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 bases on one strand pair with the bases on another strand: adenine pairs with thymine, and guanine pairs with cytosine. DNA molecules are long â so long, in fact, that they can't fit into cells without the right packaging. To fit inside cells, DNA is coiled tightly to form structures we call chromosomes.Each chromosome contains a single DNA molecule. Humans have 23 pairs of chromosomes, which are found inside the cell's nucleus.NA sequencing is technology that allows researchers to determine the order of bases in a DNA sequence. The technology can be used to determine the order of bases in genes, chromosomes, or an entire genome. In 2000, researchers completed the first full sequence of the human genome.