Chapter 17 MB

Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression? a. A cap is added to the 5' end of the mRNA. b. RNA polymerase binds to the promoter. c. mRNA, tRNA, and rRNA are transcribed. d. RNA polymerase requires a primer to elongate the molecule.

a. A cap is added to the 5' end of the mRNA.

Which one of the following, if missing, would usually prevent translation from starting? a. AUG codon b. exon c. poly-A tail d. 5' cap

a. AUG codon

Where does RNA polymerase begin transcribing a gene into mRNA? a. It starts after a certain nucleotide sequence called a promoter. b. It starts at one end of the chromosome. c. It looks for the AUG start codon. d. The ribosome directs it to the correct portion of the DNA molecule. e. Transfer RNA acts to translate the message to RNA polymerase.

a. It starts after a certain nucleotide sequence called a promoter.

Once researchers identified DNA as the unit of inheritance, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. What is the mechanism of information transfer in eukarotes? a. Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place. b. Proteins transfer information from the nucleus to the ribosome, where protein synthesis takes place. c. DNA from a single gene is replicated and transferred to the cytoplasm, where it serves as a template for protein synthesis. d. Transfer RNA takes information from DNA directly to a ribosome, where protein synthesis takes place.

a. Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place.

What does it mean when we say the genetic code is redundant? a. More than one codon can specify the addition of the same amino acid. b. The genetic code is different for different domains of organisms. c. The genetic code is universal (the same for all organisms). d. A single codon can specify the addition of more than one amino acid.

a. More than one codon can specify the addition of the same amino acid.

What name is given to the process in which pre-mRNA is edited into mRNA? a. RNA processing b. gene expression c. polypeptide formation d. transcription e. translation

a. RNA processing

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is _____. a. 5' TCA 3' b. 3' UCA 5' c. 3' ACU 5' d. 3' UGA 5'

b. 3' UCA 5'

The direction of synthesis of an RNA transcript is _____. a. 1' —> 5' b. 5' —> 3' c. 1' —> 3' d. 3' —> 5' e. 2' —> 4'

b. 5' —> 3'

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following? a. DNA was the first genetic material. b. A gene from an organism can theoretically be expressed by any other organism. c. The same codons in different organisms translate into different amino acids. d. Different organisms have different types of amino acids.

b. A gene from an organism can theoretically be expressed by any other organism.

What determines which base is to be added to an RNA strand during transcription? a. The order of the chemical groups in the backbone of the RNA molecule b. Base pairing between the DNA template strand and the RNA nucleotides c. The previous base d. Base pairing between the two DNA strands

b. Base pairing between the DNA template strand and the RNA nucleotides

DNA does not store the information to synthesize which of the following? a. Proteins b. Organelles c. DNA d. Messenger RNA

b. Organelles

In the process of transcription, _____. a. mRNA attaches to ribosomes b. RNA is synthesized c. DNA is replicated d. proteins are synthesized

b. RNA is synthesized

The flow of information in a cell proceeds in what sequence? a. from DNA to protein to RNA b. from DNA to RNA to protein c. from RNA to DNA to protein d. from RNA to protein to DNA e. from protein to RNA to DNA

b. from DNA to RNA to protein

Codons are part of the molecular structure of _____. a. a protein b. mRNA c. tRNA d. rRNA

b. mRNA

Which of the following specifies a single amino acid in a polypeptide chain? a. the aminoacyl-tRNA synthetase b. the three-base sequence of mRNA c. the complementarity of DNA and RNA d. the base sequence of the tRNA

b. the three-base sequence of mRNA

How does termination of translation take place? a. The end of the mRNA molecule is reached. b. The poly-A tail is reached. c. A stop codon is reached. d. The 5' cap is reached.

c. A stop codon is reached.

Codons are three-base sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare? a. The translation of codons is mediated by tRNAs in eukaryotes, but translation requires no intermediate molecules such as tRNAs in prokaryotes. b. Prokaryotic codons usually specify different amino acids than those of eukaryotes. c. Codons are a nearly universal language among all organisms. d. Prokaryotic codons usually contain different bases than those of eukaryotes.

c. Codons are a nearly universal language among all organisms.

