Determination should include

evaluation of the breeding animal
probability of a given trait in the offspring
difference between genotype and phenotype
difference between recessive and dominant alleles
difference between homozygous and heterozygous
use of a Punnett square and the product rule to calculate the probability of two or more independent events occurring and predicting frequencies of fertilization events (e.g., for independent events X and Y, the probability [P] of them both occurring [X and Y] is P[X] multiplied by P[Y])
use of the sum rule to calculate the probability that any one of several events will occur (e.g., for mutually exclusive events X and Y, the probability [P] that one will occur [X or Y] is P[X] + P [Y]).

Process/Skill Questions:

What is the difference between a genotype and phenotype?
What is a Punnett square?
How can a Punnett square be used to predict the probability of an offspring having a particular genotype?
What are the probabilities for F1 genotypes and phenotypes if a homozygous dominant brown horse is crossed with a heterozygous brown horse (tan is the recessive color)?
What genetic tests should be run when breeding animals and what do the results mean?

Teacher Resources:

Basic Horse Genetics, Alabama Cooperative Extension System
Horse DNA Collection, Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis