Answer:
Some substance in the infectious S strain could change the harmless R strain into the more lethal form.
Explanation:
These first type of experiments where crucial to advance in DNA knowledge.
In one experiment, they treated the material with enzymes that destroy all proteins. This is important because scientist notice that there was something else that was causing the strain to change into a lethal form and was heritable (DNA). Know a days we know that plasmids are responsible for such transformation.
White blood cells produce antibodies which fight off the pathogens
Hypertrophy or hypertrophic. Hope that answered your question :)
The correct answer is 4.) Eventually they become separate species
A process of formation of a new species from an existing species is called speciation.
When a single species changed into two or more separate species, is called speciation. Speciation can take place due to reproductive isolation. In reproductive isolation, the separated species no longer can interbreed among themselves. This is happened due to mating differences, sterility or environmental barriers which finally results into the adaptive splitting into two species.