Key to practise exam 2
Exam 2, total points=100, Each choice question was valued 2 points. Essay was valued at 8 points. Exam scores are posted on the Online Gradebook.
Test Analysis- The exam was curved upwards by 6 points. With the curve the average and median were 75. The average is at the C+/B border. It is advised that you careful analyze your response to the difficult questions if you response was incorrect.
1=E, 2=D, 3=C, 4=B, 5=C, 6=C, 7=B, 8=C, 9=C, 10=C, 11=A, 12=A, 13=D, 14=B, 15=C, 16=A, 17=B, 18=A, 19=C, 20=B, 21=A, 22=C, 23=C, 24=C, 25=B, 26=A, 27=C, 28=B, 29=B, 30=A, 31=B, 32=C, 33=C, 34=D, 35=B, 36=C, 37=B, 38=B, 39=A, 40=A, 41=B, 42=A, 43=B, 44=B, 45=B, 46=A
Essay
| SAGE | Microarray |
| mRNA level is measured by sequencing cDNA tags | mRNA level is measured by hybridization of cDNA to probes fixed to a slide |
| the technique is laborious | The technique is comparatively faster |
| no hybridization so no optimization is required | hybridization must be optimized |
| no bias since sequence tags reveal which genes are expressed | biased because an investigator chooses what probes are fixed to slide |
| deep detection limit determined by the amount of sequence obtained | detection limited by the hybridization signal |