a) Endoplasmic reticulum
c) Golgi apparatus
b) Peptide bond formation
a) The small subunit of the ribosome binds to the 5′ cap on the mRNA.
b) The large ribosomal subunit joins the complex.
c) An aminoacyl tRNA binds to the start codon.
d) A peptide bond is formed between two adjacent amino acids.
a) The polypeptide chain grows by one amino acid.
b) The ribosome slides one codon down the mRNA.
c) The two ribosomal subunits are joined in a complex.
d) The completed polypeptide is released from the ribosome.
a) aminoacyl-tRNA synthetase
d) argininosuccinate lyase
a) tRNAs are double-stranded.
b) Each tRNA binds a particular amino acid.
c) There are four types of tRNA.
d) tRNAs carry special sequences known as codons.
e) All of the above
a) The small ribosomal subunit binds to the mRNA.
b) The tRNA bearing methionine binds to the start codon.
c) The large ribosomal subunit binds to the small one.
d) The start codon signals the start of translation.
e) All of the above.
e) either UAA or TAA, depending on first base wobble.
a) bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.
b) bonding of the anticodon to the codon.
c) binding of ribosomes to mRNA.
d) attachment of amino acids to tRNAs.
e) shape of the A and P sites of ribosomes.
a) the ribosome will skip a codon every time a UUU is encountered.
b) proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU.
c) none of the options will occur; the cell will recognize the error and destroy the tRNA.
d) the cell will compensate for the defect by attaching phenylalanine to tRNAs with lysine-specifying anticodons.
e) none of the proteins in the cell will contain phenylalanine.
a) an assembled ribosome with a polypeptide attached to the tRNA in the P site
b) separated ribosomal subunits, a polypeptide, and free tRNA
c) separated ribosomal subunits with a polypeptide attached to the tRNA
d) a cell with fewer ribosomes
e) an assembled ribosome with a separated polypeptide
A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) in the ribosome already.
Where does tRNA #2 move to after this bonding of lysine to the polypeptide?
a) A site
b) exit tunnel
c) E site
d) directly to the cytosol
e) P site
a) A deletion mutation results in the loss of a base in the DNA sequence.
b) A knock-out mutation results in a total absence of the mutated protein.
c) Addition and deletion mutations disrupt the primary structure of proteins.
d) An addition mutation results in an added base in the DNA sequence.
a) Both addition and deletion.
a) One addition and two deletion mutations.
b) One addition mutation.
c) One deletion mutation.
d) One addition and one deletion mutation.
a) An addition mutation and a deletion mutation.
b) An addition mutation
c) A deletion mutation.
a) a deletion of a codon
b) a substitution of the third nucleotide in an ACC codon
c) a deletion of 2 nucleotides
d) a substitution of the first nucleotide of a GGG codon
e) an insertion of a codon
a) It changes an amino acid in the encoded protein.
b) It alters the reading frame of the mRNA.
c) It introduces a premature stop codon into the mRNA.
d) It has no effect on the amino acid sequence of the encoded protein.
e) It prevents introns from being excised.
a) a base deletion only.
b) either an insertion or a deletion of a base.
c) a base insertion only.
d) deletion of three consecutive bases.
e) a base substitution only.
a) a point mutation
b) a codon deletion
c) a codon substitution
d) a base-pair deletion
e) a substitution in the last base of a codon
a) a DNA – RNA sequence combination that results in an enzymatic product
b) a discrete unit of hereditary information that consists of a sequence of amino acids
c) a unit of heredity that causes formation of a phenotypic characteristic
d) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide
e) a DNA subunit that codes for a single complete protein
a) several transcription factors have bound to the promoter.
b) the two DNA strands have completely separated and exposed the promoter.
c) the 5′ caps are removed from the mRNA.
d) the DNA introns are removed from the template.
e) DNA nucleases have isolated the transcription unit.
a) have unique ribosomes.
b) have different chromosomes.
c) use different genetic codes.
d) contain different genes.
e) express different genes.
a) RNA polymerase
a) 30-nanometer fiber
d) Promoter-proximal elements
c) TATA box
d) Promoter-proximal element
a) Basal transcription factors form a basal transcription complex.
b) TBP is recruited to the promoter.
c) Regulatory transcription factors bind to enhancers.
d) RNA polymerase binds to the promoter of the gene.
a) alter the pattern of DNA splicing
b) promote recombination
c) help RNA polymerase transcribe certain genes
d) unwind the DNA so that its genes can be transcribed
e) cause mutations in the DNA
a) DNA acetylation and methylation.
b) histone amplification and DNA acetylation.
c) DNA methylation and histone modification.
d) DNA amplification and histone methylation.
e) DNA methylation and histone amplification.
a) are required for the expression of specific protein-encoding genes.
b) bind to other proteins or to a sequence element within the promoter called the TATA box.
c) usually lead to a high level of transcription even without additional specific transcription factors.
d) inhibit RNA polymerase binding to the promoter and begin transcribing.
e) bind to sequences just after the start site of transcription
a) protein-based hormones
e) other transcription factors
a) degrading proteins as soon as they are formed
b) inhibiting the catalytic activity of rRNA
c) binding to mRNAs and degrading them or blocking their translation
d) seeking out viral DNA and destroying it
e) binding to DNA and preventing transcription of certain genes
a) RNA obstruction.
b) RNA interference.
c) RNA targeting.
d) RNA disposal.
e) RNA blocking.