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Author Question: Ya-ling was reading a research report on the challenges learners' face when reading diagrams in ... (Read 111 times) |
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
Vaccines prevent between 2.5 and 4 million deaths every year.
To prove that stomach ulcers were caused by bacteria and not by stress, a researcher consumed an entire laboratory beaker full of bacterial culture. After this, he did indeed develop stomach ulcers, and won the Nobel Prize for his discovery.
Interferon was scarce and expensive until 1980, when the interferon gene was inserted into bacteria using recombinant DNA technology, allowing for mass cultivation and purification from bacterial cultures.
As the western states of America were settled, pioneers often had to drink rancid water from ponds and other sources. This often resulted in chronic diarrhea, causing many cases of dehydration and death that could have been avoided if clean water had been available.