Genetics: study of variation b/w and among living things. Half from male parent and half from female parent (haploid) Phenotype: morphological, biochemical and behavioural properties of an organism resulting from a specific genotype and its interaction with environment. Genome: total amount of genetic material in a chromosome set (in humans or a diploid organism - one set of chromosomes) Sequencing a genome: working out the base sequence (adenine, thymine, cytosine, and guanine) of the dna. Humans have 2 genomes - nuclear genome and mitochondrial genome. Environmental factors (eg. alcohol during pregnancy -> fasd) Combination of genetic and environmental factors (most common) (eg. person inherits tendency to be tall, but poor diet during childhood causes poor growth) (eg. twins are genetically identical, but environment causes differences) Mother drinking alcohol during pregnancy -> deformed babies fasd. Huntington disease: change in dna on chromosome #4 (entirely genetic onset) Humans have 2 copies of huntington protein gene.