AP Biology - Gene Expression

What is the corresponding codon for AGT?

• UCA
• TCA
• UGA
• ACU

Which of the following does not occur in prokaryotic gene expression but does occur in eukaryotic gene expression?

• mRNA, tRNA, and rRNA are transcribed
• RNA polymerase binds to the promotor
• a poly-A tail is added to the ends of the mRNA
• Transcription can begin as soon as translation has begun even alittle

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

• the protein  product of the promotor
• start and stop codons
• ribosomes and tRNA
• several transcription factors

Which of the follwoing best describes the significance of the TATA box in eukaryotic promoters?

• it is the recognition site for a specific transcription factor
• it sets the reading frame of the mRNA
• it is the recognition site for ribosomal binding
• it signals the end of the nucleotide sequence of the gene

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 

What is the effect of a nucleotide-pair substitution that results in a nonsense mutation in a gene?

• it changes an amino acid in the encoded protein
• It has no effect on the amino acid sequence of the encoded protein
• it introduces  premature stop codon into the mRNA
• it alters the reading frame of the mRNA

Tags

NGSS.HS-LS3-2

Which is the best description of a gene?

• a DNA sequence that is expressed to form a functional product; either RNA or polypeptide
• a DNA subunit that codes for a single complete protein
• a DNA-RNA sequence combination that results in an enzymatic product
• a descrete unit of hereditary information that consists of a sequence of amino acids 

Tags

NGSS.HS-LS1-1

A tRNA (#1) attached to the amino acid lysine enters the ribosome.  The lysine binds to the growing polypeptide on the other tRNA (#2) already in the ribosome. Where does tRNA (#2 move to next?

• A site
• P site
• E site
• exit tunnel

Where does transcription in prokaryotes occur?

• nucleus

• cytosol

• ribosome

• nucleolus

Protein 1, 2 and 3 all were translated from Gene A. This is an example of....

• mutations

• alternative splicing

• transcription

• cancer