Answer:
For many centuries, smallpox devastated mankind. In modern times we do not have to worry about it thanks to the remarkable work of Edward Jenner and later developments from his endeavors. With the rapid pace of vaccine development in recent decades, the historic origins of immunization are often forgotten. Unfortunately, since the attack on the World Trade Center on September 11, 2001, the threat of biological warfare and bioterrorism has reemerged. Smallpox has been identified as a possible agent of bioterrorism (1). It seems prudent to review the history of a disease known to few people in the 21st century.
Edward Jenner is well known around the world for his innovative contribution to immunization and the ultimate eradication of smallpox (2). Jenner's work is widely regarded as the foundation of immunology—despite the fact that he was neither the first to suggest that infection with cowpox conferred specific immunity to smallpox nor the first to attempt cowpox inoculation for this purpose.
Explanation:
To bring oxygen in the body because it is a respiratory organ fish
The cane toad was a failure as a biological control method in Australia because:
-The greyback beetle it was supposed to be eating fed at the top of the sugarcane stalks (which were 6-8 meters in height). Cane toads cannot fly or climb and therefore couldnt feed on the beetles.
-The beetles were out during the daytime, and cane toads feed at night.
-The two species are not seasonally compatible (aren't in the same place at the same time of year).
-The toads needed moist conditions to survive, and so moved away from where they were supposed to be.
-The cane toad eats many native species and often out-competes native species for food and breeding sites, leading to the decline of natives.
-Breeding habits made the cane toads a very invasive species.
