Exam 18: Control of Gene Expression

Use the following scenario to answer the following questions. Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. -If she moves the operator to the far end of the operon (past the transacetylase gene), which of the following would likely occur when the cell is exposed to lactose?

You are given an experimental problem involving control of a gene's expression in the embryo of a particular species. One of your first questions is whether the gene's expression is controlled at the level of transcription or translation. Which of the following might best give you an answer?

In animals, embryonic stem cells differ from adult stem cells in that

The researcher continues to study the reactions of the embryo to these new proteins and you hypothesize that he is most likely to see which of the following (while embryonic genes are still not being expressed)?

In eukaryotes, transcription is generally associated with

In most cases, differentiation is controlled at which level?

Which of the following best describes siRNA?

Steroid hormones produce their effects in cells by

The role of a metabolite that controls a repressible operon is to

The general process that leads to the differentiation of cells is called

The product of the bicoid gene in Drosophila provides essential information about

During DNA replication,

A geneticist introduces a transgene into yeast cells and isolates five independent cell lines in which the transgene has integrated into the yeast genome. In four of the lines, the transgene is expressed strongly, but in the fifth there is no expression at all. Which is a likely explanation for the lack of transgene expression in the fifth cell line?

This is the site in the DNA located near the end of the final exon, encoding an RNA sequence that determines the 3' end of the transcript:

In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than that of adults. This is due to

Allolactose induces the synthesis of the enzyme lactase. An E. coli cell is presented for the first time with the sugar lactose (containing allolactose)as a potential food source. Which of the following occurs when the lactose enters the cell?

What does the operon model attempt to explain?

What would occur if the repressor of an inducible operon were mutated so it could not bind the operator?

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. She tried decreasing the amount of methylation enzymes in the embryonic stem cells and then allowed the cells to further differentiate. Which of the following results would she most likely see?

Since Watson and Crick described DNA in 1953, which of the following might best explain why the function of small RNAs is still being explained?