Module 13 Practice Questions: Genes and Proteins
Use the figure to answer the question. A---> B--->C The figure shows a simple metabolic pathway. How many genes are necessary for this pathway?
2
How many bases are in a codon?
3
Determine the 3'-->5' sequence of the anticodon on the tRNA for the following codon sequence: Serine, 5'-AGU-3'
3'-UCA-5'
Which of the following sequences of nucleotides are possible in the template strand of DNA that would code for the polypeptide sequence Phe-Leu-Ile-Val?
3′-AAA-GAA-TAA-CAA-5′
A particular triplet of bases in the template strand of DNA is 5′-AGT-3′. What would be the corresponding codon for the mRNA that is transcribed?
3′-UCA-5′
The template strand of a given gene includes the sequence 3′-GCCACGTATCA-5′. What is the sequence of the nontemplate strand?
5′-CGGTGCATAGT-3′
Which of the following processes occurs in eukaryotic gene expression?
A cap is added to the 5′ end of the mRNA.
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true?
A gene from an organism can theoretically be expressed by any other organism.
During a normal translation cycle, where would you expect to find a tRNA attached to a single amino acid?
A site
Codons are three-base sequences in mRNA that specify the addition of a single amino acid to the growing protein chain during translation. How do eukaryotic codons and prokaryotic codons compare?
Codons are a nearly universal language among all organisms.
Which of the following molecules functions to transfer genetic information from one generation to the next?
DNA
All of the following are directly involved in translation EXCEPT:
DNA.
Which of the following best illustrates the central dogma of biology?
DNA→RNA→Protein
Prokaryotic and Eukaryotic RNA's differ in that:
Eukaryotes have a pre-mRNA that requires splicing to create the functional transcript.
In eukaryotes, the primary transcript is much longer than the mRNA that will eventually be translated. This can be explained by which of the following?
Introns have not yet been removed from the transcript.
The genetic code is redundant. What is meant by this statement?
More than one codon can specify the addition of the same amino acid.
The genetic code is composed of only four nucleotides. There are sixty-four total codons that can be made using four different nucleotides, however, there are only twenty different amino acids created by ribosomes. What is the reason for this discrepancy?
More than one codon sequence can code for the same amino acid.
How many strands of DNA are used as a template during the process of transcription?
One
How can RNA be distinguished from DNA?
RNA has a hydroxyl (-OH) group on the 2' carbon of the ribose sugar.
Which of the following processes occurs during transcription?
RNA is synthesized
During transcription, which enzyme catalyzes the addition of new ribonucleotides to the free 3' of the growing molecule?
RNA polymerase
Which of the following statements is true?
Ribosomes read mRNA from the 5' to the 3' end and synthesize the nascent protein chain from the amino to the carboxyl terminus
What single nucleotide substitution in the codon UAU for the amino acid tyrosine, Tyr, would produce a silent mutation?
UAC
Which point mutation would be most likely to have a catastrophic effect?
a base deletion near the start of the coding sequence
Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?
a deletion of two nucleotides
Which of the following occurs in the nucleus?
both transcription and replication of genetic material
A tRNA that carries a specific amino acid enters the protein-synthesizing machinery at the ribosomes and pairs with the appropriate:
codon
A random change in a DNA nucleotide base sequence:
constitutes a mutation.
An original section of DNA has the base sequence AGCGTTACCGT. A mutation in this DNA strand results in the base sequence AGGCGTTACCGT. What type of mutation does this change represent?
frameshift mutation
According to the central dogma, what is the intermediate molecule involved in the flow of information in a cell that should go in the blank?DNA → ________ → Proteins
mRNA
Which of the following molecular structures contain codons?
mRNA
Which part of the eukaryotic cell is the location of transcription?
nucleus
A gene, or transcription unit, contains
promoter, RNA-coding sequence, terminator
What is the site of protein synthesis?
ribosome
Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase?
several transcription factors
How does the primary transcript of a prokaryotic cell compare to the functional mRNA?
the primary transcript is the same size as the mRNA
Which of the following processes is the first event to take place in translation in eukaryotes?
the small subunit of the ribosome recognizes and attaches to the 5′ cap of mRNA
Which of the following processes occurs in prokaryotes but not in eukaryotes?
transcription and translation occur simultaneously
The process of copying genetic information from DNA to RNA is called:
transcription.
Which of the following "reads" codons?
transfer RNA
Which of the following has anticodons?
transfer RNA
The process of converting the "message" of mRNA into a sequence of amino acids is called:
translation
RNA splicing joins
two exon sequences
