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.
Before the 20th century, biological warfare took on three main forms: (1) deliberate poisoning of food and water with infectious material, (2) use of microorganisms or toxins in some form of weapon system, and (3) use of biologically inoculated fabrics. Attempts to use biological weapons date back to antiquity.