Gene Expression Control in Eukaryotic Cells

Which of the following is a mechanism for regulating eukaryotic gene expression in the nucleus?

Alternative splicing (correct)
Protein breakdown regulation
MicroRNA inhibition
mRNA export

What is the function of histone acetyltransferases in chromatin remodeling?

They attract activator proteins
They bind to regulatory sequences
They repress transcription
They add acetyl groups to histone tails (correct)

Which of the following is true about microRNAs (miRNAs)?

They are involved in alternative splicing
They regulate protein breakdown
They are small noncoding RNA molecules (correct)
They bind to histone tails

What is the role of ubiquitin in protein stability regulation?

It marks proteins for destruction (C) Signup and view all the answers

Which of the following is a function of the iron regulatory protein (IRP)?

It blocks ribosome binding (A) Signup and view all the answers

What is the role of the RNA-induced silencing complex (RISC) in gene expression regulation?

It inhibits translation and degrades mRNA (C) Signup and view all the answers

Which of the following is a true statement about alternative splicing?

It generates different proteins from a single gene (C) Signup and view all the answers

What is the function of the glucocorticoid receptor in gene expression regulation?

It binds to the regulatory sequence of genes (B) Signup and view all the answers

How do histone deacetylases affect chromatin structure?

They remove acetyl groups from histone tails (B) Signup and view all the answers

What is the role of the GTP cap on the 5' end of mRNA in gene expression regulation?

If the cap is modified, mRNA is not translated (B) Signup and view all the answers

Which of the following is a method used to identify all mRNAs expressed in certain conditions?

Microarray analysis (A) Signup and view all the answers

What do yellow spots on a DNA microarray indicate?

Equal expression of genes in both conditions (C) Signup and view all the answers

Which of the following is true about the TCA (Krebs) cycle genes?

They are used for ethanol catabolism (D) Signup and view all the answers

Which of the following is true about eukaryotic gene expression control?

Transcriptional control is the most common control point. (A) Signup and view all the answers

What is the purpose of direct sequencing of cDNAs made from mRNA?

To measure gene expression levels (C) Signup and view all the answers

What percentage of genes does a typical cell express?

~20-50% (A) Signup and view all the answers

What is the role of general transcription factors in gene expression?

To assemble preinitiation complexes (D) Signup and view all the answers

Which of the following is true about differentiated cells?

Differentiated cells contain all the genetic information to form a complete organism. (B) Signup and view all the answers

Which type of regulatory protein binds to DNA to switch genes on/off?

Repressor proteins (A) Signup and view all the answers

How can we determine which genes are expressed in certain conditions?

Identifying all mRNAs found in certain conditions using DNA chips (microarrays). (C) Signup and view all the answers

What is the main function of enhancer regions in gene regulation?

To stimulate transcription (B) Signup and view all the answers

What does the intensity of red or green binding to a DNA chip spot indicate?

The number of mRNAs expressed from a specific gene. (C) Signup and view all the answers

In bacterial gene regulation, what happens when the concentration of tryptophan is low?

Genes making enzymes in the tryptophan pathway are expressed (D) Signup and view all the answers

Which of the following is true about the control of gene expression in the human neuron and liver cell?

They have the same genome but express different RNAs and proteins. (A) Signup and view all the answers

How does eukaryotic gene activation occur at a distance?

Through looping of DNA between enhancer and promoter regions (B) Signup and view all the answers

What is the most common control point in eukaryotic gene expression?

Transcriptional control. (C) Signup and view all the answers

What is the effect of acetyl groups on chromatin structure?

They attract proteins that promote transcription (B) Signup and view all the answers

How can a cell change the expression of its genes in response to external signals?

By altering transcriptional control. (A) Signup and view all the answers

What is the purpose of DNA chips (microarrays) in determining gene expression?

To identify all mRNAs found in certain conditions. (B) Signup and view all the answers

What do yellow spots on a DNA chip indicate?

mRNAs from both cells expressed. (C) Signup and view all the answers