The Ability to Roll the Edges of the Tongue Upward

Multiple Choice

The ability to roll the edges of the tongue upward in a U-shape is considered to be an inherited trait.The standard assumption is that tongue-rolling is a dominant allele at a single gene locus.Which of the following would cast doubt on this assumption? Select all that apply.

A) A student who can roll his tongue has both a mother and father who cannot.
B) In a large research study,the majority of tongue-rollers were male.
C) A research study with 1,000 participants reports that most non-tongue-rollers can learn to roll their tongues.
D) A student who cannot roll his tongue has both a mother and father who can.