LESSON 2: FACTORS IN THE DEVELOPMENT OF THE PHYSICAL SELF
 The development of the individual is caused by two interacting forces:
 HEREDITY
 ENVIRONMENT
HEREDITY (NATURE)
 The transmission of traits or characteristics from parents to offspring.
 It provides the raw materials of which the individual is made up.
ENVIRONMENT (NURTURE)
 The sum total of the forces or experiences that a person undergoes from conception to old age.
 It includes family, friends, school, nutrition, and other agencies one is in contact with.
THE BEGINNING OF LIFE
 LIFE BEGINS AT FERTILIZATION
 FERTILIZATION
 Refers to the meeting of the female sex cell and the male sex cell.
 These sex cells are developed in the reproductive organs called gonads.
 Gonads
 Testes – male gonads
 Ovaries – female gonads
 Sex cells
 Spermatozoa – refers to the male sex cell
 Ova – refers to the female sex cell
 The fertilized egg cell known as zygote contains all the hereditary potentials from the parents.
 Continues to grow during the gestation period of about 280 days or 36 weeks or 9 calendar
months.
 Chromosomes
 A thread like structure of nucleic acids and protein found in the nucleus of most living cells,
carrying genetic information in the form of genes.
 Chromosomes
 A male parent may pass either and X or Y chromosome.
 A female always gives the X chromosome.
 chromosomeS
XX or Female Offspring
 When an X chromosome comes from the father and meets the X chromosome from the mother
XY or Male Offspring
 When the father produces a Y chromosome which pairs with the X chromosome from the
mother
 genes
 Both male and female chromosomes contain several thousand of genes.
 Within the gene is a substances called deoxyribonucleic acid (DNA) which is the code of
heredity.
 Contains information and instructions about the newly created organism, and programs the
traits that should be inherited.
STAGES IN THE LIFE SPAN

STAGES OF HUMAN DEVELOPMENT
 Taking care of my physical self
 Self is inseparable from the body, you should take very good care of your physical self.
 Whether you plan to lose, gain or maintain weight, the most important thing to do is to keep
yourself fit. To achieve this goal, a rigid plan has to be made.
 Balanced diet
 Eating a balanced diet means consuming the right kind of food at the right time and in the right
proportion.
 Water
 An individual should drink at least eight glasses of water every day.
 It allows the body to function efficiently.
 Also washes away wastes to keep the skin clear and healthy.
 sleep
 Sleep gives the bones, muscles, and the mind time to recover.
 We need eight(8) or more hours of sleep a day.
 If one sleeps in a slumped, uncomfortable position in a mattress that is too soft, body aches may
develop.