1 Chronic bronchitis: A form of COPD characterized by a chronic productive cough. 2  Emphysema: Lung damage allows air to be trapped in the lungs in this form of COPD. 3  Difficulty blowing air out is its hallmark. 4  Acute bronchitis: A sudden infection of the airways, usually by a virus.
There are only 46 DNA molecules ( 23 pairs) in human somatic cell. There are about 22000 genes and close to 3.2 billion base pairs in total.
The DNA of a virus may be as small as a few thousand base pairs. However, the DNA of E. coli, a bacterium has 4 million base pairs and the human genome contains 6 billion base pairs. In general, the more complex the organism, the greater the DNA content in its cells.