Plasmids are small circular dna molecules found in bacteria that replicate separately from chromosomes. why are plasmids essential for recombinant dna technology? plasmids are able to rapidly reproduce exact copies of cells, so they provide a means to acquire a large number of cells that contain a particular gene of interest. dna from a gene of interest can be inserted into a plasmid, then the modified plasmid can be inserted into a bacterial cell to replicate a gene of interest many times. plasmids can cleave the sugar–phosphate bonds in dna molecules in a staggered manner, creating single‑stranded, "sticky" ends of dna where the gene of interest can attach. plasmids provide the catalytic action required to denature a molecule of dna from a gene of interest that can be used in recombinant dna technology.

DNA from a gene of interest can be inserted into a plasmid, then the modified plasmid can be inserted into a bacterial cell to replicate a gene of interest many times.

Explanation:

Plasmids are the extra-chromosomal circular DNA present in bacterial cells. Plasmids are able to replicate themselves independent of genetic DNA. Their ability to self replicate allows them to maintain themselves in the bacterial cells. This is why plasmids are used as cloning vectors in recombinant DNA technology.

A gene of interest is isolated from the donor cell and is inserted into the plasmid. The recombinant plasmid is introduced into bacterial cells where it replicates the ligated desired gene and allows the gene cloning. For example, the human insulin gene is ligated with plasmid and the recombinant plasmid is introduced in E. coli where it replicates the human insulin gene and allows the production of desired copies of the 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.

explanation:

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.