Question

A heat-killed, phosphorescent (light-emitting) strain of bacteria is mixed with a living, non-phosphorescent strain. Further observations of the mixture show that some of the living cells are now phosphorescent. Which of the following observations would provide the best evidence that the ability to phosphoresce is a heritable trait?

Answer 1

B. DNA passed from the heat-killed strain to the living strain.

Step-by-step explanation:

This is similar to Grifitth's transformation experiment which uses 2 different strains of Streptococcus pneumoniae.

Pieces of DNA from the heat-killed strain must have been taken up by the living strain and this pieces became incorporated into the genome of the living strain. Th DNA pieces contained the phosphoresce gene and this gene was passed on to the living strain in the process of taking up the DNA.

The correct option is B.