======PTC Genetic Taste Test======


<WRAP right box>
**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
\\
**Categories:** {{$demo.categories}}
\\


**Alternative titles:** Bitter Taste Receptors and PTC
</WRAP>

====Summary====                   
{{$demo.summary}}



====Procedure====  
  - Provide students with PTC paper strips (or similar safe substitutes used in genetics education).
  - Have each student place the strip on their tongue for a few seconds and record their perception (bitter, slightly bitter, or no taste).
  - Collect class results and group individuals as tasters, weak tasters, or non-tasters.
  - Discuss inheritance patterns, noting that tasting is a dominant trait.
  - Extend by comparing results to population averages (about 75% tasters, 25% non-tasters).
  - Explore environmental and physiological factors (e.g., dry mouth, prior food intake) that may influence results.



====Links==== 
Do you have the bitter taste gene? | Science-U - wpsu: 
{{youtube>fqVSNiWDTQU?}}\\


📄 PTC The Genetics of Bitter Taste - Learn.Genetics: [[https://learn.genetics.utah.edu/content/basics/ptc/]]\\


====Variations====
  * Compare PTC tasting with thiourea or PROP (propylthiouracil), other bitter-tasting compounds used in genetics studies.
  * Investigate correlations between PTC tasting ability and food preferences (e.g., broccoli, coffee, dark chocolate).
  * Conduct a family survey to create a pedigree chart and analyze inheritance.
  * Relate findings to evolutionary biology by discussing survival advantages of bitter taste detection.



====Safety Precautions====
  * Use only commercially prepared PTC paper intended for classroom use.
  * Ensure students do not swallow the paper; it should be briefly tasted and discarded.
  * Provide water for rinsing mouths after tasting.
  * Screen for allergies or sensitivities before the activity.




====Questions to Consider====
  * What does it mean genetically if someone can taste PTC? (They carry at least one copy of the tasting allele, T.)
  * Why might non-tasters still exist if tasting bitter compounds is advantageous? (Heterozygotes may have selective advantages, or non-tasters may detect other bitter compounds.)
  * How does PTC tasting demonstrate Mendelian inheritance? (Tasting is a dominant trait; non-tasters have two recessive alleles, tt.)
  * What evolutionary purpose does bitter taste perception serve? (It helps avoid toxic plants and chemicals.)
  * How might PTC tasting ability influence health choices? (Strong tasters may avoid bitter vegetables or tobacco products.)