Which scientists discovered that dna has the shape of a double helix?
maurice wilkins and francis crick
erwin chargaff and james watson
james watson and francis crick
rosalind franklin and maurice wilkins

James Watson and Francis Crick

Explanation:

On February 28, 1953 (60 years ago) two scientists from the University of Cambridge made a discovery that would change genetics forever. James Watson and Francis Crick discovered that the structure of DNA was a double helix and everything then made sense. The two won nothing less than the 1962 Nobel Prize in Medicine or Physiology and became known worldwide.

Biochemist Erwin Chargaff, who started research on DNA composition. He found that the composition of DNA nucleotides varied between species, that is, the same nucleotides did not repeat themselves in the same order as proposed by another researcher.

He also demonstrated that the amount of adenine (A) is always similar to the amount of thymine (T), while the amount of cytosine (C) is similar to that of guanine (G). In other words, Chargaff found that the total purines (A + G) and the total pyrimidines (C + T) were generally equal (A + G = C + T). These discoveries were essential for Watson and Crick to assemble the DNA model, as it is known today.

clumped distribution, because you'de have all of the population gathered in a relatively small are.

it's the most common because it provides protection and a mate for reproduction

example: humans, seeweed, cattles, etc.