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tomi fer
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Posts: 40
03/02/04 - 04:35 PM             #1

A bacterial mutant grows normaly at 32 C but at 42 C accumulates short segments of newly synthetized DNA. Whith of the following enzymes is most likely to be defective in this mutant?

a: An endonuclease
B: DNA polymerase
c: An exonuclease
d: Helicase
e: DNA ligase

kiranmayi
Forum Guru

Topics: 237
Posts: 407
03/02/04 - 04:52 PM             #2

is it e: DNA ligase :roll:

asmi
Forum Hero

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Posts: 4,609
03/02/04 - 05:05 PM             #3

A..excision endonuclease.Its due to increase in temperature(heat).

If iam wrong plz do explain the answer.
thanks

Colombia
Forum Guru

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03/02/04 - 05:28 PM             #4

DNA ligase

tomi fer
Forum Junior

Topics: 19
Posts: 40
03/02/04 - 05:59 PM             #5

yes the correct one is DNA ligase because short segments of new DNA that accumulate at 42 C are okazaki fragments and the usually are join together by the DNA ligase, whish is probably temperature sensitive in the mutation. in addition if the ligase is not working, okazaki fragment would not be joined in the replication phase.

asmi
Forum Hero

Topics: 1043
Posts: 4,609
03/02/04 - 06:53 PM             #6

thanks smiling face

that was a good Q :idea:







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