Question 17N.3.HL.TZ0.03
| Date | November 2017 | Marks available | [Maximum mark: 4] | Reference code | 17N.3.HL.TZ0.03 |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Describe, State | Question number | 03 | Adapted from | N/A |
The Hershey and Chase experiment supported DNA as the hereditary material. Describe the experiment.
[3]
a. radioactive isotopes used to label viruses/bacteriophages/phages
b. proteins labelled with radioactive sulphur/35S and DNA labelled with radioactive
phosphorous/32P
c. phage infects bacterium
d. only viral DNA enters bacterium «viral coat/capsid/shell do not»
e. parts of phage remaining outside bacterial cell are removed
OR
bacteria are separated from phage parts «by centrifuge»
f. bacteria contain the labelled/radioactive DNA
[Max 3 Marks]
Some regions of DNA act as telomeres or produce tRNA. State one other function of DNA sequences that do not code for protein.
[1]
a. regulate gene expression
b. act as promoter
c. role in chromosome pairing/crossing over/recombination
d. introns
OWTTE
[Max 1 Mark]
