A so-so quiz on DNA

February 5, 2016 • 8:30 am

Reader Diane G. called my attention to A Quiz on DNA at Now I Know quizzes.  Some questions were easy, others were harder, and one question is really, really dumb. You get 8 minutes to answer 19 questions.

As a geneticist of sorts, I better have gotten them all, and I did (see below; click on screenshot to go to quiz), but for a few questions I had to enter several answers before I got the right one. (You can’t proceed until you get a question right, but you can give up and start all over again.)

The questions are mostly on DNA structure, and I don’t expect non-scientists to get all of them.

Try it yourself and report the results in the comments. I bet you can figure out what the dumbest question is, but that one’s not so easy to answer!

Screen shot 2016-02-04 at 3.51.00 PM

74 thoughts on “A so-so quiz on DNA

      1. It wouldnt take “DNA polymerase” but then showed that that actually was the answer (which I knew it was) but I had to quit to see it. Otherwise I scored perfect up to that point.

    1. It’s a god example of how to not design an quiz/ flashcard application. I gave up after putting in about 6 different spellings of “deoxyribose nucleic acid” and I still can’t figure out what precise incantation it wanted. Or should I have been sacrificing a virgin?

        1. I got that right, but got stuck on the ‘subunits’ question. Tried ‘thymine adenine cytosine guanine’ but that wasn’t right.

          I’m not a biologist!

          I agree the format of the quiz is bad, it should let you make a mistake and carry on with the next questions.


      1. Same here! I’m surprised it wasn’t programmed to take common variations like that! It would, for example, accept either “46” or “23 pairs” for number of human chromosomes. (I wonder if those of us of a certain era were more likely to learn deoxyribose?)

        When I was working on enzymes they were commonly described in a couple of ways. E.g., where we used Glutamate Oxaloacetate Transaminase, other labs preferred Glutamic Oxaloacetic Transaminase…ditto for other enzymes…Then there was PGI vs. PHI…and many more…

        1. Yes, I typed in ’46’ (which surprised me, because I didn’t know I knew that) and it promptly said ’23 pairs’.

          My knowledge ran out shortly after that…


            1. mageDalton – weighs on the order of a million atomic mass units (12C weighs 12 amu = 12 Dalton). So a carbohydrate molecule which is (CH2O)n weighs 30 Dalton per unit, and a 30,000-strong polymer is around a megaDalton. (Actually, poor example ; cellulose goes up into the 10,000 region, but I don’t see references to 30,000. better example : a base pair of DNA is around 460dalton (average of G, C, A and T, plus 2x ribose), so a 2000 base pair (~600 codons) length of DNA is around a megaDalton.
              The rate of movement of biopolymers in chromatographic plates is strongly controlled by the MW, so for set conditions of solvent, pH, etc, you could scale your “blot-o-grams” (they’re more general than just DNA analysis) in MDa on each axis.
              Haven’t had to trot that lot out for 30 years, but I have to teach people “chromatography for beginners” several times a year, sometimes several times a month.

    2. It struck me that it was wanting you to use specific phrases from a course of instruction. A course that we hadn’t been given.

  1. What is the purpose of DNA? When I say replication of genetic information it does nothing… what is the purpose of anything? Nothing has purpose!!!!

        1. A zillion variations on “Transmit information” or “encode information” or “provide means to duplicate genetic information” would not be accepted, so I quit. I fucking hate that shit.

        2. A zillion variations on “Transmit information” or “encode information” or “provide means to duplicate genetic information” would not be accepted, so I quit. I fucking hate that shit.

        3. A zillion variations on “Transmit information” or “encode information” or “provide means to duplicate genetic information” would not be accepted, so I quit. I fucking hate that shit.

    1. Yeah, that is also a frustrating aspect of this quiz. Using the correct key word. For example, on that question as soon as you type the word “code” it accepts that you answered correctly and fills in the rest of the answer for you.

