AP BIOLOGY

Detailed explanation-1: -If the test cross results in any recessive offspring, then the parent organism is heterozygous for the allele in question. If the test cross results in only phenotypically dominant offspring, then the parent organism is homozygous dominant for the allele in question.

Detailed explanation-2: -Answer and Explanation: The test performed is a test cross. The test cross determines if the plant is homozygous or heterozygous. In a test cross, the plant under examination is crossed with a homozygous recessive plant for that trait, and the phenotypic ratio of the first generation offspring is observed.

Detailed explanation-3: -A test cross can be used to determine whether an organism with a dominant phenotype is homozygous or heterozygous. In a test cross, a parent with a dominant phenotype but unknown genotype is crossed with a recessive parent.

Detailed explanation-4: -The unknown genotype can be determined by observing the phenotypes of the resulting offspring. If crossing the unknown dominant phenotype (PP or Pp genotype) individual with the recessive phenotype individual produces only dominant phenotypes (no recessive), then the unknown individual is homozygous dominant.