Question

After mixing a heat-killed, phosphorescent (light-emitting) strain of bacteria with a living, nonphosphorescent strain, you discover that some of the living cells are now phosphorescent. Which observation(s) would provide the best evidence that the ability to phosphoresce is a heritable trait?A) DNA passed from the heat-killed strain to the living strain. B) Protein passed from the heat-killed strain to the living strain. C) The phosphorescence in the living strain is especially bright. D) Descendants of the living cells are also phosphorescent. E) Both DNA and protein passed from the heat-killed strain to the living strain.

Answer 1

Answer:

The correct answer is A)  DNA passed from the heat-killed strain to the living strain.

Explanation:

Griffith's in 1928 showed that a virulent strain of heat-killed bacteria when mix with a non-virulent strain of bacteria then the non-virulent bacteria transforms into virulent bacteria. Later it was proved that DNA was the material that transfers from virulent strain to non-virulent strain and transform it into virulent strain.

So as DNA is the genetic material that passes from one generation to another and one bacteria to another not protein therefore after mixing a heat-killed phosphorescent strain of bacteria with non-phosphorescent living strain, DNA must be passed to living strain from heat-killed strain to gain phosphorescent ability.

Therefore the right is A)  DNA passed from the heat-killed strain to the living strain.