Perhaps the greatest mystery of all is the human body. Its nearly 100 trillion cells coordinate their efforts to allow us to move, eat, think and feel. In this section of Life Begins we uncover the mysteries of the genetic code and learn more about the process of maturation. A highlight is a section covering health issues and concerns.

Acne
Addictive substances
Adolescence
Anorexia nervosa
Atoms
Bulimia nervosa
Calories
Cell differentiation
Cells
Cholesterol
Chromosomes
Circulatory system
Dental check-ups
Deoxyribonucleic acid (DNA)
Depression
Diets
Digestive system
DNA in sex cells
Endocrine system
Exercise
Fad diets
Food pyramid
Genes
Growth spurt
Health Issues
Heart disease
Hormones
Hygiene

Integumentary system
Lymphatic system
Maturation
Medical check-ups
Meiosis
Mental health
Mitosis
Molecules
Muscular system
Nervous system
Nutrition
Organelle
Organism
Physical health
Pituitary gland
Puberty
Respiratory system
Sex cells
Sex chromosomes
Sex determination
Sex roles
Sexual development
Skeletal system
Stress
Suicide
Tissues
Vitamins
Weight gain