Final answer:
Biologists have identified over 800 restriction endonucleases with unique specificities. These enzymes recognize and cleave DNA at specific sequences, creating unique DNA fingerprints. They are categorized into three types and named after the bacterial species they are derived from.
Step-by-step explanation:
Biologists have identified that there are more than 800 restriction endonucleases discovered so far, each with its own specificity.
These enzymes recognize and cleave DNA at specific nucleotide sequences, creating a unique DNA fingerprint for each individual.
Restriction endonucleases are categorized into three types (type-I, II, and III) and are named after the three-letter abbreviation of the bacterial species they are derived from.
For example, Eco RI is a type-II restriction endonuclease derived from the bacterium Escherichia coli.