Genetic crosses involving single genes (monohybrid inheritance) can be shown and examined using Punnett squares. The tall allele is dominant and is shown as T. The small allele is recessive and is ...

Characteristics are passed from parents to offspring. A gene is a small section of DNA that codes for a characteristic (e.g. eye colour). Alleles are different forms of the same gene, for example ...

Early use of the test cross was as an experimental mating test used to determine what alleles are present in the genotype. An organism's genetic makeup is called its genotype, and it reflects all ...