genetics - Biology Forum

last updated by

wbla3335 18 years, 2 months ago

4 voices

5 replies

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- September 6, 2006 at 2:47 am #5646
  Cris
  Participant
  hi everybdy,
  i have a ?, how many different DNA molecules 8 nucleotide pairs long are possible???
  please help me
- September 6, 2006 at 3:34 am #54382
  mith
  Participant
  try writing them out and see if there’s a pattern
- September 6, 2006 at 3:43 am #54383
  Cris
  Participant
  Thanks for helping me, but could you be a bit more specific, i still don’t understand how am i suppose to find the answer…
- September 6, 2006 at 6:53 am #54391
  wbla3335
  Participant
  4X4X4X4X4X4X4X4=65536 for a single strand, as in a primer. Twice this number if you include the complementary antisense strand (each strand being a different molecule), but I suppose some of the complementary strands would be the same as some of the sense strands, so the actual number of different molecules would be less than 131,072. Anyone care to tackle this issue?
- September 7, 2006 at 2:00 am #54434
  canalon
  Participant
  Multiplying by 2 does not make sense, since the antisense molecule is constrained by the sense one, there is only 4 choice for each pair so 4^8 is the answer.
- September 7, 2006 at 6:40 am #54444
  wbla3335
  Participant
  Hi Canalon,
  Yes, I see your point. ALL antisense strands will have an identical sense counterpart. This certainly makes things easier. So, 65536 it is.
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