Which antibiotic resistance genes are present in $pBR322$?

There is a restriction endonuclease called $Eco RI$. What does "co" part in it stand for?

$I.$ $Ori$ also controls the copy number of the linked $DNA$.
$II.$ If a foreign $DNA$ ligates at the $BamHI$ site of the tetracycline resistance gene in the vector $pBR322$,the recombinant plasmid loses the tetracycline resistance due to the insertion of foreign $DNA$.
Choose the correct option regarding the above statements.

Which enzyme removes nucleotides from the ends of $DNA$?

Which of the following is used in genetic engineering?

What does the sample of the given base sequence represent?
$5'-GAATTC-3'$
$3'-CTTAAG-5'$