About Tac Light. Tac Light is a small-but-powerful flashlight by Bell & Howell that has been advertised on television in 2016. The official product website is trytaclight.com, which was registered in April 2016. The screenshot below was taken of the official website in May 2016. 22 times brighter than regular flashlights (600 lumens)
However, only four bases: A (adenine), C (cytosine), G (guanine), and T (thymine) constitute the backbone of the molecule. The DNA molecule is made up of two polynucleotide strands intertwined together to form a long helical structure, the DNA double helix.
Chromosomes are composed of DNA. A gene is a subset of the DNA sequence having an identifiable function. The DNA in between the genes is called junk DNA. Going down the DNA sequence of a chromosome we encounter gene, junk DNA, gene, junk DNA, etc. In between each gene is junk.