Biology Quiz

Which of the following is NOT true about gene expression in eukaryotes?

• Genes are never simultaneously transcribed and translated.

• Both Eukaryotes and bacteria have rRNA and tRNA genes.

• The lac mRNA in bacteria encodes multiple proteins.

• There is only one definition of a gene.

What was the primary finding of the experiment performed by George Beadle and Edward Tatum?

• A gene mutation can affect a single enzyme in the pathway for synthesis of arginine.

• A gene mutation in a single gene can affect multiple enzymes.

• Arginine is an essential amino acid for Neurospora.

• Auxotrophs cannot grow without supplementation of the amino acid they are missing.

In bacteria, where are RNAs primarily transcribed?

• Cytoplasm

• Rough ER

• Ribosome

• Nucleus

Which enzyme has activity that is most similar to RNA Polymerase?

• Helicase

• DNA Polymerase

• Primase

• Exonuclease

Which of the following statements about transcription is NOT TRUE?

• Transcription is a process that occurs in all living cells.

• Transcription results in the synthesis of RNA from a DNA template.

• Transcription occurs in the nucleus of eukaryotic cells.

• Transcription does not involve the unwinding of the DNA double helix.

In the absence of lactose, what happens to the expression of the lac repressor?

• It is not expressed

• It is expressed

• It is degraded

• It is mutated

Which of the following is true regarding the processing of mRNA in Eukaryotes but not in bacteria?

• Only Eukaryotes process their mRNAs through splicing, 5' capping, and poly-adenylation.

• Only Eukaryotes transcribe tRNAs, rRNAs, and mRNAs.

• Transcription and translation occur simultaneously in Eukaryotes, but not bacteria.

• Transcription and translation both occur in the nucleus in Eukaryotes.

What would be the effect of a mutation in the enzyme that adds the 5' guanosine cap to an mRNA?

• Drastically altering the polypeptide sequence of all proteins translated because deletion of one guanosine is a frameshift mutation.

• Increasing the amount of protein made from the mRNA because the 5' cap is no longer preventing the ribosome from binding.

• Decreasing the stability of all mRNAs, thereby decreasing the amount of protein produced by the cell.

• There would be no observable effect because the 5' cap is not translated into protein.

Which of the following best describes the nature of the genetic code as per the learning material?

• The genetic code is degenerate.

• The genetic code is completely overlapping.

• Each amino acid is encoded by a single base in DNA/RNA.

• The genetic code varies significantly between different organisms.

What is the most likely effect of a point mutation in the first base of a codon in a protein-coding gene?

• It is the least likely to disrupt the function of the protein.

• It is more likely to disrupt the function of the protein than a mutation in the third base.

• It has no effect on the protein function.

• It changes the protein into a completely different class of molecules.