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Gene: a region of DNA that instructs the cell on how to build protein(s). As a human, you usually get a set of instructions from your mom and another set from your dad... more
Inheritance: genetic information passed down from a parent.
Phenotype: the appearance of an individual that results from the interaction between their genetic makeup and the environment. Phenotypic trait... more
Trait: a characteristic of an organism that can be the result of genes and/or influenced by the environment. Traits can be physical like hair color or the shape and size of a plant leaf. Traits can also be behaviors such as nest building behavior in birds.

**Some of the content on this page is out of date, please pardon us while we update it for accuracy.**

Below is a list of phenotypes easily identified in humans that follow the pattern of Mendelian inheritance. Look at yourself in the mirror to see if you carry the dominant or recessive alleles for these traits.

Mendelian Traits In Humans 

Cleft chin (dominant)      Chin without a cleft (recessive)
cleft chin
Wikimedia - cutehappybrute

 
 
chin without cleft
Wikimedia - David Tribble

 

Cheek dimples (dominant)

  No cheek dimples (recessive)
Cheek dimples
Wikimedia - C. Szeto

 
 
no cheek dimples
Ask A Biologist - Jacob Mayfield

 
Free (dominant) earlobes   Attached (recessive) earlobes
unattached earlobe
Wikimedia - David Benbennick

 
 
attached earlobe
Wikimedia - Covalent

 
Face freckles (dominant)   No face freckles (recessive)
face freckles
Wikimedia - Loyna

 
 
no face freckles
Wikimedia - David Tribble

 
No Hitchhiker's thumb (dominant)   Hitchhiker's thumb (recessive)
hitckhiker's thumb
Wikimedia - manic rage

 
 
normal thumb
Wikimedia - drozd

 
Widow's peak (dominant)   No Widow's peak (recessive)
widow's peak hairline
Wikimedia - ccupload

 
 
flat hairline
Wikimedia - ccupload

 

The expression of traits, however, is often far more complicated than in those listed above or those which Mendel observed in his garden. Sometimes tens, or even hundreds of genes can play a role in just one trait! In some cases, genes can block or exaggerate processes in the cell which change the visible phenotype. In other cases, environmental factors such temperature, light, and nutrient levels influence the development of a phenotype. Below is a list of traits in humans involving interaction between multiple genes.

Non-Mendelian Traits in Humans

Eye color       
black eyes
Wikimedia - marc davis

 
 
brown/black eyes
Wikimedia - pranav yaddanapudi

 
blue eyes
Wikimedia - D. Sharon Pruitt

 
 
green eyes
Wikimedia - Pedram Amiri

 
Hair Color    
red hair
Wikimedia - Stephen Key

 
 
black hair
Wikimedia - Marc Davis

 
brown hair
Wikimedia - Alvesgaspar

 
 
blonde hair
Wikimedia - Nicolas Genin

 
Ability to roll tongue    
rolled tongue
Wikimedia - Gideon Tsang

 
 
not rolled tongue
 

References:

List of Mendelian traits in humans. In Wikipedia. Retrieved July 20, 2010, from https://en.wikipedia.org/wiki/List_of_Mendelian_traits_in_humans

Additional images via Wikimedia. Close up of iris by Petr Novák.

Read more about: Solving a Genetic Mystery
You may need to edit author's name to meet the style formats, which are in most cases "Last name, First name."
https://askabiologist.asu.edu/mendelian-traits-humans

Bibliographic details:

  • Article: Human Traits
  • Author(s): Dr. Biology
  • Publisher: Arizona State University School of Life Sciences Ask A Biologist
  • Site name: ASU - Ask A Biologist
  • Date published: 20 Jul, 2010
  • Date accessed:
  • Link: https://askabiologist.asu.edu/mendelian-traits-humans

APA Style

Dr. Biology. (Tue, 07/20/2010 - 11:35). Human Traits. ASU - Ask A Biologist. Retrieved from https://askabiologist.asu.edu/mendelian-traits-humans

American Psychological Association. For more info, see http://owl.english.purdue.edu/owl/resource/560/10/

Chicago Manual of Style

Dr. Biology. "Human Traits". ASU - Ask A Biologist. 20 Jul 2010. https://askabiologist.asu.edu/mendelian-traits-humans

MLA 2017 Style

Dr. Biology. "Human Traits". ASU - Ask A Biologist. 20 Jul 2010. ASU - Ask A Biologist, Web. https://askabiologist.asu.edu/mendelian-traits-humans

Modern Language Association, 7th Ed. For more info, see http://owl.english.purdue.edu/owl/resource/747/08/
Close up showing a blue colored eye with hazel flecks

Eye color is not a Mendelian trait because it is controlled by several genes, in addition to other factors.

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