The ability to roll the tongue into a tube is a single-gene dominant trait governed by the R The recessive allele for lacking the ability is r. A woman who can roll her tongue has a father who cannot. What is her tongue-rolling genotype?RRRrrreither A or Bcannot tell from the information provided

Mendel's Law of dominance : A dominant trait like rolling the tongue into tube is controlled by a dominant allele 'R' , it can show its character in the phenotype ,both in homozygous and heterozygous condition. A recessive allele like 'r' will show its character only in homozygous recessive condition. In heterozygous, dominant allele will suppress characters of recessive one in the phenotype. Rr is the correct answer Explanation for the correct answer A woman who can roll her tongue has a father who cannot, it means her father must be homozygous recessive for lacking the ability to roll the tongue into tube. His genotype must be rr to show its recessive character in the phenotype. The woman got one recessive allele from her father and one dominant allele from her mother ,that's why she can roll the tongue into tube which is a dominant trait. Hence genotype of the woman would be heterozygous ( Two different alleles) that is Rr.Explanation for the incorrect options : RR would be incorrect because, it is homozygous dominant genotype , to have this type of genotype ,both parents must have dominant alleles, but here according to the que father has recessive trait with homozygous recessive state. rr would be incorrect because the woman has dominant phenotype of rolling the tongue , rr results in recessive character in the phenotype. Hence , Rr ( heterozygous allelic condition) would be her tongue-rolling genotype .