PSB-2000 Lecture Notes - Lecture 2: Methyl Group, Cytosine, Epigenetics
Document Summary
Human traits: nature or nurture: an interaction of nature and nurture. Direct observation of natural selection: finches of the galapagos islands changed dramatically after a single season of drought. Evolution and behavior: physical features contribute to fitness. A more fit organism can survive & reproduce in the current environment: so do behaviors. Ability to find food, avoid predation, etc. Most human phenomena are heritable: can be transmitted from parent to offspring. The nucleus of every human cell contains 46 chromosomes: 22 pairs of autosomal chromosomes, plus 2 sex chromosomes. Xy (male: each chromosome consists of dna & histone proteins, karyotype- the number and appearance of the chromosomes. The dna portion of the chromosome contains genes: sequence of dna = gene. Sometimes genes overlap on a stretch of chromosome: chromosomes come in pairs, so genes come in pairs. The genes you have for a trait are your genotype: a gene contains information on hereditary characteristics.
