Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    Hi i really need help on a hardy weinberg question, jan 2011 question 2c, 16% of the population of europe are rhesus negative(rr) and i must find out the population of the rhesus positice(Rr). The mark scheme hasnt helped much at all, id be grateful for any help guys! Xo
    Offline

    3
    ReputationRep:
    (Original post by Jessyd)
    Hi i really need help on a hardy weinberg question, jan 2011 question 2c, 16% of the population of europe are rhesus negative(rr) and i must find out the population of the rhesus positice(Rr). The mark scheme hasnt helped much at all, id be grateful for any help guys! Xo
    rr indicates homozygous recessive.

    If you remember the HW equation, this is calculated by q2

    Therefore, q2 = 16% = 0.16

    You can now solve for q.

    We want Rr which indicates heterozygous.
    If you remember the HW equation, this is calculated by 2pq.

    We have q, but we need p.
    This uses the other HW equation: p + q = 1.

    Rearranging it shows that p = 1 - q
    And now we can solve for p.

    Now that we have p and q, we can finally calculate 2pq.
    Spoiler:
    Show
    Solve q = 0.4
    ∴ Solve p = 0.6
    ∴ Solve, Rr 2pq = 2 × 0.4 × 0.6 = 0.48
    • Thread Starter
    Offline

    0
    ReputationRep:
    Thank you! I actually understand it now
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Has a teacher ever helped you cheat?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Write a reply...
    Reply
    Hide
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.