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.
DNA molecules are carriers of an organism's genetic information. A cell's chromosomes are made from DNA molecules and associated proteins. This chapter looks at the discovery and structure of DNA-the molecule of life.ucleotides are made of one nitrogenous base, one phosphate molecule and one sugar molecule (deoxyribose in DNA and ribose in RNA) There are four different types of nucleotides found in DNA. When drawing the DNA molecule model these nucleotides are referred to by their 'initials': 1  A is for adenine.