A

Question

In 1928, Frederick Griffith injected four groups of mice with different strains of the bactena, Streptococcus pneumoniae. The smooth atrain nad a polysaccharide capsule that protected the bacteria from the mouse's immune system. The rough strain did not have this capsule The details of each group and the results of the experiment are shown in the table below

Use the table to answer the question.

Bacteria

After injection with bacteria

mice died

mice survived

mice survived

Group 4 rough strain mixed with heat-killed smooth strain mice died

Which conclusion about Group 4 is MOST strongly supported by the results of the experiment?

(1 point)

A virus carned DNA from the smooth strain to the rough strain.

The rough strain took in DNA from the heat-killed smooth strain.

The rough strain deveroped a genetic mutation during binary fission

The smooth strain transferred DNA to the rough sirain through conjugation

Group 1 smooth strain

Group 3 heat-killed smooth strain

Group 2 rough strain

Answer 1

The conclusion that is most strongly supported by the results of the experiment is that the rough strain took in DNA from the heat-killed smooth strain. This is because in Group 4, where the rough strain was mixed with heat-killed smooth strain, the mice died. This suggests that the rough strain somehow acquired the genetic material from the heat-killed smooth strain, leading to a change in its virulence.