Ch. 9 DNA & Function

Question 1

DNA vs. RNA

Answer 1

DNA: stores instructions of the genetic code
RNA: transcribes and translates the genetic code to make proteins

Question 2

what did Johann Miescher do in 1868?

Answer 2

isolated an organic acid that was rich in phosphorus that he guessed was the genetic material
- called it a nuclein

Question 3

What did Chargaff do in 1949?

Answer 3

showed:

• A pairs with T, held together by a double bond
• C pairs with G, held together by a triple bond

Question 4

Chargaff’s rule

Answer 4

• the amount of adenine is the same as the amount of thymine

- the amount of cytosine is the same as the amount of guanine

Question 5

the structure of DNA

Answer 5

each nucleotide of DNA strand consists of

• deoxyribose sugar
• phosphate group
• nitrogen base (A,T,C,G)

Question 6

what did Rosalind Frank do in 1953)

Answer 6

showed DNA had a helix structure through her X-ray crystallography