1. Dismiss Notice
  2. Guest, be sure to check out How To Get Into Dental School, our free downloadable PDF with step-by-step details for dental school applicants!
    Dismiss Notice
  3. Dismiss Notice
  4. Download free Tapatalk for iPhone or Tapatalk for Android for your phone and follow the SDN forums with push notifications.
    Dismiss Notice

Destroyer #228 - Help?

Discussion in 'DAT Discussions' started by STACM, Jun 21, 2008.

  1. STACM

    7+ Year Member

    Joined:
    Dec 24, 2006
    Messages:
    315
    Likes Received:
    0
    In BIO question #228 of destroyer it says "if a male and female are both carriers of the gene, what is the probability that they have a diseased child?", but in the answer they take into account a 1/50 (2%) chance each parent carries the gene. So how can this be...in the question is says each parent IS a carrier (100% chance the parent carries the gene), but in the answer they say there is a 2% chance a parent is a carrier.
     
  2. Note: SDN Members do not see this ad.

  3. STACM

    7+ Year Member

    Joined:
    Dec 24, 2006
    Messages:
    315
    Likes Received:
    0
    anyone??
     
  4. Dotoday

    7+ Year Member

    Joined:
    May 27, 2007
    Messages:
    1,559
    Likes Received:
    88
    Let me look at the question a little more. I`ll get back to you. Sounds like some info is missing.
     
  5. STACM

    7+ Year Member

    Joined:
    Dec 24, 2006
    Messages:
    315
    Likes Received:
    0
    cool thanks!
     
  6. Dotoday

    7+ Year Member

    Joined:
    May 27, 2007
    Messages:
    1,559
    Likes Received:
    88
    Hi, sorry to take so long to get back to you, I was not able to get on the internet.
    OK, so thge questions says that the parents are 1/50 people who carry the recessive mutation, but they are only carriers , not homozygous. Therefore 1/50 people puts them at 0.02% of people that carry the mutation. You are right if both parents are carriers then they each have 50% of transmitting that information to their children and a child has 25% chance of inheriting the same mutant allele from both parents. However, you must consider the fact that each parent is 1/50 people who has the allele and therefore each parent has 0.02% chance of carrying the allele in a first place. So, what you do is you take 0.02 *0.02 (from each parent)*0.25 (chance that a child inherits mutant allele from both parents) = 0.01% chance that in withing the population the child has 0.01% chance of being a homozugous mutant. This includes the criteria that the child has both parents which have 0.02% chance each of carrying the mutant allele.
    The answer is right, just the wording may be a bit confusing.
    Hope this helps.
     
  7. krnstylenow

    Joined:
    Jun 28, 2008
    Messages:
    5
    Likes Received:
    0
    i dont understand this question as well.

    when i first did it, i thought oh. 25% chance to be recessive homozygous, then 2% chance to be actualy sick so I thought it was 0.5% but then the answer was not there!!!

    I think it is a really poorly worded question. I for sure thought it said, given the person is homozygous recessive, the probability of actually being sick is 2%.
     
  8. klutzy1987

    klutzy1987 StudyingSucks Letsgo Mets
    5+ Year Member

    Joined:
    Jan 28, 2008
    Messages:
    2,134
    Likes Received:
    3
    Status:
    Dental Student
    The problem is it tells you that both parents are carriers so therfore why should you have to even care bout what the probability of them being carriers is. It tells you straight out that they are carriers. The answer should just be .5%
     
  9. NuckingFutz

    7+ Year Member

    Joined:
    Nov 20, 2006
    Messages:
    140
    Likes Received:
    0
    Status:
    Dental Student
    I was confused about this one too. I think that it may be an error in destroyer :eek:
     
  10. gentile1225

    5+ Year Member

    Joined:
    May 12, 2008
    Messages:
    383
    Likes Received:
    0
    Status:
    Pre-Dental
    i think dotoday got it right. nice job breaking the problem down.
     

Share This Page