[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 Watson and Crick Model. After learning that DNA had spiral shape, Watson and Crick determined the structure of DNA. The sugar and phosphate groups are bonded in alternating sequences to form the sides of a twisted ladder. Bases are joined by hydrogen bonds to form the rungs of the ladder.he Watson and Crick Model. After learning that DNA had spiral shape, Watson and Crick determined the structure of DNA. The sugar and phosphate groups are bonded in alternating sequences to form the sides of a twisted ladder. Bases are joined by hydrogen bonds to form the rungs of the ladder.