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which of them can be used as vector?

Bacteria is also used as a vector !!???? In genetic engineering, a DNA segment) of interest, is transferred to the host gene cell through a vector. Consider the following four agents (A-D) in this regard and select the correct option about which one or more of these can be used as a vector/vectors Statements : (A) A bacterium (B) plasmid (C) plasmodium (D) bacteriophage (A), (B) and (D) only, (A) only, (D) only or (A) and (C) only
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S safeer


Vector in genetic engineering is usually a DNA segment used as a carrier for transferring selected DNA into living cells. These are as follows:

(1) Plasmid: Plasmid is extra chromosomal, closed circular double stranded molecules of DNA present in most eukaryotes. All plasmid carry replicons pieces of DNA that have the genetic information required to replicate. Plasmid pBR 322 was one of the first widely used cloning vectors, it contain both ampicillin and tetracycline resistance genes.

(2) Phage: It is constructed from the phage l chromosomes and acts as bacteriophage cloning vectors.

(3) Cosmid: The hybrids between plasmid and the phage l chromosome give rise to cosmid vectors.

(4) Beside all these there are artificial chromosomes like

(i) BACs (Bacterial Artificial chromosomes)

(ii) YACs (Yeast Artificial chromosomes)

(iii) MACs (Mammalian Artificial chromosomes) are very efficient vectors for eukaryotic gene transfers