Question

Which of the following are used in gene cloning?
A. Plasmids
B. Nucleoids
C. Lomasomes
D. Mesosomes

Answer 1

Hint: Gene cloning refers to the multiplication of the gene. It is done to replicate the desired genes. Gene cloning is done with the help of a vector. A commonly known vector is the extrachromosomal DNA found in bacteria.

Complete answer: Let us look at all the options that are given to us one by one.
-Plasmids: These are the extrachromosomal, non-essential, circular, double-stranded, self-replicating, and autonomous pieces of the DNA in the cells of the bacteria. This extra DNA usually has the properties of antibiotic resistance and virulence due to which they are commonly used as vectors in molecular technology.
-Nucleoids: Nucleoid is the circular DNA found in the bacteria. Nucleoids consist of the vital genes of the organisms. These genes mix with non-histone proteins like polyamines. Nucleoids are not used as vectors as they cannot be transferred from one cell to another.
-Lomasomes: Lomasomes are the outward folds in the plasma membrane of the fungi and some spore-producing plants like algae etc. Lomasomes contain digestive enzymes and they digest the extra cell waste that is produced by the vacuoles.
-Mesosomes: Mesosomes are the inward folds in the cell membrane of the bacteria. Mesosomes are a substitute for the mitochondria. They contain respiratory enzymes. Mesosomes are not used as vectors because they contain no genetic part.
Thus, based on the above information we can conclude that Plasmids are used in gene cloning.
Hence, the correct answer is option (A).

Note: Vectors are the vehicles or the carriers that help in delivering a foreign piece of DNA from one organism to the host organism. They are engineered in such a way that they help in the easy linking of foreign DNA. Vectors also help in the selection of the recombinants from the non-recombinants.