Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 10 Answered

How does DNA error takes place?
Asked by vidyatmika | 03 Feb, 2010, 11:23: AM
answered-by-expert Expert Answer

While most DNA replicates with fairly high fidelity, mistakes do happen, with polymerase enzymes sometimes inserting the wrong nucleotide or too many or too few nucleotides into a sequence. Fortunately, most of these mistakes are fixed through various DNA repair processes. But some replication errors make it past these mechanisms, thus becoming permanent mutations. These altered nucleotide sequences can then be passed down from one cellular generation to the next, and if they occur in cells that give rise to gametes, they can even be transmitted to subsequent organismal generations. Moreover, when the genes for the DNA repair enzymes themselves become mutated, mistakes begin accumulating at a much higher rate.

It is suspected that most DNA replication errors are caused by mispairings: either between different but nontautomeric chemical forms of bases or between "normal" bases that nonetheless bond inappropriately because of a slight shift in position of the nucleotides in space. This type of mispairing is known as wobble. It occurs because the DNA double helix is flexible and able to accommodate slightly misshaped pairings.

 

Replication errors can also involve insertions or deletions of nucleotide bases that occur during a process called strand slippage. Sometimes, a newly synthesized strand loops out a bit, resulting in the addition of an extra nucleotide base. Other times, the template strand loops out a bit, resulting in the omission, or deletion, of a nucleotide base in the newly synthesized, or primer, strand. Regions of DNA containing many copies of small repeated sequences are particularly prone to this type of error. Also a mutation could occur that produces repeats of some of the bases.

Answered by | 09 Feb, 2010, 08:36: AM
CBSE 10 - Biology
1+1
question image
Asked by sathishkumar.sk6680 | 26 Jan, 2024, 09:35: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Biology
Asked by vramesh.kumar1804 | 09 Jan, 2024, 10:34: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Biology
Asked by navinkumar785790 | 17 Jun, 2023, 10:33: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Biology
Asked by paresh0311 | 20 Mar, 2023, 02:52: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Biology
Asked by nitusinghparihar309 | 26 Dec, 2022, 09:32: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Biology
Asked by blessybhatia09 | 17 Apr, 2022, 10:47: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Biology
Asked by srestasingh7 | 26 Dec, 2021, 10:36: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Biology
Asked by aaazwasi | 25 Jun, 2021, 12:23: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
Get Latest Study Material for Academic year 24-25 Click here
×