Question

which best summarizes the findings of griffith?
a. cells contain a transforming factor.
b. traits cannot be inherited.
c. all alleles are heterozygous.
d. humans reproduce sexually.

Explanation:

Griffith's experiment showed that a "transforming factor" existed. He used two strains of pneumococcus bacteria. When he injected a combination of heat - killed pathogenic (S - strain) and live non - pathogenic (R - strain) bacteria into mice, the mice died. And he could isolate live S - strain bacteria from the dead mice. This indicated that the R - strain bacteria had taken up some factor (later found to be DNA) from the heat - killed S - strain bacteria. Option B is incorrect as traits are inherited. Option C about alleles being heterozygous is not related to Griffith's work. Option D about human sexual reproduction is also not relevant to Griffith's bacterial transformation experiment.

Answer:

A. Cells contain a transforming factor.