chapter 14

Question 1

What was the key finding in Griffiths experiments using live and heat killed pathogenic bacteria?

Answer 1

Genetic information can be transferred from dead to live bacteria

Question 2

Describe Nature of DNA base parings? Which nitro bases are RNA ONLY?

Answer 2

Adenine- Thymine (2 bonds)
Cytosine- Guanine (3 bonds)
Hydrogen bonds

URACIL is RNA only
RNA is single strand

Question 3

Chargaff’s rule?

Answer 3

Amount of A=T

Amount of C=G

Question 4

Bonds that hold complimentary strands of DNA together

Answer 4

Hydrogen Bonds

Question 5

Bonds holding DNA backbone together

Answer 5

Phosphodiester Bonds

Question 6

Basic mechanism of DNA replication is _____ with one ____ strand and one ____ strand

Answer 6

Semi conservative, one new strand , one old strand

Question 7

Common feature of all DNA polymerases is that

Answer 7

they synthesize from 5’-3’ direction

Question 8

What are features of the watson crick model?

Answer 8

Hydrogen bonds between bases
Phosphodiester backbone
Double Helix
Anti parallel strands

Question 9

Function of DNA polymerases

Answer 9

DNA pol 3- replicate
DNA pol 1 replaces RNA primer w DNA
DNA pol 2- DNA Repair

Question 10

Hershey and Chase used radioactive sulphur and phos to ______

Answer 10

Differentially label DNA and Protein

Question 11

Meselson and Stahl used a density label to _____

Answer 11

Tell between new and old DNA strands (new dna lighter)

Question 12

The difference in leading strand vs lagging strand synthesis is a consequence of ____

Answer 12

DNA structure and action of polymerase

Question 13

DNA Ligase function

Answer 13

Joins okazaki fragments to complete strands

Question 14

Synthesis of telomeres

Answer 14

requires telomerase which uses internal rna as a template