evidence of transformation

Question 1

S (virulent) strain

Answer 1

1. Living encapsulated bacteria injected into mouse
2. mouse died
3. colonies of encapsulated bacteria were isolated from dead mouse

S colonies

Question 2

R (avirulent) strain

Answer 2

1. Living nonencapsulated bacteria injected into mouse
2. mouse remained healthy
3. a few colonies of nonencapsulated bacteria were isolated from mouse; phagocytes detroyed nonencapsulted bacteria

R colonies

Question 3

Dead S (virulent) strain

Answer 3

1. heat killed encapsulated bacteria injected into mouse
2. mouse remained healthy
3. no colonies were isolated from mouse

no colonies

Question 4

Dead S + R strains

Answer 4

1. Living nonencapsulated and heat-killed encapsulated bacteria injected into mouse
2. mouse died
3. colonies of encapsulated bacteria were isolated from dead mouse

S & R colonies