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 (uncountable) ( 1 uncountable) Warfare in which opposing sides occupy trenches and repeatedly fire at one another; usually involving high casualty rates over a long period of time. ( 2 uncountable, by extension) Fighting of any sort which offers no hope of ending soon.