| A | B |
| fertilization | the union of a male sperm cell and a female egg cell |
| implantation | a process in which the zygote attaches to the uterine wall |
| embryo | te cluster of cells taht develop between the third and eighth weeks of pregnancy |
| fetus | de developing group of cells after about the eighth week of pregnancy |
| amniotic sac | a thin, fluid-filled membrane that surrounds and protects the developing embryo |
| umbilical cord | a ropelike structure that connects the embryo and the mother;s placenta |
| placenta | a thick, blood-rich tissue that lines the walls of the uterus during pregnancy and nourishes the embryo |
| labor | the final stage of pregnancy in which the uterus contracts and pushes the baby out of the mother's body |
| prenatal care | steps that a pregnant female can take to provide for her own health and the health of her baby |
| birthing center | a facility in which women with low-risk pregnancies can deliver their babies in a homelike setting |
| fetal alcohol syndrome (FAS) | a group of alcohol-related birth defects that includes both physical and mental problems |
| miscarriage | the spontaneous expulsion of a fetus that occurs before the twentieth week of a pregnancy |
| stillbirth | a dead fetus expelled from the body after the twentieth week |
| heredity | the passing of traits from parents to their children |
| chromosomes | threadlike structures found within the nucleus of a cell that carry codes for inherited traits |
| genes | the basic units of heredity |
| DNA | the chemical unit tat makes up chromosomes |
| genetic disorder | disorders caused partly or completely by a defect in genes |
| amniocentesis | a procedure in whih a syringe is inserted through a pregnant female's abdominal wall into the amniotic fluid surrounding the developing fetus |
| chorionic villi sampling | a procedure in which a small piece of membrane is removed from teh chorion, a layer of tissue that develops into the placenta |
| gene therapy | the process of inserting normal genes into human cells to correct genetic disorders |
| developmental tasks | events that need to happen in order for a person to continue growing toward becoming a healthy, mature adult |
| autonomy | the confidence that a person can control his or her own body, impulses, and environment |
| scoliosis | an abnormal lateral, or side-to-side, cirvature of the spine |