6.2 DNA Structure and Function

Question 1

Frederik Meischer

Answer 1

*In 1868, he studied the composition of the nucleus

*Collected pus (mainly WBC) from bandages of his
patients
*He extracted an

“unknown substance” that was acidic

and contained phosphorus
*Called it “nuclein” b/c he found it in the nucleus of WBC

Question 2

Fredrick meischer called the unknown substance

Answer 2

nuclein because he found it in the nucleus of WBC

Question 3

Frederick Griffith studied

Answer 3

studied pneumonia bacteria in 1928

Question 4

What did Frederick Griffith studies accidently shed light on

Answer 4

this accidently shed light on the function of DNA in inheritance

Question 5

Frederick Griffith used 2 different strains of pneumonia bacteria

Answer 5

1. S-strain (smooth) – contained a capsule that made colonies look smooth/glossy
2. R-strain (rough) – did not have capsule that made colonies look rough/irregular

Question 6

How did Frederick study pneumonia

Answer 6

Injected mice with S-strain → mice died of pneumonia

• Injected mice with R-strain → no signs of pneumonia
• Concluded, the capsule made the bacteria highly virulent (pathogenic)