chapter 10 control of gene expression

A chemical modification of DNA that does not affect the nucleotide sequence of a gene but makes that gene less likely to be expressed.

• methylation
• acetylation
• transcription
• translation

Tags

NGSS.HS-LS3-2

Which of the following is an example of post-transcriptional control of gene expression?

• the addition of methyl groups to cytosine bases of DNA
• the binding of transcription factors to a promoter
• the removal of introns and splicing together of exons
• gene amplification contributing to cancer

The parts of a gene that do NOT code for amino acids in a protein are called

• introns
• exons
• codons
• anticodons

What is the function of the poly-A tail in mRNA?

• to add modified guanin to the 3' end of the mRNA
• to indicate the site of translational termination
• to code for the binding of RNA polymerase to the DNA
• to help protect the mRNA from degradation by hydrolytic enzymes 

The production of mature mRNA in eukaryotes involves

• cutting introns out and spicing exons together
• adding the 5' cap
• adding the 3' poly A tail
• all of these are correct

A protein that binds to the operator and blocks the RNA polymerase

• regulator
• repressor
• activator
• corepressor

What must happen to a newly made polypeptide before it can be secreted from a cell?

• it must be translated by a ribosome that remains free of attachment to the ER
• its signal sequence must target it to the ER, after which it goes to the Golgi
• Its signal sequence must be cleaved off
• Its signal sequence must target it to the plasma membrane

Translation is crucial to the process of making proteins. Which statement best describes what takes place during translation? 

• A copy of chromosomal DNA is created 
• Information in mRNA is converted into a sequence of amino acids in a protein 
• A RNA copy of a DNA strand is made.
  
• Instructions from DNA in the nucleus are brought to the cytoplasm 

Tags

NGSS.HS-LS1-1

The "on/off" switch for an operon is called the

• promoter
• repressor
• operator
• gene

what is an operon?

• a part of a ribsome
• a part of a Rna
• a unit made up of linked genes that code for proteins needed to do a specific task
• needed for dna replication