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nbme 3 q

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ladybug
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04/28/06 - 08:34 PM

DNA from E. coli and H. influenza is digested with the restrication endonuclease EcoRI and the fragments separated by gel electrophoresis. An examination of teh gel shows that the DNA from H influe was cl;eaved into smaller numerous fragments while E coli was not. Which of the ff best explains tehd ifference?

a. Methylation of ecoli

b. Methylation of h influenza

c. Presence of Introns of ecoli

d . presence of introns of h influenza

e. presence of transposons of ecoli

f. presence of transposons of h influenza

Please exlain. thanks

robin082006
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04/28/06 - 08:46 PM

D

No idea, just guess, didd't here about this

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r_albayunen
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04/28/06 - 10:41 PM

d?
endonuclease digesting the introns ..
a? shaking head

disha
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04/29/06 - 05:52 AM

IS IT B?

ENDONUCLEASE REMOVES DAMAGED BASE PAIRS.

INTRONS ARE SPLICED OUT OF mRNA TRANSCRIPTS.PLZ CORRECT ME IF IM WRONG.

ts97
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05/08/06 - 09:21 AM

I think A:
e.coli methylates bases to protect dna from it's own endonucleases (ECoRI).

Andrew000
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05/15/06 - 06:13 AM

A.........

Andrew000
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05/15/06 - 06:15 AM

ts97 from where do you get this conception can you help us with the reference?

ts97
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05/15/06 - 08:21 AM

from Kaplan lecture's notes for Microbiology

ts97
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05/16/06 - 09:46 AM

My mistake: from Biochemistry lecture

Andrew000
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05/22/06 - 03:17 AM

#10

ts97 which chapter & page thx.

mou
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06/10/06 - 06:16 PM

#11

ans is A as methylation is the only way to prevent break down of any dna

waqastariq

06/12/06 - 01:21 PM

#12

yups

waqastariq

06/12/06 - 01:22 PM

#13

thats correct its D

waqastariq

06/12/06 - 01:23 PM

#14

thats correct its D...
methylation saves from the action of endonuclease...the endonuclease needs a site to attach on the DNA strand while it cant get attached if methylation occurs...

doc179
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10/23/06 - 08:58 AM

#15

I thought its A,
choice D says because introns are present in H.influenza, but then restriction endonuclease can cleave whereever even inside a gene if it finds its palindrome there, right?

girl^interrupted
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11/19/06 - 01:37 PM

#16

A.... Written in Microbial Genetics..Kaplan

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lq2006
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04/28/07 - 03:51 PM

#17

virgola82
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05/02/07 - 07:12 AM

#18

EcoRI comes from E.Coli which prevents his own DNA to be digested by methylating it

So A

sidchicks
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05/02/07 - 12:56 PM

#19

a cant be anything else its straight from kaplan biochem and micro notes

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