EBIO 2070 Exam 2 Questions and Correct
Answers
Which of the following is true about all the non-sex cells in your body?
A. The cells are all genetic clones of each other
B. The cells are all produced by mitosis
C. The cells all look and function exactly the same
A and B
Every cell in our body has the same...
Genome (set of genes)
What proteins do different cell types express?
Muscle cells express actin and myosin, hair and nail cells express keratin, nerve cells express
neurotransmitters, blood cells express hemoglobin
Why does a neuron look different from a muscle cell?
The neuron has different proteins
Differential gene expression
Results in different cell types expressing (transcribing and translating) different proteins; a cell's
structure and function are defined by which genes it turns off and which genes it turns on
How does gene regulation allow cells and organisms to respond to their environment?
, Controls what genes are transcribed and translated into proteins and how much of a protein is
made (ex: insulin is a protein hormone expressed in response to increased blood sugar that tells
fat cells to take up glucose)
Regulation of gene/protein expression can occur at what levels?
Transcription, pre-mRNA processing (splicing), mRNA degradation, translation, post-
translational modifications to proteins, and protein degradation
Cis-regulatory elements
DNA sequences on the same piece of DNA as a gene that regulates transcription of the gene (ex:
enhancers and promoters)
Enhancers
Consist of many short DNA sequences (4-12 nucleotides) called transcription factor binding sites
(TBSs); often located hundreds of thousands of bp from transcriptional start and first exon
What are enhancers needed for?
Expression in specific tissues/cell types at a specific time; to promote transcription of a gene
Transcription factors and enhancers
A transcription factor usually has several potential TBSs and usually binds the enhancer in
several places; several kinds of transcription factors will bind to a given enhancer; usually
several enhancers for each gene
How do TFs stabilize their binding to the enhancer?
They bind to each other
Answers
Which of the following is true about all the non-sex cells in your body?
A. The cells are all genetic clones of each other
B. The cells are all produced by mitosis
C. The cells all look and function exactly the same
A and B
Every cell in our body has the same...
Genome (set of genes)
What proteins do different cell types express?
Muscle cells express actin and myosin, hair and nail cells express keratin, nerve cells express
neurotransmitters, blood cells express hemoglobin
Why does a neuron look different from a muscle cell?
The neuron has different proteins
Differential gene expression
Results in different cell types expressing (transcribing and translating) different proteins; a cell's
structure and function are defined by which genes it turns off and which genes it turns on
How does gene regulation allow cells and organisms to respond to their environment?
, Controls what genes are transcribed and translated into proteins and how much of a protein is
made (ex: insulin is a protein hormone expressed in response to increased blood sugar that tells
fat cells to take up glucose)
Regulation of gene/protein expression can occur at what levels?
Transcription, pre-mRNA processing (splicing), mRNA degradation, translation, post-
translational modifications to proteins, and protein degradation
Cis-regulatory elements
DNA sequences on the same piece of DNA as a gene that regulates transcription of the gene (ex:
enhancers and promoters)
Enhancers
Consist of many short DNA sequences (4-12 nucleotides) called transcription factor binding sites
(TBSs); often located hundreds of thousands of bp from transcriptional start and first exon
What are enhancers needed for?
Expression in specific tissues/cell types at a specific time; to promote transcription of a gene
Transcription factors and enhancers
A transcription factor usually has several potential TBSs and usually binds the enhancer in
several places; several kinds of transcription factors will bind to a given enhancer; usually
several enhancers for each gene
How do TFs stabilize their binding to the enhancer?
They bind to each other
