Double-stranded DNA consists of two polynucleotide chains whose nitrogenous bases are connected by hydrogen bonds. Within this arrangement, each strand mirrors the other as a result of the anti-parallel orientation of the sugar-phosphate backbones, as well as the complementary nature of the A-T and C-G base pairing.
The Egg Nebula (also known as RAFGL 2688 and CRL 2688) is a bipolar protoplanetary nebula approximately 3,000 light-years away from Earth. Its peculiar properties were first described in 1975 using data from the 11 µm survey obtained with sounding rocket by Air Force Geophysical Laboratory (AFGL) in 1971 to 1974. (Previously, the object was catalogued by Fritz Zwicky as a pair of galaxies.) http://en.wikipedia.org/wiki/Egg_Nebula
This DNA is a teaching model; It demonstrates different structural units of DNA: Phosphorus, Oxygen, Deoxyribose, CH2 group, 4 types of nitrogenous bases and bonding molecules of hydrogen. Each unit is shape and color coded.
DNA Discovery and Structure - Genetics PowerPoint and Handouts. Engage students with a fun coloring lesson on the history of DNA's discovery, its nitrogen base structure, and its function in the cell's nucleus. Follow it up with our version of a DNA extraction lab!