AP Bio Practice Quiz

Example Questions From the Test

• 1Why is substantially less chemical energy generally available to organisms at higher trophic levels?
  • Organisms use much of the energy they acquire for metabolism, and energy is dissipated as heat.
  • Consumers destroy energy when they digest organic molecules.
  • Producers store no chemical energy after completing photosynthesis.
  • Energy cycles completely back to producers after each feeding interaction.
• 2In an E. coli cell, lactose is available and glucose is scarce. What is expected for the lac operon?
  • Transcription remains off because lactose binds directly to RNA polymerase.
  • Transcription is low because glucose scarcity activates the lac repressor.
  • Transcription is high because the repressor is inactivated and CAP activation is favored.
  • The structural genes are permanently removed from the bacterial chromosome.
• 12Why is a short RNA primer needed during DNA replication?
  • Ligase uses the primer to separate the two parental strands.
  • Helicase recognizes RNA but cannot recognize DNA.
  • DNA polymerase can add nucleotides only to an existing 3′ end.
  • RNA nucleotides prevent mutations in newly synthesized DNA.