Question

Production of a human protein in bacteria by genetic engineering is possible because

• A. Bacterial cell can carry out the RNA splicing reactions.
• B. The mechanism of gene regulation is identical in humans and bacteria.
• C. The human chromosome can replicate in bacterial cell.
• D. The genetic code is universal.

Answer 1

Answer: (D)

The genetic code is universal.

Bacterial cells lack the machinery needed for processing of primary transcript; which makes option A wrong. Eukaryotic DNA replication requires specific origin of replications, enzymes and other regulatory machinery which are absent in prokaryotes and hence, they can not replicate a eukaryotic DNA; option C is incorrect.

Prokaryotic genes are polycistronic; the genes for related enzymes are present in cluster which is under regulation of same promoter. Euakryotic genes are monocistronic; each has its own promoter gene which means that gene regulation is not same in both; option B is incorrect. As we know that nucleotide sequence of mRNA is translated into amino acid sequence of protein. A set of three nucleotides serve as a codon that specify an amino acid. Genetic code is universal which means that a particular codon specify a particular amino acid in all the organisms. The mRNA codon "ACU" codes for threonine, irrespective of its source. This enables bacteria to produce a human protein. Correct answer is D.