Aresearcher is preparing to insert a human gene of interest into a bacterial plasmid in order to clone the human gene. she has genetically engineered the plasmid to carry a gene amp r , which confers resistance to the antibiotic ampicillin. she will include ampicillin in the plating medium when she grows the recombinant bacteria. why has she engineered the plasmid to include an antibiotic resistance gene?

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.