[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.
  The twisted ladder metaphorA DNA molecule is often likened to a spiral (or twisted) ladder. In this analogy, the rungs of the ladder are the base pairs (A-T and G-C). The sides of the ladder are the sugar-phosphate backbones of the two strands. This refers to B form DNA.wo hydrogen bonds form between adenine and thymine; three hydrogen bonds form between guanine and cytosine. There are three forms of DNA that differ significantly. The most common, B form, is the structure most people have heard of.