Biology 2015

In regulation of the lac operon, when lactose is present and glucose is absent,
a. there is a low level of cAMP present.
b. there is a high level of cAMP present.
c. transcription of structural genes occurs.
d. transcription of lactose occurs.
e. Both b and c are correct.

In regulation of the trp operon, when tryptophan is present,
a. the repressor is able to bind to the operator.
b. the repressor is unable to bind to the operator.
c. transcription of the repressor in inhibited.
d. transcription of the structural genes, operator, and promoter occurs.

In operon models, the function of the promoter is to
a. code for the repressor protein.
b. bind with RNA polymerase.
c. bind to the repressor.
d. code for the regulator gene

Label this diagram of an operon.

Which of the following regulate(s) gene expression in the eukaryotic nucleus?
a. posttranslational control
b. transcriptional control
c. translational control
d. posttranscriptional control
e. Both b and d are correct.

Which of the following mechanisms may create multiple mRNAs from the same gene?
a. posttranslational control
b. alternative mRNA splicing
c. binding of a transcription factor
d. chromatin remodeling
e. miRNAs

Translational control of gene expression occurs within the
a. nucleus.
b. cytoplasm.
c. nucleolus.
d. mitochondria.

Barr bodies are
a. genetically active X chromosomes in males.
b. genetically inactive X chromosomes in females.
c. genetically active Y chromosomes in males.
d. genetically inactive Y chromosomes in females

A mutation in a DNA molecule involving the replacement of one nucleotide base pair with another is called a(n)
a. frameshift mutation.
b. transposon.
c. deletion mutation.
d. base substitution.
e. insertion mutation

THE COW ATE THE HAY. If the letter C is deleted from this sentence, shifting the reading frame, we read THE OWA TET HEH AY. Which of the following mutations best explains this example?
a. spontaneous mutation
b. frameshift mutation
c. induced mutation
d. base substitution
e. transposon

A cell is cancerous. You might find an abnormality in
a. a proto-oncogene.
b. a tumor suppressor gene.
c. regulation of the cell cycle.
d. tumor cells.
e. All of these are correct.

A tumor suppressor gene
a. inhibits cell division.
b. opposes oncogenes.
c. prevents cancer.
d. is subject to mutations.
e. All of these are correct.