Monday, February 28, 2011

Science Experiment: Taste Gene Lab

This picture is just not behaving for me! No matter what I do I can't make it turn. Oh well. I hope you don't get a crick in your neck reading the label.

At our homeschool we are just not that into science experiments. We watch the videos, but rarely do the experiments ourselves. But today our AOP Monarch (6th Grade) Science 604: Molecular Genetics Unit had an experiment even this homeschool mom could handle: Taste Gene Lab.

We tested whether we had a dominant or recessive gene for the chemical phenylthiocarbamide (PTC) by chewing PTC taste paper strips.

These were our instructions (copied from our lesson):

First, be sure you are located near a trash can lined with a plastic bag.

2. Chew one of the taste strips of PTC. It must be moistened with saliva. To some people, the PTC tastes very nasty; to others, it is tasteless.

3. Spit out the taste strip after you have chewed it. Do not swallow the paper.

4. Note your taste reaction by clicking on the Report button below. The lifesaver mint is to remove any unpleasant taste from your mouth.

  • Describe your reaction to PTC. If you can taste PTC, indicate its flavor.
  • Do you have a dominant gene or recessive gene for tasting PTC?
  • If you can taste PTC, remember you may be TT or Tt.

We had a friend and his mom join our experiment. Mr. A went first, and definitely has the dominant gene. So does Mr. D. Missy made faces before the PTC paper strip went in her mouth, but then found out it had no taste: she has the recessive gene! When it was Mr. T's turn we concluded he has the weird (& dominant) gene, as he said: "Mmm.... It's bitter and delicious!" :)

Our friend A was next, and he has the recessive gene: the PTC paper strip had no taste for him. Little Miss spat our her PTC paper strip immediately and reached for the mints - another dominant gene. A's mom, Sennie & The Captain all had the dominant gene also, yuck!!!

Our conclusion was, based on The Punnet Square, that The Captain and Sennie both must have the hybrid dominant gene in order for three of our (biological) children to have the dominant gene, and one to have the recessive gene.

Very interesting stuff! I think everyone enjoyed this experiment. If anyone would like to try it, I have about 80 more strips I can mail to anyone who would like try it. Just leave me a comment with your email info or link.

I am linking this post to Hip Homeschool Hop, won't you join us there, also?

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Kiitos Soile-kääntäjäni, tässä käännös:

Me emme pahemmin välitä tieteellisistä kokeista kotikoulussamme. Me katsomme videot, mutta harvoin teemme itse mitään kokeita. Mutta tänään kotikouluohjelmassamme oli koe, jonka jopa tämä kotikoulu-äiti pystyi hoitamaan: Maku-geeni testi.

Me testasimme olisiko meillä vallitseva vai väistyvä geeni fenyylitiokarbamidi (PTC) kemikaalille, pureskelemalla PTC:n makuisia paperiliuskoja.

Nämä olivat oppitunnin ohjeet (kopioituna meidän oppitunnilta):

1. Ensiksi, ole lähellä muovipussilla vuorattua roskista (!)

2. Pureskele yhtä PTC:n makuista liuskaa. Sen on kostuttava syljestä. Jotkut ihmiset maistavat PTC:n hyvin pahana makuna; toisille se on mauton.

3. Sylje pois makuliuska pureskelun jälkeen. Älä niele paperia.

4. Ilmoita makureaktiosi “klikkaamalla” alla olevaa “Ilmoitus” painiketta. Mintun tarkoitus on poistaa mahdollinen epämiellyttävä maku suusta.
Kuvaa reaktiosi PTC:lle. Jos maistat PTC:n, kuvaile sen maku.
Onko sinulla vallitseva vai väistyvä geeni PTC:n maistamiselle?
Jos voit maistaa PTC:n, muista että voit olla TT tai Tt. (Tarkoittaa että on perinyt molemmilta, tai vain yhdeltä vanhemmalta.)

Meidän ystävä, ja tämän äiti ottivat myös osaa testiin. Mr A kokeili ensin, ja hänellä on ehdottomasti vallitseva geeni. Kuten myös Mr D:llä. Missy irvisteli ennen kuin maistoi PTC luiskaa, mutta huomasi sen olevan mauton: hänellä on väistyvä geeni! Kun oli Mr T:n vuoro tulimme siihen tulokseen että hänellä on outo (ja vallitseva) geeni, koska hän sanoi: ”Mmm... Se on hapan ja herkullinen” =)

Ystävämme A oli seuraavana vuorossa; ja hänellä on väistyvä geeni: PTC paperiliuska oli hänelle mauton. Little Miss sylki välittömästi PTC paperiliuskansa ja ojensi kätensä kohti minttuja – jälleen vallitseva geeni. A:n äidillä, Senniellä ja The Captainilla oli myös kaikilla vallitseva geeni, yäk!!!

