PSY440H5 Chapter Notes -Central Nervous System, Sympathetic Nervous System, Somatic Nervous System
As such, any biological or environmental influence can become part of this system and cannot be considered in an isolated context. The nature of genes: genes are segments of deoxyribonucleic acid (dna) that contain information about specific characteristics. Each human cell contains 46 chromosomes (arranged in 23 pairs half from each parent). Recessive gene must be paired with another recessive gene to determine a trait: defective gene results if something is wrong with respect to the ordering of dna molecules on the double helix. Genes seldom determine our physical development in any absolute way and the same is true for psychopathology. Much of human development and behavior is polygenic (i. e. , influences by many genes that individually exert a tiny effect). Because of this, scientists look for patterns of influence across genes using a procedure called quantitative genetics. New developments in the study of genes and behavior. An example of gene-environment interaction was proposed by eric.