Question

Restriction endonuclease Hind II always cuts the DNA molecule at a particular point by recognizing a specific sequence of
A) Six base pairs
B) Five base pairs
C) Four base pairs
D) Seven base pairs
E) Three base pairs

Answer 1

Hint: Restriction endonucleases also called restriction enzymes. These cut the DNA molecules at specific sequences and it is produced by a bacteria that cleaves DNA. It cuts the DNA into small fragments in a very precise way and at or near the recognition sites. These are often called molecular scissors.

Complete answer: Restriction endonuclease is a protein delivered by microbes that divides DNA at explicit locales along with the particle. Restriction endonucleases cut the DNA twofold helix in exact manners. It cuts DNA into pieces at or close to specific acknowledgment locales inside the particle known as restriction endonuclease. These chemicals are called restriction proteins since they confine contamination of microbes by certain infections (i.e., bacteriophages), by corrupting the viral DNA without influencing the bacterial DNA. Subsequently, their capacity in the bacterial cell is to devastate unfamiliar DNA that may enter the cell. The restriction enzyme perceives the unfamiliar DNA and cuts it at a few locales along with the particle. Every bacterium has its own interesting restriction chemicals and every compound perceives just one sort of succession. These are further of four types. The double-stranded DNA or RNA molecule is made up of a nucleic acid sequence that is called a palindromic sequence; if read in one direction on the first strand, it complements the sequence on the other strand. Restriction enzymes also recognize the palindromic sequences. These enzymes bind to the DNA in a specific configuration and highlight the chances of both strands of DNA are cut accordingly.
For example- Recognition sequence for Hind II-
\[5' - GTPyPuAC - 3'\]
$3' - CAPuPyTG - 5'$
Hence, the restriction endonuclease Hind II always cuts the DNA molecules at a particular point by recognizing a specific sequence of six base pairs. So, the correct option is (A).

Note: Restriction enzymes have the ability to perceive specific base successions on DNA and afterward to cut each strand at a given spot. Consequently, they are additionally called 'molecular scissors'. The characteristic wellspring of restriction endonuclease is bacterial cells.