2. embryo
3. fetus
4. teratogens
5. fetal alcohol syndrome
6. habituation
7. maturation
8. cognition
9. schema
10. assimilation
11. accommodation
12. sensorimotor stage
13. object permanence
14. preoperational stage
15. conservation
16. egocentrism
17. concrete operational stage
18. formal operational stage
19. stranger anxiety
20. attachment
21. critical period
22. imprinting
23. theory of mind
24. autism
25. self-concept
26. X chromosome
27. Y chromosome