c. discovered that DNA-digesting enzymes prevented bacterial transformation
d. the first to build an accurate model of DNA and to describe it explicitly in a
publication
e. the first to demonstrate, through the use of radioactive isotopes, that DNA, not
protein, is the genetic material
f. provided two important clues to the structure of DNA; one clue is that A = T and the
other is that C = G
g. discovered the structure of collagen
h. obtained excellent X-ray diffraction photographs that suggested that DNA was a
long, thin molecule with regularly repeating units
The unique feature of HeLa cells that make them important for research is that
a. they are identical to all other human cells.
b. they are immortal cells and will grow in culture.
c. they are limited in growth cycles.
d. they are like stem cells.
e. all of these make them important.