OK, we know that your cactus is aa. What does this tell you about it's parents?

Your cactus has a genotype of aa and it must have received one a from the female parent and one a from the male parent. If one of those parents had a phenotype of arms that are the same length, it must also have had one A allele, so what must it's genotype have been?

Return to the question page to select the correct answers.

You know that the genotype of your cactus is aa and that this results in a phenotype of different length arms. You also know that to have arms of the same length, a cactus must have a genotype of either AA or Aa. So, the simplest way to determine the genotype of your neighbor's cactus is to do a punnett square using each of the possible genotypes and find out which one produces some offspring with arms the same length and some with arms of different lengths. A blank punnett square has been provided below for you to use.

Now return to the question page to select the correct answers.