Animals, plants, and bacteria are examples of living systems that share many properties distinguishing them from nonliving things. These properties are branched into theories.
Cellular organization Fundamental unit of life is the cell – all living things are made up of cells. Metabolism Living things take up energy-rich materials and give out waste to environment. Some energy fuels life processes some accumulates and is released after death. Selective response Living things respond selectively to stimulation in the environment. Organisms recognize certain chemicals as nutrients while ignoring others.
Scientific theories Homeostasis Living systems have some capacity to change harmful conditions into conditions more favorable to their continuing existence – the conversion of chemical compounds. Growth and biosynthesis Living systems go through phases during which they make more of their own material. Genetic material Living systems contain genetic material (DNA and RNA) to allow inherited traits. Reproduction Living systems can reproduce & pass on genetic material. Population structure Organism form populations. Of these organism capable of sexual processes, a population is all those organisms that can interbreed with one another.
Classic germ theory: pathogenicity as a characteristic of pathogen only
NEW PARADIGM Darwinism (since 1859) Classical Mendelian genetics (since 1865 or 1900) Germ theory of disease (Pasteur, Koch, since 1880) Modern evolutionary theory (since 1940) Molecular genetics (since 1950s) Sociobiology (since 1975) Mind–body connections (since 1980s) Pathogenicity as an interaction of pathogen and host (since 1990s)
It is regarded as the worst accident in the history of nuclear power.
A plume of radioactive fallout drifted over parts of the western Soviet Union, Eastern and Western Europe, Scandinavia, the British Isles, and eastern North America. Large areas of Ukraine, Belarus, and Russia were badly contaminated
Resulted in the evacuation and resettlement of over 336,000 people. About 60% of the radioactive fallout landed in Belarus, according to official post-Soviet data
1932 The Tuskegee Syphilis Study begins. 200 African-American men infected with syphilis are never told of their illness, are denied treatment, and instead are used as human guinea pigs in order to follow the progression and symptoms of the disease. They all subsequently die from syphilis, their families never told that they could have been treated.