      I was about to break my keyboard before I figured that out. I kept typing variations of “encodes instructions for the development and function of organisms” and nothing was happening. By chance I finally typed “code” as I began to enter the smartass answer “code of life,” and boom.

    2. Oh, gawd, I tried a million different stabs at that one. It finally accepted something, I forget what. I thought it might just be feeling sorry for me by then…

      1. Sometimes ignorance is bliss. ‘Umm, something to do with genetic thingies maybe?’
        (Types in ‘genetic’ which it *immediately* accepts)


  2. I didn’t quite beat your time. 4:28. The challenge sometimes in quizzes like this is knowing all the exceptions to the rules. Not all prokaryotic DNA is “a ring”; some spirochetes, Borrelia in particular, have linear chromosomes with hairpin ends. I spent a few seconds shouting at the monitor…

  3. I am usually good at these kinds of tests on just about any subject, but that one is hard. I made it to 12/19 before running out of time.

    Part of the problem was that I could not find a way to move on to another question and I spent a lot of time trying to figure out a way to do that. Apparently you have to answer each question in order and can’t move to the next one until you enter the correct answer.

    1. Hmm, well. After reading Jerry’s comment saying that you can pass on questions if you want I feel stupid. Cuz I went and took the test again and still couldn’t figure out how to pass on a question.

      In any case, I think my knowledge of DNA hits its limit at question 14. On my second try I pretty quickly and easily made it to 13 but 14 is beyond this non-biologist.

      1. The big issue for me–even as an English prof–is the spelling of scientific words. I about spanked my keyboard to death.

            1. No worries. No way you could have known. Jerry has god like editing powers within the WEIT universe. Science can not, even in principal, detect him unless he wills it.

    2. Yeah, I hated not being able to skip ahead, then return to the stumbling blocks. The first time I tried it I got stuck about a third of the way in or so…the second time somewhat farther. Thus it took me three tries to finish within the time limit.

      1. But the test is designed that way because the questions are supposedly progressively more difficult so you want to see how far you PROGRESS in “difficultiness” of the questions not just a total score.

  4. “You got 84% correct”; I gave up at the first who paired bases correctly. Sigh, history of science…

    1. 84% also. I cheated by googling to get helicase, and ran out of time looking up Chargaff, but a lot of my time ran down while reading comments here…

      1. I was one vowel away from getting 17/19 before running out of time. I was typing the end of his name as -off and -ov and wondering for a minute why this isn’t working. 😀 But 16 is still something I’m happy with since I’m not in any way in a related field.

  5. Got it. But it was not always possible to know what word it wanted for a correct answer. ‘Circular’ versus ‘Ring’, for example.
    I thought it was ok to ask what is the purpose of DNA, as long as one applies the weaker meaning of purpose rather than expecting it to mean that DNA has a ‘higher’ purpose like to make cats.
    I think a dumb-ish question was to ask what kind of RNA is coded for in DNA. The answer there is that it potentially codes for ALL kinds of RNA, but that was not what it wanted.

    1. I agree, the idea that DNA only codes for mRNA is erroneous, and a pernicious error at that. Reminds me of the argument that I had with one of my fellow instructors about whether DNA is transcribed only to mRNA, or whether the process of copying DNA into tRNA and rRNA also counts as transcription. Of course, it’s all transcription. I wonder how many university students he misinformed over the years until I corrected him.

  6. I was doing well for a lay person — eight right — but I kept typing in the wrong box, and when I wanted to skip a question (the shape of dna in a prokaryote) the f-ing thing started over. dumb set up.

    The “purpose of dna” has to be the dumb question you reference. Not bad for an English major?

  7. Oh, for fuck’s sake. If I give up one one (prokaryotic shape) it ends the damn exercise. This thing’s a zero.

  8. I did genetics and got stuck on two questions.

    I couldn’t remember who discovered the A=T G=C pairing rule. Not remembering that isn’t particularly important as long as you remember the pairing rule though.

