AP Biology Unit 6 Biotechnology

Which enzyme catalyzes the elongation of a DNA strand in the 5ʹ → 3ʹ direction?

• primase

• DNA ligase

• DNA Polymerase

• helicase

A new DNA strand elongates only in the 5ʹ to 3ʹ direction because

• DNA polymerase can only add nucleotides to the free 3ʹ end

• Okazaki fragments prevent elongation in the 3ʹ to 5ʹ direction.

In which of the following actions does RNA polymerase differ from DNA polymerase?

• RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis.

• RNA polymerase binds to single-stranded DNA, and DNA polymerase binds to double-stranded DNA.

What is the enzymatic function of restriction enzymes?

• to cleave nucleic acids at specific sites

• to add new nucleotides to the growing strand of DNA

During gel electrophoresis, the _______ pieces of DNA move farthest down the gel

• Smallest

• Biggest

What is the most useful change biotechnology has made in agriculture?

• Crops need more water

• Crops need more nutrients

• Crops need more time to grow

• Crops resist more diseases

Which of the following separates molecules by movement due to size and electrical charge?

• gel electrophoresis

• gene cloning

Restriction fragments of DNA are typically separated from one another by which process?

• gel electrophoresis

• PCR

The segment of DNA shown in the figure has restriction sites I and II, which create restriction fragments A, B, and C. Which of the gels produced by electrophoresis shown below best represents the separation and identity of these fragments?

• 
• 

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