Review Questions

Review Questions

What is the flow of information for the synthesis of proteins according to the central dogma?
  1. DNA to mRNA to protein
  2. DNA to mRNA to tRNA to protein
  3. DNA to protein to mRNA to protein
  4. mRNA to DNA to mRNA to protein
The DNA of virus A is inserted into the protein coat of virus B. The combination virus is used to infect E. coli. The virus particles produced by the infection are analyzed for DNA and protein. What results would you expect?
  1. DNA and protein from B
  2. DNA and protein from A
  3. DNA from A and protein from B
  4. DNA from B and protein from A

The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code explains this?

  1. complementarity
  2. degeneracy
  3. nonsense codons
  4. universality
How many nucleotides are in 12 mRNA codons?
  1. 12
  2. 24
  3. 36
  4. 48

Which of the following molecules does not contain genetic information?

  1. DNA
  2. mRNA
  3. protein
  4. RNA

Which molecule in the central dogma can be compared to a disposable photocopy of a book kept on reserve in the library?

  1. DNA
  2. mRNA
  3. protein
  4. tRNA

Which subunit of the E. coli polymerase confers specificity to transcription?

  1. α
  2. β
  3. β′
  4. σ

Why are the −10 and −35 regions of prokaryotic promoters called consensus sequences?

  1. They are identical in all bacterial species.
  2. They are similar in all bacterial species.
  3. They exist in all organisms.
  4. They have the same function in all organisms.

The sequence that signals the end of transcription is called the ________.

  1. promoter.=
  2. stop codon.=
  3. TATA box.=
  4. terminator.=
If the ρ protein is missing, will a prokaryotic gene be terminated?
  1. It depends on the gene.
  2. No, the rho protein is essential.
  3. Transcription termination is not required.
  4. Yes, the rho protein is not involved in transcription.
Which feature of promoters can be found in both prokaryotes and eukaryotes?
  1. GC box
  2. octamer box
  3. TATA box
  4. -10 and -35 sequences
At what stage in the transcription of a eukaryotic gene would TFII factors be active?
  1. elongation
  2. initiation
  3. processing
  4. termination
Which polymerase is responsible for the synthesis of 5S rRNA?
  1. polymerase I
  2. polymerase II
  3. polymerase III
  4. ribonuclease I

What transcripts will be most affected by low levels of α-amanitin?

  1. 18S and 28S rRNAs
  2. 5S rRNAs and tRNAs
  3. other small nuclear RNAs
  4. pre-mRNAs
Which of the following features distinguishes eukaryotic transcription from bacterial transcription?
  1. Eukaryotic transcription does not start at a consensus sequence.
  2. Eukaryotic transcription does not require an initiation complex.
  3. Eukaryotic transcription and translation do not take place at the same time.
  4. Eukaryotic transcription does not require a termination sequence.

A poly-A sequence is added at the:

  1. 5′ end of a transcript in the nucleus
  2. 3′-end of a transcript in the nucleus
  3. 5′ end of a transcript in the cytoplasm
  4. 3′-end of a transcript in the cytoplasm
Which pre-mRNA processing step is important for initiating translation?
  1. poly-A tail
  2. RNA editing
  3. splicing
  4. 7-methylguanosine cap
Where are the RNA components of ribosomes synthesized?
  1. cytoplasm
  2. endoplasmic reticulum
  3. nucleus
  4. nucleolus
What processing step enhances the stability of pre-tRNAs and pre-rRNAs?
  1. cleavage
  2. methylation
  3. nucleotide modification
  4. splicing
What are introns?
  1. DNA sequences to which polymerases bind
  2. the processed mRNA
  3. translated DNA sequences in a gene
  4. untranslated DNA sequences in a gene
What is often the first amino acid added to a polypeptide chain?
  1. adenine
  2. leucine
  3. methionine
  4. thymine

In any given species, there are at least how many types of aminoacyl tRNA synthetases?

  1. 20
  2. 40
  3. 100
  4. 200

In prokaryotic cells, ribosomes are found in/on the ________.

  1. cytoplasm
  2. mitochondrion
  3. nucleus
  4. endoplasmic reticulum

The peptide bond synthesis in prokaryotic translation is catalyzed by ________.

  1. a ribosomal protein
  2. a cytoplasmic protein
  3. mRNA itself
  4. ribosomal RNA

What would happen if the 5′-methyl guanosine was not added to an mRNA?

  1. The transcript would degrade when the mRNA moves out of the nucleus to the cytoplasm.
  2. The mRNA molecule would stabilize and start the process of translation within the nucleus of the cell.
  3. The mRNA molecule would move out of the nucleus and create more copies of the mRNA molecule.
  4. The mRNA molecule would not be able to add the poly-A tail on its strand at the 5′ end.

Which of the following is associated with the docking of mRNA on a ribosome in eukaryotic cells?

  1. Kozak’s rules
  2. poly-A sequence
  3. Shine-Dalgarno sequence
  4. TATA box