    And the second one; that dumb “purpose of DNA” question. I had no idea what they wanted from it. I tried a bunch of things, from blueprint of the cell, storage of genetic information, all those sorts of things. It does a lot more than just code for proteins though, so that bugs me the most.

    Other than those two, it was a breeze.

  9. 19/19 with 5:42 left on the clock.

    Not bad for a mere high school biology teacher. 😉

    But, yes, it was odd figuring out what they wanted you to type for some of the questions. For the (I presume) one, I put in “storing genetic information” and it didn’t take, but then I started typing “genes” and it took that. Odd. “Ring” instead of “Circular” also seemed odd to me.

    1. “Mere” nothing – teaching is hard. You trounced me by a few minutes (FWIW I’m a molecular geneticist). Chargaff took forever to come to me. 🙂

      1. I knew Chargaff, but still had to Google the answer because I misrembered the spelling as Chargoff and thought perhaps I didn’t remember the correct person after all. And as someone else stated, that’s a history question, not a biology question. I got 100% on first try with 1:51 left. I had the most trouble figuring out how to word the first few answers to get it to recognize that I knew the answer.

  10. had to look up Chargaff, otherwise I knew them all, although I had to run the alphabet to get my brain to cough up ‘Okazaki’.

  11. 18/19 – slightly embarrassing for someone with a PhD in genetics!

    My excuse was the the one I got wrong was the ‘What scientist discovered that A=T and C=G?’ question.

    To me that’s more related to the history of genetics than genetics as a scientific discipline.

    It’s good to be aware of the general history of your field, but if I wanted to memorise a long list of names and dates I would have become a historian.

    It annoys me greatly when you do a “science” quiz and half the questions are ‘who discovered x’ and ‘when was y discovered’.

    It’s like having a history quiz on the Spanish colonization of South America and then asking for the atomic number of the gold they took!

    1. Now that you mention it, I will admit I did cheat (Google) on that one. But I assuaged my conscience by the faint bell of recognition it rang once I saw the right answer; and also because “history” questions like that shouldn’t count anyway. 😀

  12. 14/19 … not bad for someone whose worst subject in high school was biology 🙂

    Though a couple of them were sheer guesswork …

  13. So I clinked on the link and the first thing I saw was an image of a left-handed double helix! Epic fail!!!

  14. I had to give up because it just didn’t come to my mind that DNA has only a single purpose namely to “serve as genetic code for protein synthesis”. However, could anything better be expected from a DNA quiz headed by a left-handed DNA molecule.

  15. This was a test for patience(how many times you were willing to start over to get a perfect score), short-term memory, and touch-typing skills.

    I eventually got 19/19 with 6.71 remaining on the clock. How many tries? I ain’t tellin’.

  16. 3:18 to complete. Took a few guesses on the “information” one. The worst question is the one asking what sort of RNA is directly encoded by DNA, because all of them are. I have no idea why they settled on mRNA – possibly due to post processing? If so, then mRNA is also out because of splicing and the answer should be hnRNA.

    1. That one was “gettable” via the “first one that comes to mind” strategy. Another example wherein too MUCH knowledge is a dangerous thing!

    2. I think (as a high school science teacher) they take mRNA to be the answer because “DNA – mRNA (with tRNA help)- protein” is the sequence taught in high school for transcription/translation of DNA to protein. They are trying to get you to channel your inner grade 11 biology self.

  17. I was pretty pleased with myself! Half a bottle of Brunello di Montalcino and I ended up 19/19 with 2:54 left. High school science teacher. I think we do ok with this because we tend to teach the simpler concepts year in and year out. All you Ph.Ds have way too much knowledge floating around up there muddying the waters! I’ll take my score on an internet test if you’ll all keep working on the latest and greatest research!

  18. I got them all right in 4:00. One comment – they need to correct the spelling of one of the words. The correct word is “complementary,” not “complimentary.”

Leave a Reply