygote becomes a blastocyst and prepares for implantation into the uterine wall. The other periods mentioned do not begin at conception. The embryonic period follows the germinal stage and lasts from the end of the second week until the end of the eighth week, during which major organs and structures begin to develop. The fetal period begins after this, at around the ninth week of pregnancy, and involves the growth and maturation of the already developed structures. The term "chromosomal" does not refer to a specific stage of prenatal development; rather, it relates to the genetic makeup and does not have the same structural significance in the context of prenatal growth.