What is the process called that converts the genetic information stored in DNA to an RNA copy? a. Replication b. Translation c. Transcription d. Translocation

c. Transcription

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is _____. a. UUA b. AAA c. UUU d. TTT

c. UUU

Which of the following occurs in prokaryotes but not in eukaryotes? a. post-transcriptional splicing b. translation in the absence of a ribosome c. concurrent transcription and translation d. gene regulation

c. concurrent transcription and translation

According to the central dogma, what molecule should go in the blank? DNA → _____ → Proteins a. tRNA b. mtDNA c. mRNA d. rRNA

c. mRNA

Translation requires _____. a. mRNA, tRNA, and DNA b. mRNA, DNA, and rRNA c. mRNA, tRNA, and rRNA d. mRNA, tRNA, DNA, and rRNA

c. mRNA, tRNA, and rRNA

Transcription begins at a promoter. What is a promoter? a. Part of the RNA molecule itself b. The same as a start codon c. A site found on the RNA polymerase d. A site in DNA that recruits the RNA Polymerase

d. A site in DNA that recruits the RNA Polymerase

Which of the following terms best describes the relationship between the newly synthesized RNA molecule and the DNA template strand? a. Permanently base-paired b. Identical c. Covalently bound d. Complementary

d. Complementary

What happens to RNA polymerase II after it has completed transcription of a gene? a. It joins with another RNA polymerase to carry out transcription. b. It is degraded. c. It begins transcribing the next gene on the chromosome. d. It is free to bind to another promoter and begin transcription.

d. It is free to bind to another promoter and begin transcription.

Which of the following statements best describes the promoter of a protein-coding gene? a. The promoter is a site found on RNA polymerase. b. The promoter is part of the RNA molecule itself. c. The promoter is a site at which only RNA polymerase will bind. d. The promoter is a nontranscribed region of a gene.

d. The promoter is a nontranscribed region of a gene.

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. a substitution of the third nucleotide in an ACC codon b. a deletion of a codon c. a substitution of the first nucleotide of a GGG codon d. a deletion of two nucleotides

d. a deletion of two nucleotides

Alternative RNA splicing _____. a. can allow the production of similar proteins from different RNAs b. is a mechanism for increasing the rate of translation c. increases the rate of transcription d. can allow the production of proteins of different sizes and functions from a single gene

d. can allow the production of proteins of different sizes and functions from a single gene

A primary transcript in the nucleus of a eukaryotic cell is _____ the functional mRNA, while a primary transcript in a prokaryotic cell is _____ the functional mRNA. a. the same size as; larger than b. larger than; smaller than c. the same size as; smaller than d. larger than; the same size as

d. larger than; the same size as

RNA processing converts the RNA transcript into _____. a. a protein b. DNA c. a eukaryotic cell d. mRNA e. a polypeptide

d. mRNA

What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA? a. RNA processing b. gene expression c. polypeptide formation d. transcription e. translation

d. transcription

How is translation initiated? 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. All of the above.

Polypeptides are assembled from _____. a. hexoses b. glycerol c. nucleotides d. proteins e. amino acids

e. amino acids

After an RNA molecule is transcribed from a eukaryotic gene, what are removed and what are spliced together to produce an mRNA molecule with a continuous coding sequence? a. operators ... promoters b. silencers ... enhancers c. exons ... introns d. promoters ... operators e. introns ... exon

e. introns ... exon

A codon consists of _____ bases and specifies which _____ will be inserted into the polypeptide chain. a. four ... amino acid b. three ... nucleotide c. two ... nucleotide d. four ... fatty acid e. three ... amino acid

e. three ... amino acid

What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein? a. RNA processing b. gene expression c. polypeptide formation d. transcription e. translation

e. translation

Which one of the following is true of tRNAs? a. tRNAs carry special sequences known as codons. b. tRNAs are double-stranded. c. There are four types of tRNA. d. Each tRNA binds a particular codon. e. All of the above. f. None of the above.

f. None of the above.