The same restriction endonuclease is used to cleave plasmid. Matching sticky ends should find each other in the test tube. Ligase seals sticky ends. What you have now is a recombinant of human and bacterial genes spliced together. Plasmid is taken up by bacteria.
Plasmids replicate in the bacteria.
Screening for clones that are antibiotic resistant. It means that these clones carry the human gene. By using reverse transcriptase. This is the exception to the Central Dogma of Biology which states that the gene product or protein is translated from the message on the RNA, which was copied from the DNA or gene. DNA copied from RNA is the reverse of what you've learned so far, thus the name reverse transcriptase.