Look at these images, the oldest is at the bottom, the newest is at the top, so the drawings are next to time zones are properly set up, so next to the time scale is when the drawing next to it was made.
Avery's experiments showed that bacteria are transformed by “transforming principle” – DNA.
When Griffit in his experiments showed that R-strain bacteria (non-virulent) could be transformed by the heat-killed S bacteria, and become virulent, scientists assumed that there is some kind of “transforming principle” that is involved.
Avery and his colleagues cultured heat-killed S cells and tried t separate cellular components that could possibly be that “transforming principle”. Molecule of DNA gave positive result in a chemical test and also when enzymes able to degrade DNA were introduced, the transforming activity was eliminated.
Answer:
treatment, treatment, control
Indep. Var.
Dep. Var.
Dep. Var
C. Form a new hypothesis and repeat the steps of the scientific method.
