James D.Watson(left)and Francis Crick propose a double- helical structure for DNA.(1953 1962諾貝爾生醫类 cis Crick James D.Watson Frederick Wilkins 20 20 Francis Crick James D. Watson Frederick Wilkins 1962 諾貝爾生醫獎 James D. Watson (left) and Francis Crick propose a double￾helical structure for DNA. (1953)