Exam 28: Regulation of Gene Expression

Draw a simple map of the lactose operon indicating the relative positions of promoter,operator,CRP-binding site,repressor gene (I),and the structural genes of the operon (A,Y,Z).Indicate where the CRP protein binds within this operon.When it is bound to this site,does the CRP protein have a positive or negative effect on gene expression in this system?

In the development of the fly Drosophila,homeotic genes:

Which of the following statements correctly describes promoters in E.coli?

The SOS response in E.coli is triggered by extensive damage to the cell's DNA and increases the capacity for repairing such DNA.What molecular events bring about expression of the SOS genes?

Which one of the following classes is expressed in the unfertilized egg and is involved in directing the spatial organization of the Drosophila embryo early in development?

By mutating selected bases in sequence 3 in the leader peptide of the trp operon of E.coli,attenuation compared to the normal sequence is:

Which of the following base pairs have a potential H-bond donor in both the major and minor grooves?

Small signal molecules that regulate transcription are not known to:

By increasing the spacing between sequence 1 and sequence 2 in the leader peptide of the trp operon of E.coli,attenuation compared to the normal sequence is:

Which of the following statements is true of the attenuation mechanism used to regulate the tryptophan biosynthetic operon in E.coli?

Define each in one to two sentences: (a)heterochromatin (b)euchromatin (c)chromatin remodeling.

Name and contrast the four different types of stem cells found in humans.

Which of the following statements about regulation of the lac operon is true?

Which one of the following classes of genes is involved in specifying the localization of organs in the Drosophila embryo?

Attenuation in the trp operon of E.coli:

Match the molecule with its role in the lac operon.Note that a given molecule may have more than one role. -

Describe three different mechanisms by which riboswitches can modulate mRNA.

Which of the following is a DNA sequence?

Which one of the following statements about eukaryotic gene regulation is correct?