AP Biology: Unit 5 Review

Which of the following is true of DNA Replication?

• DNA is semi conservative because it creates two new strands of old nucleotide.

• New DNA strands are being synthesized in the 5' to 3' direction

• DNA is being synthesized in the 3' to 5' directions from a template strand

• RNA is being synthesized by RNA polymerase in the 5' to 3' direction

• A sense strand is created from a nonsense strand of DNA using RNA polymerase

Where does RNA polymerase bind to DNA?

• at an activator site

• on the coding gene sequence

• at a promoter region

• downstream of the coding sequence

• Where the RNA primer is placed

Which of the following occur during RNA processing? (more than 1 answer applies)

• exons can be removed

• spliceosomes remove introns

• a poly-A tail and GTP cap are added

• DNA helicase unzips DNA

• activator sequences initiate transcription

Which of the following is a similarity between the process prokaryotic and eukaryotic organisms implement for protein synthesis?

• Transcription takes place in the nucleus, translation takes place in the cytoplasm

• Introns are removed by spliceosomes

• RNA processing adds a cap and tail to the mature RNA strand

• Transcription and translation happen simultaneously

• Ribosomes for phosphodiester bonds between amino acids

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NGSS.HS-LS1-1

Bacterial cells that contain pGal will fluoresce blue under ultraviolet light. Which of the following is the most likely outcome of replacing the lacA gene in the E. coli lac operon with the gene encoding pGal?

• When lacY and lac Z are breaking down and transporting lactose, the bacteria will fluoresce blue under ultraviolet light

• lacZ will only produce the enzyme for breaking down galactose in the presence of ultraviolet light

• the repressor enzyme will only be able to bind to the operator under the presence of lactose

• When the regulatory gene is stimulated by lactose, it will cause the gene to fluoresce blue

• All structural genes downstream from the placement of lacA will be inhibited due to this substitution mutation.

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NGSS.HS-LS1-1

Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism.

Approximately what percentage of the nucleotides in this sample will be thymine?

• 12%

• 24%

• 31%

• 38%

Replication in prokaryotes differs from replication in eukaryotes for which of these reasons?

• Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many.

• Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not.

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent

• leading strands and Okazaki fragments

• lagging strands and Okazaki fragments.

Which of the following covalently connects segments of DNA?

• helicase

• DNA polymerase

• ligase

Which of the following synthesizes short segments of RNA?

• helicase

• DNA polymerase

• primase