AP Biology Molecular Biology

What is the function of reverse transcriptase in retroviruses?

• It hydrolyzes the host cell's DNA.

• It uses viral RNA as a template for DNA synthesis

• It converts host cell RNA into viral DNA.

• It translates viral RNA into proteins.

A biochemist isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture?

• DNA ligase
• nucleotides
• DNA polymerase III
• Okazaki fragments

At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork:
3' C C T A G G C T G C A A T C C 5'
An RNA primer is formed starting at the red T of the template. Which of the following represents the primer sequence?

• 5' G C C T A G G 3'
• 5' A C G U U A G G 3'
• 5' A C G T T A G G 3'
• 3' G C C T A G G 5'

Which of the following help(s) to hold the DNA strands apart while they are being replicated?

• RNA primase
• single–strand binding proteins
• DNA polymerase I
• DNA ligase

Which enzyme catalyzes the elongation of a DNA strand in the 5' ---> 3' direction?

• DNA polymerase I
• DNA polymerase III
• helicase
• topoisomerase

What is meant by the description "antiparallel" regarding the strands that make up DNA?

• The twisting nature of DNA creates nonparallel strands.
• One strand is positively charged and the other is negatively charged.
• The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
• Base pairings create unequal spacing between the two DNA strands

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

• Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many.
• Prokaryotic chromosomes have histones, whereas eukaryotic chromosomes do not.
• The rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes.
• Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not.

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?

• The same codons in different organisms translate into the different amino acids.
• A gene from an organism can theoretically be expressed by any other organism.
• All organisms have experienced convergent evolution.
• DNA was the first genetic material.

Tags

NGSS.HS-LS1-1

Which of the following provides some evidence that RNA probably evolved before DNA?

• RNA polymerase uses DNA as a template.
• DNA polymerase III does not require localized unwinding of the DNA.
• DNA polymerase III uses primer, usually made of RNA.
• RNA polymerase makes a single–stranded molecule.

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?

• It catalyzes the lengthening of telomeres.
• It synthesizes RNA nucleotides to make a primer.
• It unwinds the parental double helix.
• It joins Okazaki fragments together.