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  #1  
Old 06-18-2013
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DNA Complementary Probe Nucleotide Sequence!

Sickle cell anemia is caused by a missense mutation in codon 6 of the
beta-globin gene.
Codon number 5 6 7 8
Normal allele CCT GAG GAG AAG
Mutant allele CCT GTG GAG AAG
A man with sickle cell disease and his phenotypically normal wife request genetic testing because they are concerned about the risk for their unborn child. DNA samples from the man and the woman and from fetal cells obtained by amniocentesis are analyzed using the PCR to amplify exon 1 of the p-glob in gene. Which 12-base nucleotide sequence was most likely used as a specific probe complementary to the coding strand of the sickle cell allele?
(A) CCTCACCTCAGG
(B) CCTGTGGAGAAG
(C) GGACACCTCTTC
(D) CTTCTCCACAGG
(E) CTTCTCCTCAGG
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Old 06-18-2013
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is it by any chance D?
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Old 06-18-2013
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I will also go for D
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Old 06-18-2013
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The answer is D
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Old 06-19-2013
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Anybody plz explain..
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Old 06-21-2013
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Sickle cell anemia is caused by a missense mutation in codon 6 of the
beta-globin gene.
Codon number 5 6 7 8
Normal allele CCT GAG GAG AAG
Mutant allele CCT GTG GAG AAG
DNA samples from the man and the woman and from fetal cells,Which 12-base nucleotide sequence was most likely used as a specific probe complementary to the coding strand of the sickle cell allele?

(B) CCTGTGGAGAAG

(D) CTTCTCCACAGG


if at the top coding strand of sickle cel alele is given
Mutant allele is: 5'.....CCT GTG GAG AAG....3'
d) is the corect answr ok

how??
read it from 3' end and put the nucleotide sequnce acording to that,
--------5'..CCT GTG GAG AAG....3'
option D:--CTT CTC CAC AGG

Option B: (GGACACCTCTTC this is the corect sequence but read it from LAST (3' end) to the first (5' end) alphabet which matches the option D thats why D Is the corect).

shoty now pls post the answr
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Last edited by neha_subh; 06-21-2013 at 02:04 AM.
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Old 06-21-2013
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Default Sory i did one mistake..

Sickle cell anemia is caused by a missense mutation in codon 6 of the
beta-globin gene.
Codon number 5 6 7 8
Normal allele CCT GAG GAG AAG
Mutant allele CCT GTG GAG AAG
DNA samples from the man and the woman and from fetal cells,Which 12-base nucleotide sequence was most likely used as a specific probe complementary to the coding strand of the sickle cell allele?

(C) GGACACCTCTTC

(D) CTTCTCCACAGG


if at the top coding strand of sickle cel alele is given,then put the nucleotide sequnce from 3' to 5' end
Mutant allele is: 5'.....CCT GTG GAG AAG....3'
----------------3'.....GGA CAC CTC TTC...5' (botom line)
now read the botom line from 5' to 3' end



Option C: (GGACACCTCTTC this is the corect sequence but read it from LAST (5' end) to the first (3' end) alphabet which matches the option D thats why D Is the corect).

shoty now pls post the answr
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Last edited by neha_subh; 06-21-2013 at 03:48 AM.
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