Biotechnology

Answer (d) Arabidopsis

Endonucleases are enzymes that cleave the phosphodiester bond within a polynucleotide chain. Some, such as deoxyribonuclease-I, cut DNA relatively non-specifically (without regard to sequence), while many, typically called restriction endonuclease or restriction enzyme, cleave only at very specific nucleotide sequences.

Answer (b) EcoR l

In addition to the single large circular chromosome, each bacterial cell contains from 1 to 20 much smaller circular duplex DNA molecules which are called as plasmids. Plasmids replicate along with the bacterial chromosome. Their function varies. Some of them become incorporated into the host cell chromosome and are called episomes. These are sometimes transferred from one bacterial cell to another during conjugation.

The single-stranded free ends that project from each fragment of DNA duplex are unpaired bases and are known as "sticky ends". Sticky ends can join with similar complementary ends of DNA fragment from some other sources.