How many of the following are incorrect? 

a) Incubating purified DNA molecules with DNA ligase will perform enzyme digestion. 

b) E.coli donot have ‘rop’ gene sequence in their plasmids. 

c) Each restriction endonuclease has specificity in recognising a specific palindromic sequence. 

d) Sexual reproduction do not permit variations.

Except c all are incorrect

Incubating purified DNA molecules with DNA ligase will not perform enzyme digestion. Digestion is by restriction endonuclease

E.coli does have ‘rop’ gene sequence in its plasmids. 

Each restriction endonuclease has specificity in recognising a specific palindromic sequence. 

Sexual reproduction brings about variations in the offspring.