Question

Use the table to answer the question. In 1928, Frederick Griffith injected four groups of mice with different strains of the bacteria, Streptococcus pneumoniae. The smooth strain had 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. Bacteria After injection with bacteria Group 1 smooth strain mice died Group 2 rough strain mice survived Group 3 heat-killed smooth strain 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? A. A virus carried DNA from the smooth strain to the rough strain. O B. The rough strain took in DNA from the heat-killed smooth strain. O C. The rough strain developed a genetic mutation during binary fission. D. The smooth strain transferred DNA to the rough strain through conjugation.

Answer 1

S STRAIN OF SPTREPTOCOCCUS PNEUMONIAE PRODUCE SMOOTH AND SHINY CLONIES WHEN GROWN IN CULTURE PLATE WHILE R STRAIN PRODUCE ROUGH COLONIES. THIS IS BECAUSE S STRAIN BACTERIA HAS MUCOUS POLYSACCHARIDE WHILE R STRAIN DOESNOT.MICE INFECTED WITH SMOOTH STRAIN DIED AND MICE INFECTED WITH ROUGH STRAIN LIVED.WHEN ROUGH STRAIN MIXED WITH HEAT KILLED S STRAIN MICE DIED MOREOVER GRIFFITH FOUND LIVING S STRAIN BACTERIA FROM DEAD MICE.THIS IS BECAUSE THE ROUGH STRAIN TOOK DNA FROM THE HEAT KILLED SMOOTH STRAIN