Biology Forums - Study Force

This pedigree traces tongue rolling in a family. Filled in circles and squares represent the ability to roll the tongue. The ability to roll your tongue is controlled by a dominant allele; people with the recessive allele cannot roll their tongue. Identify the phenotypes and genotypes of all the people shown in this pedigree. Enter phenotypes as roll or not. Enter gentoypes as RR, Rr or rr.

I-1 phenotype is ______ I-1 genotype is ______
I-2 phenotype is ______ I-2 genotype is______
II-1 phenotype is ______ II-1 genotype is ______
II-2 phenotype is ______ II-2 genotype is _______
II-3 phenotype is ______ II-3 genotype is ______
II-4 phenotype is ______ II-4 genotype is ______
III-1 phenotype is _____  III-1genotype is ______
III-2 phenotype is _____  III-2genotype is ______
III-3 phenotype is ______ III-3 genotype is ______
III-4 phenotype is ______ III-4 genotype is ______
III-5 phenotype is ______ III-5 genotype is ______

My problem is do you need two dominant alleles (RR) to have that ability? I assumed so.

RR is tongue rolling
Rr and rr is non-tongue rolling

which is phenotype and genotype?

Genotype is RR, Rr, etc.

Which is the phenotype? What do I fill in for phenotype?

RR and Rr (ability to role)
rr (inability to role)

What's highlighted is the phenotype

isn't RR for rolling tongue
and Rr and rr is non rolling?

or are you right?

It says "people with the recessive allele cannot roll their tongue."

so I think I am right on this

Does this mean that your pedigree diagram is labelled incorrectly?
If the genotype RR and Rr result in the phenotype of rolling tongue, and only rr is non-rolling. Your diagram shows white squares with dominant alleles, shouldn't they be black as well if you were correct?

So how should it be?

:)

Thank you so much!