Grade 12 Biology Quiz

What is the function of helicase in DNA replication?

• Catalyzes synthesis of new DNA

• Relieves strain by breaking, swiveling, and rejoining DNA strand

• Adds nucleotides to the 3' end of preexisting chain

• Untwists the DNA at replication forks

What is the role of DNA polymerase in the replication process?

• Untwists the DNA at replication forks

• Joins sugar-phosphate backbones of Okazaki fragments

• Relieves strain by breaking, swiveling, and rejoining DNA strand

• Catalyzes synthesis of new DNA by adding nucleotides to 3' end of preexisting chain

Which scientist discovered that the transforming agent in bacteria was DNA?

• Hershey and Chase

• Oswald Avery

• Frederick Griffith

• Edwin Chargaff

What is the function of tRNA in translation?

• Catalyzes the process of removing introns and joining exons

• Produces different combination of exons

• Site of protein synthesis

• Transfers specific amino acids to ribosomes based on anticodon to mRNA codon

What is the result of a frameshift mutation in mRNA?

• Different amino acid

• No effect

• Stop codon not an amino acid

• mRNA read incorrectly, nonfunctional protein

What is the function of a repressor in the operon system?

• Binds to enhancer regions and other proteins

• Decreases transcription

• Increases transcription

• Binds to specific AA

What is the purpose of DNA methylation?

• Produces different combination of exons

• Catalyzes the process of removing introns and joining exons

• Tightly packs DNA for transcription

• Loosens DNA for transcription

What is the role of morphogens in pattern formation?

• Establish embryo's axes

• Control pattern formation

• Trigger cell to differentiate

• Programmed cell death

What is the function of the P53 gene?

• Halts cell cycle for DNA repair

• Causes programmed cell death

• Inhibits cell division

• Stimulates cell division

What is the result of an active oncogene and loss of tumor suppressor gene?

• No effect

• Inhibits cell division

• Stimulates cell cycle

• Causes cancer