I f you need to know the exact times that the markets open and close, you have to take time zones into consideration. It is very simple when expressed in GMT. This is Greenwich Mean Time. This is the standard (winter) time in Greenwich, London which is the point of zero longitude on the globe. The normal Forex market hours are 22.00 Sunday GMT to 22.00 Friday GMT.
Genes are made of a chemical called DNA, which is short for 'deoxyribonucleic acid'. The DNA molecule is a double helix: that is, two long, thin strands twisted around each other like a spiral staircase.The DNA double helix showing base pairs. The sides are sugar and phosphate molecules. The rungs are pairs of chemicals called 'nitrogenous bases', or 'bases' for short.There are four types of base: adenine (A), thymine (T), guanine (G) and cytosine (C). These bases link in a very specific way: A always pairs with T, and C always pairs with G. The DNA molecule has two important properties.he rungs are pairs of chemicals called 'nitrogenous bases', or 'bases' for short. There are four types of base: adenine (A), thymine (T), guanine (G) and cytosine (C). These bases link in a very specific way: A always pairs with T, and C always pairs with G. The DNA molecule has two important properties.
Concept 19 The DNA molecule is shaped like a twisted ladder. Earlier work had shown that DNA is composed of building blocks called nucleotides consisting of a deoxyribose sugar, a phosphate group, and one of four nitrogen bases â adenine (A), thymine (T), guanine (G), and cytosine (C).Phosphates and sugars of adjacent nucleotides link to form a long polymer.Other key experiments showed that the ratios of A-to-T and G-to-C are constant in all living things. X-ray crystallography provided the final clue that the DNA molecule is a double helix, shaped like a twisted ladder.n 1953, the race to determine how these pieces fit together in a three-dimensional structure was won by James Watson and Francis Crick at the Cavendish Laboratory in Cambridge, England. They showed that alternating deoxyribose and phosphate molecules form the twisted uprights of the DNA ladder.