Punnettwho devised the approach. Previous Topic. It is important to understand the terms "heterozygous", "homozygous", "double heterozygote" or homozygote"dominant allele" and "recessive allele" when using the Punnett square method.
Show the possible offspring for a cross between two pea plants that are both heterozygous for this trait. Spanish 2 Language Live!
For this example, let us define "A" as being the dominant normal allele and "a" as the recessive abnormal one that is responsible for cystic fibrosis. All rights reserved. What phenotypes are predicted by this square? Inheriting just one copy of such a dominant allele will cause the disorder.
Answer: The father. The ratio of the phenotypes istypical for a monohybrid cross. However, some traits are not inherited with the simple mathematical probability suggested here.
One parent is heterozygous Yy and the other is homozygous yy, the completed Punnett Square would look like the one on the right. The traits are long tail sshort tail Sbrown fur B and white fur b. It does not matter which parent is on the side or the top of the Punnett square. It is conventional in genetics to use capital letters to indicate dominant alleles and lower-case letters to indicate recessive alleles.
The Punnett square is a tabular summary of possible combinations of maternal alleles with paternal alleles.
Is it the father or the mother? Next Topic. For multiple traits, using the "forked-line method" is typically much easier than the Punnett square.