http://www.physorg.com/ en-us Physorg.com internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. (PhysOrg.com) -- Meiosis - the pairing and recombination of chromosomes, followed by segregation of half to each egg or sperm cell - is a major crossroads in all organisms reproducing sexually. Yet, how the cell precisely choreographs these chromosomal interactions is a long-standing question. http://www.physorg.com/news177322387.html Biology Fri, 13 Nov 2009 08:13:35 EST news177322387 When it comes to the two basic types of cells, prokaryotes and eukaryotes, compartmentalization is everything. Prokaryotes are evolutionarily ancient cells that only have a membrane surrounding their outer boundary, while the more complex eukaryotes have an outer membrane and membrane bound compartments within the cell. Perhaps most notable is the double layered membrane that surrounds the nucleus, the cellular compartment which houses the cell's genetic material. http://www.physorg.com/news174050458.html Chemistry Tue, 06 Oct 2009 12:25:25 EST news174050458 (PhysOrg.com) -- To protect their DNA, cells in higher organisms are very choosy about what they allow in and out of their nuclei, where the genes reside. Guarding access is the job of transport machines called nuclear pore complexes, which stud the nuclear membrane. Despite these gatekeepers` conspicuously large size (they are made of 30 different proteins), they have proved largely inscrutable to researchers over the years. But bit by bit, scientists are learning how these machines work. http://www.physorg.com/news169828329.html Biology Tue, 18 Aug 2009 16:20:01 EST news169828329 (PhysOrg.com) -- A cell's nucleus - home of it its most precious contents - is a delicate envelope that, without support, is barely able to withstand the forces that keep it in place. Now, researchers have discovered a network of molecules in the nuclear membrane that provide the nucleus with rigidity and also facilitate a previously undiscovered form of communication between the cell`s nucleus and its cytoplasm. http://www.physorg.com/news137420024.html Biology Fri, 08 Aug 2008 13:13:44 EST news137420024