Single gene traits

Tongue rolling The ability to roll your tongue is dominant, while non-rolling is recessive.

Free Ear Lobe Having a detached/free ear lobe is a dominant trait. Having an attached earlobe is recessive.

Hand Clasping Clasp your hands together. Notice whether your left or right thumb is on top. If your left thumb is on top, you have the dominant trait. If the right the thumb is on top, you have the recessive trait.

Hitchhikers thumb Straight thumb: Dominant Hitchhikers thumb: Recessive

Bent little finger Place the palms of your hands together gently, side by side with your palms facing towards you. Dominant: Last two joints of finger bend away from each other Recessive: Little fingers are straigaht

Widow’s peak Dominant: Widow’s Peak Recessive: Straight Hairline

Dimpled chin Dominant: Chin Cleft Recessive: Absence of Cleft

Mid-digital hair Hair on the middle segment of finger: Dominant No hair: recessive

Pigmented Irises When a person is recessive for this gene, they have no pigment in the front part of the eyes and a blue layer at the back of the iris shows through, resulting in blue eyes. A dominant gene causes pigment to be deposited in front of the iris, masking the blue to various degrees. Dark pigment (green/brown/black): Dominant No pigment (grey/blue): recessive

Dimples Dimples: Dominant No Dimples: Recessive