|
|
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.
Blood is approximately twice as thick as water because of the cells and other components found in it.
HIV testing reach is still limited. An estimated 40% of people with HIV (more than 14 million) remain undiagnosed and do not know their infection status.
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.
![Flower part number is a characteristic difference between monocots and eudicots (a) Flowers and buds](https://biology-forums.com/gallery/47/medium_33_23_07_11_1_52_40.jpeg)
![In 1891 William Dean Howells championed the poetry of Emily Dickinson: “This poetry is as characteri](https://biology-forums.com/gallery/47/medium_376716_26_08_15_11_14_04_22438726.jpeg)