(b) Restriction enzymesare  called “molecular scissors” or chemical scalpels. Restriction enzymes, synthesized by micro-organisms as a defence mechanism which can cleave double-stranded DNA at specific sites called recognition sequences. The recognition sequence is a palindrome, where the sequence of base pairs reads the same on both the DNA strands, when the orientation of reading is kept the same.

(c) Chitinase. are hydrolytic enzymes used  to degrade chitin . It is used to break the cell open to release DNA along with other macromolecules such as RNA, proteins, polysaccharides and also lipids.