Certificate In Psychology (CPSY) Practice Exam 2025 – All-in-One Resource for Exam Success!

The correct answer is the fetal period. This stage of prenatal development occurs from approximately the 9th week of gestation until birth and is characterized by significant growth and development of the fetus. During this time, the organism increases in weight dramatically, starting from a very small size and reaching about 7 pounds or more by the time of delivery.

In the fetal stage, the internal organs and systems become more complex and functional, and there is considerable development of body structures, leading to substantial increases in size and weight.

The embryonic period, which is the stage preceding the fetal period, involves critical development processes such as organ formation but does not typically see the same level of weight gain. The germinal stage is even earlier, marked by the first two weeks after conception when the zygote is forming and implanting into the uterine wall, with minimal increase in weight. The conceptual stage, while not a standard term used in prenatal development, would refer to the very early stages of fertilization and does not involve significant growth either.

Hence, the fetal period is defined by the rapid physical growth that occurs in preparation for birth, which explains why it is associated with the increase in weight from approximately 0.02 pounds to about 7