Question

Luciferin is a protein produced by fireflies that gives them their characteristic glow. The gene responsible for the production of the protein luciferin can be expressed by E. coli, a bacterial cell.
Which statement best explains why this is possible?
A) Fireflies and bacteria have the same genes and produce all the same proteins.
B) DNA replication is the same in both fireflies and bacteria.
C) Both fireflies and bacteria have a recent common ancestor.
D) The genetic code is the same in all organisms.
E) Protein synthesis occurs in the exact same way in both fireflies and bacteria.

Answer 1

Hint: Luciferin is a generic term for the compound that undergoes oxidation to produce bioluminescence in certain organisms like fireflies.

Complete answer:
Luciferin is a native compound in fireflies and it can be expressed by the bacteria E. coli by synthetically transforming the bacteria with plasmid encoding the gene responsible for the production of luciferin. On supplementing the bacteria with compounds that promote the translation of the plasmid, luciferin can be expressed in E. coli.

Now, let us look at each option one by one.
>Option A : Fireflies and E. coli are organisms which belong to two very different families of organisms; as a result, the number of chromosomes as well as the number of genes in both these organisms differ from each other. Therefore, this option is incorrect and fails to explain the question.
>Option B: DNA replication is a process that a cell undergoes when it divides into two or more fragments to produce its progeny. This process differs from the process of expression of proteins in a cell or an organism. Therefore, this option is incorrect and does not explain the question.
>Option C: As mentioned for option (A), fireflies and E. coli are organisms which belong to two very different families of organisms; as a result, they cannot have any recent common ancestors. Therefore, this option is incorrect and cannot explain the statement in the question.
>Option D: The genetic code i.e., the set of codons in the DNA encoding particular amino acids for the production of proteins, though mostly similar, are not the same for all organisms. Slight differences can be observed in the genetic code in organisms belonging to different families of the phylogenetic tree. Therefore, this option is incorrect and cannot satisfy the question.
>Option E: Protein synthesis occurs by the translation of the data present in the mRNA generated from the parent DNA strand. This process occurs by the translation of the nucleic acid codons present in the mRNA with the help of ribosomes and tRNA molecules and remains the same in all organisms.Therefore, this is the correct option and best explains the question.

Thus, the statement is (E) is the correct answer i.e, Protein synthesis occurs in the exact same way in both fireflies and bacteria.

Note:The production of luciferin is catalysed by the enzyme luciferase. Apart from fireflies, this bioluminescent compound is also present in certain other organisms including light producing marine and terrestrial microorganisms.