HW10

How do steroid hormones, such as estrogen, modulate genome expression in responsive cells? 1.by binding to enhancer sequences 2.by binding to receptors in the cell membrane, the signal is then transduced to the nucleus through a signaling pathway 3.by binding to receptors in the cytoplasm which then migrate to the nucleus where they bind to DNA to regulate genome expression 4.by binding to receptors in the nucleus that are activated and then bind to DNA to regulate genome expression

3

The yeast Rap1 protein initiates formation of heterochromatin by binding to: 1.deacetylated histone H2A 2.methylated histone H1 3.specific target sequences in the DNA 4.random target sequences in the DNA

3

The trp attenuator is located 1.Between the trpC and trpB genes in the operon 2.In the 3' UTR of the operon 3.In the promoter region of the trp operon prior to any coding region 4.Between the promoter region and the trpE gene in the operon

4

How do Eukaryotic regulatory co-activator and co-repressor complexes associate with DNA? a. They are recruited by sequence-specific DNA binding proteins b. They are recruited by non-specific DNA binding proteins c. They bind directly to specific sequences of DNA d. They bind directly to DNA, but not to specific sequences

A

How does a riboswitch affect the transcription of a downstream RNA? A. The riboswitch changes conformation of the expression platform upon binding a metabolite B. The riboswitch changes conformation upon binding a target sequence C. The riboswitch permanently binds the target upon binding of a metabolite D. The riboswitch changes conformation of the aptamer domain upon binding a metabolite

A

Which of the following is the main reason that a typical eukaryotic gene is able to respond to a far greater variety of regulatory signals than a typical prokaryotic gene or operon? A. The transcription of a eukaryotic gene can be influenced by proteins that bind far from the promoter. B. Eukaryotes have three types of RNA polymerase. C. Eukaryotic RNA polymerases require general transcription factors. D. Prokaryotic genes are packaged into nucleosomes.

A

In eukaryotes, methylation of DNA a.occurs on the 5 position of the C in CG dinucleotides and is correlated with gene activation b.occurs on the 5 position of the C in CG dinucleotides and is correlated with gene inactivation c.occurs only on the maternal allele d.occurs randomly in genomic DNA

B

Riboswitches regulate transcription by a. controlling whether promoter clearance occurs or not b. controlling whether sigma factor binds promoter or not c. controlling whether ribosome binding occurs or not d. controlling whether intrinsic terminator stem-loop forms or not

d

Antitermination is involved in the regulation of which of the following? A. Genes present in the upstream region of the operon B. Operons encoding enzymes involved in the biosynthesis of amino acids with regulation dependent on the concentration of the amino acids C. Genes present in the downstream region of the operon D. Operons encoding enzymes involved in the degradation of metabolites, regulation dependent on the presence of the metabolite

C