Genetic Traits Activity


Finding Your Genetic Match


Have you ever noticed that brothers or sisters often look alike?  Their inherited traits are what make their physical appearance so similar. An inherited trait is a particular genetically determined characteristic that distinguishes a person. The traits of children are determined by the traits that  are passed on from their parents. Some traits are obvious in a family — a child’s nose is shaped like their mother’s nose, but some traits are less obvious. You may have similar traits to many of your classmates even though you are not related to them. Some examples of often un-noticed human traits are the ability or not to roll your tongue, attached or unattached earlobes, dimples or freckles, naturally curly or straight hair, hitchhiker’s or straight thumb, straight or widow’s peak hairline, smooth or cleft chin, or colorblindness or normal vision.

There are numerous traits in humans, but some traits occur more frequently than others.  Between 70-90% of the human population have free-hanging earlobes, can roll their tongue,  are right-handed, and can taste a chemical called PTC.  These traits are called high frequency traits.


Students will determine the presence of certain high frequency traits in themselves & their classmates.


Genetic Inventory sheet with pictures, paper, pencil, PTC taste strips.


  1. Identify which of the following 10 human traits you have by placing a check mark beside that trait.
  2. Compare the traits you have with other students in the classroom and find the student you most closely match.



Human Trait Inventory
Tongue Roller
Non-Tongue Roller
Attached Earlobes
Unattached earlobes
No Dimples
Widow’s Peak
Straight Hairline
Left Thumb on top when Hands Crossed
Right Thumb on top when Hands Crossed
Hair on mid-digit of hand
No hair on mid-digit of hand
Bent little finger
Straight little finger
Second toe longer than big toe
Second toe not longer than big toe
Can Taste PTC
Can Not Taste PTC
Vulcan (Fingers spread 2 by 2)
None Vulcan
Class Match:




Tongue RollerNon RollerDimplesNo Dimples
Attached EarlobesUnattached EarlobesWidow’s PeakStraight Hairline
Longer Second ToeShort Second ToeBent Little fingerHitchhiker’s Thumb
Attached Ear lobes (left)
Unattached ear Lobes (right)
“VULCAN” or No “VULCAN”DimplesRight/Left Thumb on top