Question

In genetic engineering, antibiotics are used for
A) As selectable markers
B) To select the healthy vector
C) As sequence from here replication starts
D) To keep the cultures free of infection
E) Both A and D

Answer 1

Hint: Genetic engineering is additionally called recombinant DNA (deoxyribonucleic acid) technology. Gene-splicing is an element of biotechnology. It’s outlined because the modification in genetic material by man in vitro.

Complete Answer:
In gene-splicing, the specified DNA sequence is cut from the organism into little half and then transferred into the host cell with or without the assistance of vectors.

In rDNA technology main 3 tools are required:
1) Enzymes
2) Vehicles or carrier
3) Passenger DNA
Various types of enzymes are concerned in this technology like lysing enzyme, cleaving enzyme, synthesizing enzyme, joining enzyme and alkaline phosphatase.
DNA acts as the vehicle which transfers the foreign DNA into host DNA.

Mainly 2 types of vehicle is used that is:
(I) Plasmids
(II) Bacteriophage
- Transformation of vector to host is additionally referred to as gene carrier and cloning vector.
- For the cloning vector some necessary gene features are required that is Origin of replication, Selectable marker (Vector have some specific type of gene like antibiotic resistance gene, Gene to formation of toxic material and gene for N2 fixation), and recognition sites.
- Passenger DNA is transferred from one organism to another after cloning with vector DNA.

So, the correct answer is a selectable marker.

Note: Exonucleases, endonucleases, and restriction endonucleases are further 3 varieties of cleaving enzyme.