The hallmark of the double stranded helical structure of DNA is the hydrogen bonding between the bases from opposite strands. During transcription also, one of the strands of DNA acts a template to direct the synthesis of complementary RNA.
In bacteria, the transcribed mRNA is functional, and hence can directly be translated. In eukaryotes, the gene is split.
Human genome project was a mega project that aimed to sequence every base in human genome. This project has yielded much new information. Many new areas and avenues have opened up as a consequence of the project.
DNA Fingerprinting is a technique to find out variations in individuals of a population at DNA level. It works on the principle of polymorphism in DNA sequences. It has immense applications in the field of forensic science, genetic biodiversity and evolutionary biology.