A cross between two true-breeding parents differing in one characteristic is called a:

1. The prefix mono- counts the characteristics being followed. 2. When fertilisation occurs between two true-breeding parents that differ in only one characteristic, the process is called a monohybrid cross. 3. The resulting offspring are monohybrids. 4. Mendel performed seven monohybrid crosses involving contrasting traits for each characteristic. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 12 'Mendel's Experiments and Heredity', sections 12.1-12.3_