In genetics, characters or traits are passed down from parents to offspring. These traits are determined by genes, which exist in different forms called alleles. Alleles can be either dominant or recessive.

Identifying Dominant Characters

A dominant character is a trait that is expressed even if only one copy of the associated allele is present. This means if an individual has one dominant allele and one recessive allele for a particular trait, the dominant trait will be visible.

A recessive character is a trait that is only expressed if two copies of the associated allele are present (i.e., the individual is homozygous for the recessive allele). If a dominant allele is also present, the recessive trait is masked.

Let's look at the given options and determine their typical inheritance pattern:

• Rolling tongue: The ability to roll one's tongue into a tube shape is generally considered a dominant trait. The inability to roll the tongue is recessive.
• Fingers with no hair: The presence of hair on fingers (specifically the middle segment) is typically considered a dominant trait. The absence of hair on fingers is recessive.
• Attached ear lobes: Having attached ear lobes is generally considered a recessive trait. Free ear lobes are dominant.
• Folding tongue: While related to tongue abilities, 'folding tongue' isn't as commonly used as a standard example of a simple dominant/recessive trait compared to 'rolling tongue'. However, 'rolling tongue' is well-established as a dominant example.

Based on typical human inheritance patterns often taught in introductory genetics, the ability to roll one's tongue is a widely cited example of a dominant character.

Therefore, out of the given options, Rolling tongue is a dominant character.