Heredity and Environment

• HEREDITY AND ENVIRONMENT

  -          two factors of development;    nature and nurture

  -          inherited traits and individual’s experiences
• Heredity


  -          process whereby traits of parents are handed down to their offspring via the genes
• Environment


  -          refers to all forces that affect man like physical forces, natural forces and the social forces
• SEX DETERMINATION


  -          the sex of the offspring depends on the pairing of the sex chromosomes from the mother and father

  -          parents: xx = mother, x/y = father

  -          offspring: xx = girl, xy = boy
• MECHANICS OF HEREDITY

  -          46 chromosomes or 23 pairs of chromosomes

  -          chromosomes, thread like or rope like bodies that contain the genes

            -          usually in pairs, if not, this can result to chromosomal aberration and abnormalities of some kind

            -          classified as: autosomes/trait chromosomes, gonosomes/sex chromosomes
• GENES


  -          real bearers of hereditary traits 

            -          dominant genes, the strong genes and the trait dominant genes carry will always be manifested in the offspring

            -          recessive genes, the weak genes and the trait that a recessive gene carries can only be manifested if it is paired with another recessive gene of its kind