Answer:
I think the answer is option 3
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.
One of the most intelligent invertebrate animal is the octopus. These animals belong to the cephalopod class of molluscs. These animals demonstrate relatively complex reasoning especially when capturing prey. They also demonstrate their intelligence by their communicating skills and some even show signs of learning.