AP Psych Module 3.2a Physical Development Across the Lifespan: Prenatal Development, Infancy, and Childhood

Germinal Stage

the first two weeks of prenatal development, during which the fertilized egg (zygote) undergoes rapid cell division and implants into the uterine wall

Zygote

the fertilized egg

Embryonic Stage (Embryo)

the developing human organism from about 2 weeks after fertilization through the second month

Fetal Stage (Fetus)

the developing human organism from 9 weeks after conception

Placenta

the life-link that transfers nutrients and oxygen from mother to embryo

Teratogens

agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm

Fetal Alcohol Syndrome (FAS)

physical and cognitive function deficits in children caused by their birth mother’s heavy drinking during pregnancy. In severe cases, symptoms include a small, out-of-proportion head and distinct facial features

Habituation

decreasing responsiveness with repeated stimulation. As infants gain familiarity with repeated exposure to a stimulus, their interest wanes and they look away sooner

Maturation

biological growth processes that enable orderly changes in behavior, relatively uninfluenced by experience

Critical Period

an optimal period early in the life of an organism when exposure to certain stimuli or experiences produces normal development

Epigenetics

the study of how environmental factors (e.g., alcohol exposure) can affect gene expression without changing the DNA sequence

Reflexes

automatic responses newborns are born with (e.g., sucking, grasping, rooting reflex)