What is meant by the term "true breeding"?

Individuals, who, when bred to others of the same genotype, produce only offspring of that genotype, are called true breeding. In other words, homozygous individuals (AA, aa) are true breeding when bred among themselves, while heterozygotes (Aa) are not.

Previous question:	How does a dominant trait differ from a recessive trait?
Next question:	What is a hybrid?

---