Päätelmämme on, että The Captain ja Sennie ovat molemmat vallitsevan geenin kantajia (Tt molemmilla), koska kolmella meidän (biologisista) lapsista on vallitseva geeni, ja yhdellä on väistyvä geeni.

Hyvin mielenkiintoista! Luulen, että kaikki nauttivat tästä testistä. Minulla on noin 80 paperiliuskaa jäljellä, ja jos joku haluaa kokeilla tätä, niin voin postittaa niitä. Jätä minulle mailiosoite kommenttiin.


  1. Where did you get the strips? My girls and I would love to try this! Holler and I'll send you my mailing address. I'd be willing to send a couple bucks.

  2. I think I am actually with Mr. T on this one, I definitely tasted it when we did that in college, but it didn't taste bad. It was like very faint aspirin.
    But maybe I have the dominant gene and my strip was just a dud.

  3. Lana, we enjoyed it, and maybe will have to do more science experiments in the future :)

    Contessa Kris, I bought them from Amazon, but the smallest amount was 100 strips. I know I have a lot of kids, but we can't use all 100 :-D I'm happy to send you some, how many would you like to have? I just sent you an email (found your contact info on your blog).

    HarmlessColor, I have a theory about you two! You both have been trained to enjoy and eat strange things, and so can enjoy bitter PTC paper strips despite your dominant genes ;-)
    Or you had a dud. Making I should make Mr. T try again :)

  4. Oh, what fun. This experiment was part of the Monarch Curriculum? Wow, I was assuming it was only computer based learning. You are sweet to share!

  5. Neat experiment. Love some of the faces in those pictures.

  6. What fun, great collage of photos.
    I found you on the HHH today and I have got to say, you are living my dream. I look forward to reading more and living your life vicariously.

  7. TerriG, yes! The Monarch curriculum has a great science program, and you can separately buy a box of things you need to make the experiments. I'm embarrassed to confess this was the first on many we did ourselves..

    Thanks, Sarah! That stuff tasted so nasty. I was glad the camera was handy :)

    Lizzie, we are having fun with traveling and having adventures, but I have to say I'm one tired momma :-D We've been in New England now since Christmas, and we are starting to be ready for our next adventure :)

  8. Hi! I'm visiting from HHH. Thanks for sharing about the Monarch science curr, it looks fun! Your traveling adventure sounds awesome!

  9. Voi, kyllä mä sen voin huomenna kääntää, jos haluut :-)

    Oli muuten todella mielenkiintoinen koe, enpä ole ennen tuommoisesta kuullutkaan.

  10. what a blast! Sounds like such a fun way to learn about dominant and recessive genes. Love the pictures!!!

  11. Annika, Monarch has been a great curriculum! We've been reviewing our choices for next year, but I think we'll stick with Monarch :)

    Soile, arvaa oliko ongelmia yrittää kääntää :-D Annoin aika pian periksi..

    Jen, thanks to my son who has struggled through science this year we are working on the lessons together and really enjoying them. I have a feeling we'll try to do more science experiments too.

  12. Thanks for visiting my blog! SO neat that you're a RVing family! We love camping - we have a pop-up - but we dream about full-timing for a year to see the US.


  13. This made me smile because I could care less about the experiments. My kids obviously LOVE them & would do them all day if I let them. Fortunately I can let them do them on their own. I give them the supplies & let them figure it out. I love that they almost always can do it with out me & gives them a huge sense of accomplishment. Then I step in when it comes to photographing it all :)

  14. Jessy, we love RV'ing!! It's a great way to travel with kids. We'll be driving to FL next month and will miss our Mothership very much during the drive, but it will be waiting for us there to take some trips :)

    Chic Homeschool Mama, I like your thinking, lol!!! I'll have to come over to your blog and see what you use for science.

  15. We just did this in our coop science class about 2 weeks ago.It was fun to watch the kids react... or not which then shocked the kids that thought it tasted bad that the others couldn't taste it!

  16. quilt-n-mama, neat that you just did it too, recently :) It was a fun one!

  17. Jennifer HoneycuttJanuary 18, 2013 at 2:35 AM

    There are 6 of us, so I would LOVE some extras if you have them vs buying 100 myself! :-) GREAT idea! thanks so much!!!