Question

Duplicates can arise via several mechanisms.

c. A third mechanism is slippage during DNA replication. Why are such copies less likely to be functional? (2)

Answer 1

Slippage during DNA duplication is,the template shift with respect to the new complementary strand.Sometimes one region of template strand is either not copied or may be copied twice.Therefore this region of DNA is deleted or duplicated twice.

Slippage is the mechanism which creates benign polymorphic variation in short tandem repeats (STRs) . STRs are often referred to as microsatellites.Microsatellites in non-coding regions that do not have any specific function.That is why it is said to be less functional.But this allows them to accumulate mutations unhindered over the generations and gives rise to variability that can be used for DNA fingerprinting and identification purposes.Most of the microsatellites are located in non-coding DNA and are biologically silent.