AP Biology DNA Practice

How do the leading, and the lagging strands differ?

• The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction.

• The leading strand is synthesized at twice the rate of the lagging strand.

• The leading strand is synthesized in short fragments that are ultimately stitched together, whereas the lagging strand is synthesized continuously. 

• The leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5? end. 

Suppose a double-stranded DNA molecule was shown to have 15% adenine bases. What would be the expected percentage of guanine bases in that molecule?

• 15%

• 35%

• 85%

• Not enough information

Consider the replication bubble diagrammed at the right. Which letters represent leading strands? 

• W and X

• Y and Z

• W and Z

• X and Y

Which enzyme is not working correctly if new DNA bases are not added to the template strand?

• DNA Polymerase

• Topoisomerase

• Ligase

• Primase

Which is the primary purpose of using restriction enzymes before gel electrophoresis?

• It cuts the DNA strands in a set location for analysis.

• It restricts the number of base pairs that can be tested in a sample

• It makes the testing simpler by moving the strands into the gel faster

• It charges the DNA strands

What is the purpose of gel electrophoresis in DNA analysis?

• To separate DNA based on size

• To visualize DNA fragments

• To create a DNA profile

• To compare DNA sequences

A method used to rapidly make multiple copies of a specific segment of DNA.

• PCR (Polymerse Chain Reaction)

• Electrophoresis

• DNA Probe

This is the last step of PCR and it requires the temperature to increase to 72C for one minute. Here, complementary strands will be produced from the corresponding base pairs, reforming the DNA into two new strands.

• Elongation by DNA Polymerase

• Primer Annealing

• Denaturation

Which is the primary purpose of using restriction enzymes in gel electrophoresis?

• It allows the strands of DNA to be cut into various lengths for testing

• It restricts the number of base pairs that can be tested in a sample

• It makes the testing simpler by moving the strands into the gel faster

• It charges the DNA strands

Which part(s) of a hair can be analyzed for DNA?

• root

• cuticle

• medulla

• cortex