Question

Problems in obtaining large amounts of proteins encoded by recombinant genes can often be overcome by using:
A. BACs 
B. Expression vectors
C. YACs
D. All of these

Answer 1

Hint: Recombinant Protein is a protein encoded by a gene. The formation of recombinant protein is performed in specialized vehicles called vectors. Recombinant technology is the process involved in the development of recombinant proteins.

Complete Step-by-step answer:
A bacterial artificial chromosome (BAC) is a DNA construct, based on a functional fertility plasmid (or F-plasmid), used for transforming and cloning in bacteria, usually E. coli.

Yeast artificial chromosome (YAC) is a human-engineered DNA molecule used to clone DNA sequences in yeast cells. YACs are often used in connection with the mapping and sequencing of genomes. Segments of an organism's DNA, up to one million base pairs in length, can be inserted into YACs.

Recombinant proteins are proteins encoded by recombinant DNA that were cloned in an expression vector supporting the expression of the gene and translation of messenger RNA. Modification of the gene by recombinant DNA technology can result in the expression of a mutant protein.

Recombinant protein is a manipulated form of the native protein, which is created in several ways to enhance the production of proteins, modify gene sequences, and manufacture useful business products. Many recombinant proteins need protein modifications, like glycosylation, which are available only in eukaryotic cells. Yeast, mammalian cell, and insect cell culture systems provide such post-translation modifications. 

Therefore the correct answer is Option D.
Note: Recombinant protein production starts at the genetic level, in which a coding sequence for the protein of interest is first isolated and cloned into an expression plasmid vector. Most recombinant proteins for therapeutic purposes are from humans but are expressed in microorganisms like yeast, bacteria, or animal cells in culture.