Which of the following enzymes is used to join $DNA$ fragments?

What is the function of restriction endonucleases?

$A$ set of genes or $cDNA$ is immobilized on a glass slide and used in transcriptome studies is called:

The first restriction endonuclease type $II$,$...A..$,was isolated by Smith,Wilcox and Kelley from $...B...$ bacterium. It was found to cut $DNA$ molecules at a particular point by recognizing a specific sequence of six base pairs,known as the $...C....$. Here $A, B$ and $C$ can be:

In the gene gun method used to introduce alien $DNA$ into host cells,microparticles of which metal are used?

Which one of the following causes crown gall disease?