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Author Question: The first genes on Earth were probably A) DNA produced by reverse transcriptase (Read 484 times) |
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Each year in the United States, there are approximately six million pregnancies. This means that at any one time, about 4% of women in the United States are pregnant.
The most dangerous mercury compound, dimethyl mercury, is so toxic that even a few microliters spilled on the skin can cause death. Mercury has been shown to accumulate in higher amounts in the following types of fish than other types: swordfish, shark, mackerel, tilefish, crab, and tuna.
Since 1988, the CDC has reported a 99% reduction in bacterial meningitis caused by Haemophilus influenzae, due to the introduction of the vaccine against it.