Plasmids used in vitro to done foreign DNA fragments are called A. Transgenic B.
ID: 84696 • Letter: P
Question
Plasmids used in vitro to done foreign DNA fragments are called A. Transgenic B. cDNA C. Clones D. Vectors E. Conjugants What is genetic transformation? A. A cell changing from one form to another B. A cell taking up genetic material from the environment C. A Cell switching from one growth phase to another Plasmid vectors used in cloning often contain a gene for the N-terminal 146 amino acids of the enzyme beta-galactosidase. What is the purpose of including this gene in the vector? A. It allows selection of E. coli host cells that contain the plasmid. B. It allows selection of E. coli host cells that contain plasmid in which the insert has been ligated. C. It cleaves the insert to allow it to be ligated into the vector. D. It enables the plasmid vector to replicate in E. coli host cells. Good cloning vectors must possess all but which of the following qualities? A. they should possess their own origin of replication B. They should be readily accepted by the cExplanation / Answer
Q1. Vector.
Plasmids are naturally occuring circular, extrachromosomal, autonoumously replicating DNA, present in many prokaryotes and some yeasts.Plasmid vectors provide a simple way of coning simple DNA fragments in bacterial cells.
Q2: A cell taking up genetic material from the environment.
Q3: It allows selection of E.coli cells that contain plasmids in which the insert has been ligated.
B-galactosidase activity can be used as an indicator of whether the insert is there or not.This is acheived by blue white screening.If the gene is not ligated, galactosidase gene will be functional and will produce blue colour on x-gal while if gene is interupted by the DNA insert galactosidase will not be functional and hence colonies will appear white.
Q4; They should be resistant to restriction endonucleases.
Vectors shpould have restriction sites to allow themselves to be cut and inserted with a DNA fragment.