AP Bio Final Review: DNA, Protein Synthesis, Gene Expressio

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

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 

Which of the following events in translation is the first to occur in eukaryotes?

• elongation of the polypeptide
• base pairing of activated methionine-tRNA to AUG of the messenger RNA
• binding of the larger ribosomal subunit to smaller ribosomal subunits
• the small subunit of the ribosome recognizing and attaching to the 5'cap

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

Which is an example of a gene SUBSTITUTION mutation?

• TAC -> AGG

• TAC-> AU

• TAC -> AUUG

• TAC -> AUG

Tags

NGSS.HS-LS3-2

Seals the Okazaki fragments together

• DNA Polymerase
• ligase
• helicase
• primase

Enzyme that unwinds the DNA

• ligase
• DNA Polymerase
• primase
• helicase

Cells must control gene expression so that

• their genes will be expressed only when needed

• their genes will always be expressed

• their genes will never be expressed

• genetic disorders can be corrected

Tags

NGSS.HS-LS1-1