Question

tongue rolling is a dominant trait, so rollers are dominant and non rollers are recessive fill in the blanks with
oller\ or
on roller\
apply your new knowledge to the twins scenario.
brown hair is recessive, red hair is dominant. provide the genotype (alleles/letters) for the phenotype, use the letter r.
freckles are dominant, no freckles are recessive. provide the genotype (alleles/letters) for the phenotype, use the letter f.

Explanation:

• Tongue - rolling trait:
• For the genotype \(TT\), since the dominant allele \(T\) is present (homozygous dominant), the phenotype is “roller”.
• For the genotype \(tt\), as there are only recessive alleles (homozygous recessive), the phenotype is “non - roller”.
• For the genotype \(Tt\), with the dominant allele \(T\) (heterozygous), the phenotype is “roller” (the dominant allele masks the recessive one).
• Hair color trait (where red is dominant \(R\) and brown is recessive \(r\)):
• For red hair (phenotype), if it is homozygous dominant, the genotype is \(RR\). If it is heterozygous, the genotype is \(Rr\).
• For brown hair (phenotype), since it is recessive, the genotype must be \(rr\) (homozygous recessive).
• Freckles trait (where freckles \(F\) is dominant and no freckles \(f\) is recessive):
• For freckles (phenotype), if it is homozygous dominant, the genotype is \(FF\). If it is heterozygous, the genotype is \(Ff\).
• For no freckles (phenotype), since it is recessive, the genotype must be \(ff\) (homozygous recessive).

Answer:

• Tongue - rolling:
• \(TT\): roller
• \(tt\): non - roller
• \(Tt\): roller
• Hair color:
• Red Hair: \(RR\), \(Rr\)
• Brown Hair: \(rr\)
• Freckles:
• Freckles: \(FF\), \(Ff\)
• No Freckles: \(ff\)