Mod 6 - Biological

Biological Psychology Summary 1: Behavioural genetics The study of how genes affect behaviour Genetics – the biology of inheritance Chromosomes – long thin structures in every biological cell that contain genetic information. Most human cells contain 23 pairs (total of 46). Genes – the biological instructions inherited from both parents and located on the chromosomes, that provide the blueprint for physical development. Genes controll the synthesis of protein. Deoxyribonucleic acid (DNA) – the molecular structure of a gene that provides the genetic code. Strands of sugar, phosphate. Ribonucleic acid (RNA) Mitosis – cell division – cells are copies Meiosis – male sperm and ova – the chromosome pairs are not copied, they randomly split and rearrange. Fertilised cell – zygote – identical twins developed from one fertilized egg cell are called monozygotic Polygenic – a term describing characteristics that are determined by more than one gene Genotype – the full set of genes, inherited from both parents, contained in 23 pairs of chromosomes. Phenotype – how an individual looks and acts, which depends on how inherited characteristics interact with the environment. Alleles – collection of different genes. Late 1800s, work of Sir Francis Galton (cousin of Charles Darwin) – famous research that genius runs in families. 1924, 2 studies aimed at separating nature and nurture by studying twins and adoptees. The focus of research in behavioural genetics is to identifies the genetic and environmental factors responsible for differences among individuals, not for the characteristics of a particular person. Role of genetic factors in psychology •

Genetic influences over the life span – general cognitive ability is that these influences continue to increase throughout the life span.

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Genes affecting multiple traits – eg. Same gene factor affecting anxiety also affect depression

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Identifying genes related to behaviour – eg. Huntington’s disease is caused by a single dominant gene