-
Period: to
Zygote
-
Period: to
Embryo
-
Heart beats regularly eyes and ears begin to form.
4 week old embryo. -
Heart develops left and right chambers.
8 week old embryo. -
Period: to
Fetus
-
Bones are visible and a heartbeat can be heard.
4 to 6 month old fetus. -
Fingerprints form.
6 month old fetus. -
Eyelids open and can weigh up to 6.6 pounds
6 to 9 month old fetus. -
Period: to
Infancy
-
Baby can hold is head up and reach for objects.
3 months old. -
Infant begins to crawl.
7 months old. -
Period: to
Childhood
-
Ovulation in females and sperm production in males begin.
Ages 9 to 15. -
Period: to
Puberty
-
Period: to
Adolescence
-
Period: to
Adulthood
-
Skin becomes wrinkled
Age 30 skin will become wrinkled. -
Aging begins
30 years old. -
Aging is more noticable and progresses faster.
Ages 45 to 60.
