Heredity

Six topics on how traits pass from one generation to the next. Meiosis and how two divisions halve the chromosome number to make four genetically varied haploid gametes, the two sources of genetic diversity — independent assortment of homolog pairs and crossing over between them, Mendelian genetics where genotype and phenotype are distinct and Punnett squares, the rules of probability, and the chi-square test predict and test offspring ratios, non-Mendelian patterns like incomplete dominance, codominance, and multiple alleles that break the simple dominant-recessive picture, the environment that interacts with genotype so genes do not fully determine phenotype, and chromosomal inheritance where nondisjunction produces aneuploidy and sex-linked traits follow their own patterns.