BIO 1A03 TEST 2 Revision Questions
With Solutions Scored A+.
The lacZand lacY genes are transcribed when
a) lactose is absent and glucose levels are high.
b)lactose is present and glucose levels are low.
c)lactose is present, regardless of the level of glucose in the cell.
d) glucose levels are low, regardless of the level of lactose in the cell. - Answer b)
The CRP-cAMP complex binds the lactose operon when
a) glucose levels and cAMP levels are low.
b) glucose levels are high and cAMP levels are low.
c) glucose levels and cAMP levels are high.
d) glucose levels are low and cAMP levels are high - Answer d)
As E.coli cells transition from glucose to lactose metabolism when
a) there is an increase in the amount of detectable lactose permease.
b) there is a decrease in the amount of detectable beta-galactosidase.
c) there is an increase in the amount of glucose that is consumed.
d) lactose permease is secreted by the bacterial cell into the environment. - Answer a)
When glucose is no longer available as a nutrient source for bacteria, and lactose becomes the
predominant nutrient source, beta-galactosidase production
a) is regulated at the translational level.
b) is not regulated in any manner.
c) is regulated at the transcriptional level.
d) is regulated at the post-translational level. - Answer c)
, b) post-translational regulation would be the fastest.
c) transcriptional regulation would be the fastest.
d) translational regulation would be the most efficient. - Answer b)
The term gene expression refers to
a) transcription, translation and post-translational modifications of the functional gene product.
b) the process of transcribing DNA into mRNA.
c) the post-translational modifications of a protein.
d) the transcription and subsequent translation of a protein coding gene. - Answer a)
When growing bacterial cells in an environment containing only a limited amount of glucose as
a nutrient source
a) bacterial growth is arrested once all the glucose is depleted.
b) bacterial switch to utilizing lactose as a source of energy.
c) there is no change in bacterial growth once glucose is depleted.
d) bacterial growth is accelerated once all the glucose is depleted. - Answer a)
Housekeeping genes
a) allow for the production of enzymes during changes in cell division.
b) include genes that are important for structural proteins of the cell.
c) are transcribed and translated to bring about changes in cell growth.
d) are expressed on an as-needed basis. - Answer b)
Genes that are turned on and off on an as-needed basis are often referred to as
a) housekeeping genes.
b) constitutively expressed.
c) genes that are required all of the time for normal cellular function.
d) regulated genes. - Answer d)
With Solutions Scored A+.
The lacZand lacY genes are transcribed when
a) lactose is absent and glucose levels are high.
b)lactose is present and glucose levels are low.
c)lactose is present, regardless of the level of glucose in the cell.
d) glucose levels are low, regardless of the level of lactose in the cell. - Answer b)
The CRP-cAMP complex binds the lactose operon when
a) glucose levels and cAMP levels are low.
b) glucose levels are high and cAMP levels are low.
c) glucose levels and cAMP levels are high.
d) glucose levels are low and cAMP levels are high - Answer d)
As E.coli cells transition from glucose to lactose metabolism when
a) there is an increase in the amount of detectable lactose permease.
b) there is a decrease in the amount of detectable beta-galactosidase.
c) there is an increase in the amount of glucose that is consumed.
d) lactose permease is secreted by the bacterial cell into the environment. - Answer a)
When glucose is no longer available as a nutrient source for bacteria, and lactose becomes the
predominant nutrient source, beta-galactosidase production
a) is regulated at the translational level.
b) is not regulated in any manner.
c) is regulated at the transcriptional level.
d) is regulated at the post-translational level. - Answer c)
, b) post-translational regulation would be the fastest.
c) transcriptional regulation would be the fastest.
d) translational regulation would be the most efficient. - Answer b)
The term gene expression refers to
a) transcription, translation and post-translational modifications of the functional gene product.
b) the process of transcribing DNA into mRNA.
c) the post-translational modifications of a protein.
d) the transcription and subsequent translation of a protein coding gene. - Answer a)
When growing bacterial cells in an environment containing only a limited amount of glucose as
a nutrient source
a) bacterial growth is arrested once all the glucose is depleted.
b) bacterial switch to utilizing lactose as a source of energy.
c) there is no change in bacterial growth once glucose is depleted.
d) bacterial growth is accelerated once all the glucose is depleted. - Answer a)
Housekeeping genes
a) allow for the production of enzymes during changes in cell division.
b) include genes that are important for structural proteins of the cell.
c) are transcribed and translated to bring about changes in cell growth.
d) are expressed on an as-needed basis. - Answer b)
Genes that are turned on and off on an as-needed basis are often referred to as
a) housekeeping genes.
b) constitutively expressed.
c) genes that are required all of the time for normal cellular function.
d) regulated genes. - Answer d)
