Question 84

(Multiple Choice)

Use the following information to answer the questions below.
Yeast is capable of synthesizing the amino acids necessary for survival and can grow on minimal media or enriched media easily.In both conditions,the colonies have a cream colour.The production of adenine is regulated by two genes,ADE1 and ADE2.If either of these genes is defective,adenine cannot be synthesized and the colony will look red (as a result of accumulation of precursors).A common undergraduate lab study is to irradiate yeast cells with ultra violet light from 2-5 sec up to 1-5 minutes,and see what will happen.
-In eukaryotic cells,transcription cannot begin until


A)the two DNA strands have completely separated and exposed the promoter.
B)several transcription factors have bound to the promoter.
C)the 5' caps are removed from the mRNA.
D)the DNA introns are removed from the template.
E)DNA nucleases have isolated the transcription unit.

Answer