Epigenetics is the study of how proteins and other molecules that bind to DNA and chromosomes can change gene expression without changing the DNA sequence.

Digital PCR (dPCR) is a computational tool used to calculate theoretical polymerase chain reaction methods that can be used to directly quantify and clonally amplify nucleic acids including DNA, cDNA or RNA.

A variable number tandem repeat (VNTR) is a location in a genome where a short nucleotide sequence is organised as a tandem repeat.

Random amplified polymorphic DNA (RAPD) is a method that reveals intra-specific variation and diversity between species.

Gene pool is associated with robust populations that can survive bouts of intense selection. Meanwhile, low genetic diversity (see inbreeding and population bottlenecks) can cause reduced biological fitness and an increased chance of extinction, although as explained by genetic drift, new genetic variants, which may cause an increase in the fitness of organisms, are more likely to fix in the population if it is rather small.

A genomic library is a collection of cloned DNA pieces from a genome.

The phi X 174 bacteriophage was the first DNA-based genome to be sequenced. This work was completed by Fred Sanger and his team in 1977.

This option is correct because the term ‘genome’ was given by Hans Winkler, professor of botany at the University of Hamburg, Germany.

Biolistics is a technique of using very small metal particles coated with desired gene in the gene transfer.

This option is correct because G. J. Mendel is the father of genetics and the father of human genetics is Archibald Garrod.

This option is correct because in eukaryotes, there is a set of positively charged, basic proteins called histones. Histones are rich in the basic amino acid residues, lysines and arginines, and in a typical nucleus, some region of chromatin is loosely packed (and stains light) and is referred to as euchromatin. The chromatin that is more densely packed and stains dark is called as heterochromatin.

This option is correct because all are correctly matched. RNA polymerase I transcribes rRNAs (28S, 18S and 5.8S). RNA polymerase II transcribes precursor of mRNA, the heterogeneous nuclear RNA (hnRNA). RNA polymerase III is responsible for transcription of tRNA, 5srRNA and snRNAs (small nuclear RNAs).

This option is correct because explant is any portion taken from a plant that will be used to initiate a culture; probe is a fragment of DNA or RNA, which is used for hybridization; restriction endonucleases are molecular scissors that recognise short DNA sequences, usually 4–8 bp in length and cut the phosphodiester bond within or close to their target sites to generate a double-stranded break; and ligases are called 'molecular stitchers' because of their ability to catalyse the joining of two large molecules by forming a new chemical bond.

This option is correct because the normal role of restriction endonucleases in bacterial cells is to degrade invading phage DNA. Bacterial cells protect their own DNA from degradation by restriction endonucleases by methylating the DNA at the sites that the enzyme recognises.  

This option is correct because in capping, methyl guanosine triphosphate is added to the 5'-end of hnRNA. In tailing, adenylate residues are added at 3'-end in a template independent manner. It is the fully processed hnRNA, now called mRNA, that is transported out of the nucleus for translation.