The punnett square was designed by Reginald Punnett to determine the probability of offspring to carry a particular trait. This is a very useful concept for reptile breeders in determining which geckos to pair up to produce offspring that will display a certain characteristic. Punnett squares do require a small understanding of genetics.

• A parent who displays a dominant characteristic (homozygous dominant) is labeled as 'AA'.
• A parent who displays a recessive characteristic (homozygous recessive) is labeled as 'aa'.
• A parent who displays a recessive characteristic but also carries the recessive characterisic (heterozygote) is labeled as 'Aa'.

The punnett square will display the probability of an offspring in showing a certain trait.

For example: If you cross two heterozygotes (carriers) the probability of having an albino (recessive) offspring is 1 in 4 or 25%.

Monohybrid Cross