Question

In genetic engineering, the antibiotics are used
A. To select healthy vectors
B. As sequence from where replication starts
C. To keep the cultures free of infection
D. As selectable markers

Answer 1

Hint: Antibiotics are the medications which are antimicrobial substances that are applied to living tissue or living skin to reduce the possibility of infection, putrefaction or sepsis. Antibiotics help in safely destroying bacteria within the body and from the disinfectants which are used to destroy microorganisms found on non-living substances.

Complete answer:
Genetic engineering is used to do genetic modifications to manipulate an organism's genes using biotechnology. Genetic engineering is essential to change the makeup of cells, including the transfer of the genes within the species boundaries to produce improved or novel organisms. In genetic engineering a construct is usually created and used to insert this modified DNA into the host organisms.
Vector organisms carry an antibiotic-resistant gene which helps to choose the recombinant cells from non-recombinant cells as only the recombinant cells would exhibit the antibiotic resistance and are able to survive on an antibiotic rich medium. These types of genes that the host cell requires for growth under certain conditions and helps in differentiation of recombinant cells from non-recombinant cells are called selectable markers. The first recombinant DNA molecule was made by Paul Berg in 1972.

Hence, the correct option is D. As selectable markers.

Note: Genetic engineering is used to raise commercialized genetically modified crops which help in providing economic benefit to farmers in many different countries. This technique is also used to produce vaccines, hormones, and other drugs which are helpful to cure genetic disease through gene therapy.