Question 1
Select one answer.
CRP protein binds to the lac operon under conditions of low glucose. Its role in the expression of genes in the lac operon is:
A. to transcribe DNA to mRNA for the structural genes in the operator.
B. It increases the binding of lactose to the lac repressor, causing it to be released from the operator.
C. It enhances the binding of RNA polymerase to the lac operon, increasing transcription
D. It bumps the lac repressor off the DNA, allowing transcription of the genes for lactose metabolism.
Question 2
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Which of the following refers to variations in the same gene, which result in different phenotypes?
A. Chromosome
B. DNA
C. Allele
D. Genotype
Question 3
Select one answer.
When bacteria are grown in lactose they produce enzymes required for lactose metabolism. When placed in glucose, these enzymes are no longer produced. The expression of these genes is likely due to:
A. Uncondensing of the DNA, to allow for expression of the genes.
B. mutations accumulated in the regulatory region of the gene that code for lactose metabolizing enzymes.
C. Changing the behavior of a DNA binding protein that regulates expression of these genes.
Question 4
Select one answer.
Eukaryotic DNA is packaged into nucleosomes due to the action of
A. histones
B. DNA helicases
C. repressor proteins
D. RNA polymerases
Question 5
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In what type of cell do genes contain exons which are interrupted by introns, that are spliced out after transcription.
A. Prokaryotic
B. Eukaryotic
C. Both prokaryotic and eukaryotic cells.
Question 6
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Assuming that the genes required for sucrose (table sugar) degradation are contained within an operon, then under conditions of low sucrose, you would expect:
A. The repressor protein to bind to the operator, preventing transcription.
B. The repressor protein to bind to the operator, allowing transcription.
C. The repressor protein released from the operator, allowing transcription.
D. The repressor protein released from the operator, preventing transcription.
Question 7
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Which of the following represents a change that CANNOT be passed on to the next generation?
A. Changes in gene expression due to increased production of a hormone.
B. Changes in DNA packaging leading to gene silencing.
C. Changes in DNA sequence due to exposure to radiation.
D. None of the above, they are all heritable changes.
Question 8
Select one answer.
DNA resides in the nucleus of the cell in a prokaryotic cell, but not a eukaryotic cell.
A. True
B. False