Option 1, 'the physical traits a person has', refers to phenotype, not a karyotype. Option 2, 'a method of identifying crossover events', relates to genetic recombination, not a karyotype. Option 3, 'all the possible gametes a person could produce', pertains to genetic variation, not a karyotype. Option 4, 'a list of all the genes a person carries', describes a genotype, not a karyotype.