Individual 1 has an affected father, but the genotypes and phenotypes of individuals 1–4 are unknown. what is the probability that individual 1 is heterozygous? what is the probability that individual 3 is heterozygous? what is the probability that individual 4 is affected? 1/2; 1/4; 1/4 1/2; 1/4; 1/2 1; 1/4; 1/2 1; 1/2; 1/4 1; 1/2; 1/2