Name:____________________________________

Human Genetics

Instructions: As a class, go over each of the following traits and determine how many in the class exhibit the phenotype. Also view the presentation that shows pictures of these traits at Human Genetic Traits via docs.google.com.

Trait Description

Yourself

Class numbers

Ear points (Darwin's Point)

    
Tongue rolling    
Plays a sport    
Attached earlobe    
Plays an instrument    
Hitchhiker’s Thumb    
Upturned Nose    

Left-Handed

    

Freckles

    
Bent little fingers    
Curly hair    
Short big toe    
Eye Color (blue?)*    
Straight Hairline (not widow's peak)    

Chin dimple or cleft

    

Hand clasping, left over right thumb

    

Hair on middle joints of fingers

    

G.P.A. of 4 or above (A students)

    

Ring finger longer than index finger**

    

Likes broccoli

    

Arm folding ­ fold arms across stomach, is left on top?

    

Popularity (how many consider themselves popular)

    

Nearsighted

    
Gap between front teeth    
P.T.C Taster ***    

thumbwidows peakshort big toeearlobes

Teacher Notes: Many of the traits do not have a clear genetic cause, such as intelligence or musical ability. Some traits follow basic dominance and recessiveness rules, and others are controlled by multiple alleles, such as eye color. The survey is a fun way to talk about genetics, and make observations about individuals in the classroom. The powerpoint presentation at docs.google is also a good resource to show photos of the various traits.

*Blue eyes - When a person is homozygous for a recessive gene no pigment is deposited in the from part of the eye and a blue layer at the back of the iris shows through.  A dominant gene, allows pigment to be deposited which masks the blue color.  Other genes are responsible for the type and amount of this pigment leading to various shades of brown, hazel, green and other colors.

**Ring Finger - generally, this trait is determined by your sex. Males tend to have a longer ring finger, females have a shorter ring finger.

***P.T.C. Taster - this requires test strips, available from biological supply companies( Carolina or Wards ). The strips are soaked in a chemical that only some people can taste, depending on their genotype.

Image Credits: Made from photographs, using picnik.com