Exam 18: Regulation of Gene Expression

A researcher introduces double-stranded RNA into a culture of mammalian cells and can identify its location or that of its smaller subsections experimentally, using a fluorescent probe. Some time later, she finds that the introduced strand separates into single-stranded RNAs, one of which is degraded. What does this enable the remaining strand to do?

Which of the following statements about the DNA in one of your brain cells is true?

Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If a researcher moves the promoter for the lac operon to the region between the beta galactosidase (lacZ) gene and the permease (lacY) gene, which of the following results would be most likely?

A genetic test to detect predisposition to cancer would likely examine the APC gene for involvement in which type(s) of cancer?

How are bacteria able to change their patterns of protein synthesis so quickly in response to environmental changes?

Why are BRCA1 and BRCA2 considered to be tumor-suppressor genes?

What would be the result of a mutation in a maternal effect gene in a female Drosophila?

How do steroid hormones produce their effects in cells?

Which of the following statements correctly describes a characteristic of tumor-suppressor gene?

Muscle cells differ from nerve cells mainly because they

What essential information does the product of the bicoid gene in Drosophila provide during development?

Which of the following types of mutation would convert a proto-oncogene into an oncogene?

Altering patterns of gene expression in prokaryotes would most likely serve an organism's survival by ________.

Which axis in the embryo does the protein product of the bicoid gene in Drosophila determine?

Which of the following processes destroys RNA molecules in a cell if they have a sequence complementary to an introduced double-stranded RNA?

In positive control of several sugar metabolism-related operons, the cAMP receptor protein (CRP) binds to DNA to stimulate transcription. Which of the following environmental conditions causes an increase in CRP activity in stimulating transcription?

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. One of her colleagues suggested she try increased methylation of cytosine (C) nucleotides in the DNA of promoters of a mammalian system. Which of the following results would she most likely see?

At the beginning of this century, there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. Many people were surprised that the number of protein-coding sequences was much smaller than they had expected. Which of the following types of DNA make up the rest of the human genome?

Which of the following molecules helps to "turn off" genes in a cell?

How does extracellular glucose inhibit transcription of the lac operon?