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Author Question: What is thought to aid the proliferation and spread of hydrothermal vents? A) Seep communities B) ... (Read 56 times) |
The human body produces and destroys 15 million blood cells every second.
Liver spots have nothing whatsoever to do with the liver. They are a type of freckles commonly seen in older adults who have been out in the sun without sufficient sunscreen.
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.
Signs of depression include feeling sad most of the time for 2 weeks or longer; loss of interest in things normally enjoyed; lack of energy; sleep and appetite disturbances; weight changes; feelings of hopelessness, helplessness, or worthlessness; an inability to make decisions; and thoughts of death and suicide.
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.