[mÌ¥ÉÌÅ]) are an ethnic group from the mountainous regions of China, Vietnam, Laos, and Thailand. Hmong are also one of the sub-groups of the Miao ethnicity (èæ) in southern China. Hmong groups began a gradual southward migration in the 18th century due to political unrest and to find more arable land.
In this way a DNA molecule is similar in structure to a ladder in which the sugar and phosphate groups make the uprights and the nitrogen base groups the rungs. There are four types of nitrogen bases or base groups. 1  Adenine (A). 2  Thyamine (T).3  Cytosine (C). 4  Guanine (G).he nucleotides in the DNA molecule are linked in series from one phosphate, to the next sugar, to the next phosphate and so on. The DNA molecule can be considered as a ladder with the phosphate and the sugar molecules making up the uprights and the bases making up the rungs.
DNA is an example of a macromolecule, i.e. a large molecule with a special shape, which is built up from many smaller parts called sub-units. If you could magnify part of a nucleus, you would see the DNA molecule looking like a twisted rope ladder - a double helix. The two strands forming the sides of the ladder give it a strong yet flexible structure, which does not vary along its length. Stretched between these are the rungs of the ladder, the parts of the DNA molecule which vary, and so the differences carry genetic information. These parts are made up of sections called bases, which fit together in pairs