A DNA molecule is a twisted ladder-like stack of building blocks called nucleotides. There are four types of DNA nucleotides-adenine, cytosine, guanine, and thymine-or A, C, G, and T, for short.ou've got six billion of these pairs of nucleotides in each of your cells, and amongst these six billion nucleotide pairs are roughly 23,000 genes.
Where does lightning occur?This map from NASA shows color variations indicating the average annual number of lightning flashes per square kilometer. WhereThe new maps show that Florida, for example, is one place where the rate of strikes is unusually high. This is because Florida experiences two sea breezes: one from the east coast and one from the west coast.
(Reuters) In the first half of the 20th century, hundreds of Americans died each year from lightning strikes. The data is messy, but in the years from about 1920 to the middle of the 1940s, about 400 people were killed by lightning annually. Last year, 23 did, the fewest on record.