Mutations in these genes result in abnormal or failed development of polarization in the Drosophila embryo. Nusslein-Volhard's experiments in 1979 identified and characterized all mutant alleles that affected the dorsal-ventral axis. Genes affecting dorsal-ventral polarization fall into two categories:
Biological warfare (BW)âalso known as germ warfare âis the use of biological toxins or infectious agents such as bacteria, viruses, and fungi with the intent to kill or incapacitate humans, animals or plants as an act of war.
Trench Warfare. Trench warfare is a type of fighting where both sides build deep trenches as a defense against the enemy. These trenches can stretch for many miles and make it nearly impossible for one side to advance. During World War I, the western front in France was fought using trench warfare.