Lesson 2 Genetic and Physical Development

• heredity - biological pattern as a result of a process of transmission of genetic characteristics from parents to the offspring
• chromosomes - microscopic particles that carries the hereditary units that we receive from our parents
• DNA(deoxyribonucleic acid)- the actual carrier of hereditary information within the genes
• RNA(ribonucleic acid) - partially carries special "hereditary instructions" for the cellular development of the organism
• if both members of a gene pair are dominant, the individual will manifest the trait determined by the genes
• if one is dominant and the other recessive, the individual will show the trait determined by the dominant gene
• a recessive form of the trait will only be expressed if both parents are recessive
• phenotype - genetic inheritance as noted in his observable characteristics
• genotype - genetic characteristics, seen and unseen, dominant and recessive
• pair 23 determines the sex of an individual and carries genes for certain traits that are called "sex-linked"
• the first 22 pairs are called autosomes
• x-type sperm + egg cell = female child
• y-type sperm + egg cell = male child
• the father's X chromosome determines a child's sex
• sex-linked - certain characteristics carried only by a recessive X chromosomes
• cell division changes the fertilized egg or zygote into a group of cells called blastula then becomes a two-layered hollow cup called gastrula
• the gastrula forms into three cells - the ectoderm(outer layer), the mesoderm(middle layer), and the endoderm(inner layer)
• 9 weeks until its birth, it's called a fetus
• Postnatal - extends from birth to death
• five stages of postnatal - infancy, early childhood, later childhood, adolescence, and adulthood
• infancy - extends to about age two, and ends when a child establishes relative independence as a result of motor, social, and cognitive growth
• early childhood - from age two to age six, and ends when all basic skill seen is well established
• later childhood - extends until puberty(12-13 yrs old)
• Pre-pubertal growth spurt - period of rapid growth before puberty starts
• Adolescence - from the start of puberty to age 18, ends with the completion of growth and an adult body configuration
• Adulthood - end of adolescence until death
• Heredity - the direction and pattern given by the genes to growth and development
• Maturation - the completion of growth and development
• Physical Environment - all the things that affect us directly(food) and the things that stimulate our sense organs(sights and sounds)
• Social Environment - includes all who in any way influence us
• direct, daily contact - families, friends, schoolmates, acquaintances
• indirect contact - radio and television, books, our imagination, memory, and daydreams