If there are 2 alleles at a locus, p and q represent their frequencies: p + q = 1: the hardy-weinberg model states that allele and genotype frequencies remain constant, genotype frequencies: p2, hardy-weinberg equilibrium. Chapter 1: introduction: overview: the study of life, levels of organization, emergent properties: the whole is greater than the sum of its parts, ecosystems communities: deer and plants populations: herd of deer . Organism: one deer organs and organ systems tissues cells organelles. All of the descendants: parsimony is used to infer a phylogeny, maximum parsimony: the simplest (evolutionary change) is the most likely; given a set of alternatives. 5" 3" directions (antiparallel) arrangement: the nitrogenous bases in dna pair and h-bond: adenine (a) with thymine (t), guanine (g) with cytosine (c); complementary base pairing (also in trna) Chapter 4: cells and organelles: cells: the fundamental units of life.