AP Biology Unit 6: Gene Expression & Regulation

What is the role of transcription factors in gene regulation?

• Transcription factors are enzymes that synthesize RNA from DNA.

• Transcription factors are proteins that bind to specific DNA sequences to regulate the transcription of genes, either promoting or inhibiting RNA polymerase activity.

• Transcription factors are molecules that transport RNA out of the nucleus.

• Transcription factors are lipids that modify DNA structure.

What direction are new DNA strands synthesized during replication?

• 5' to 3' direction

• 3' to 5' direction

• Left to Right direction

• Right to Left direction

What is the significance of the semi-conservative nature of DNA replication?

• It allows for the complete destruction of old DNA strands.

• It ensures that each new DNA molecule consists of one old strand and one newly synthesized strand, ensuring genetic continuity.

• It prevents mutations from occurring during DNA replication.

• It enables the rapid duplication of DNA without any errors.

What is the structure of the DNA double helix?

• The DNA double helix is a single strand of nucleotides.

• The DNA double helix has a uniform diameter because purines (A, G) pair with pyrimidines (C, T), maintaining consistent spacing.

• The DNA double helix is composed of only purines.

• The DNA double helix is a flat structure without any twists.

How does DNA polymerase differ from RNA polymerase in terms of initiation?

• DNA polymerase can initiate DNA synthesis on its own, while RNA polymerase requires a primer.

• Both DNA polymerase and RNA polymerase require a primer to initiate synthesis.

• DNA polymerase requires a primer to initiate DNA synthesis, while RNA polymerase can initiate RNA synthesis on its own.

• RNA polymerase can only synthesize RNA in the presence of a primer, while DNA polymerase does not need one.

What determines the nucleotide sequence of a newly synthesized DNA strand?

• The nucleotide sequence of the newly synthesized strand itself.

• The nucleotide sequence of the template strand.

• The presence of RNA primers during replication.

• The concentration of nucleotides in the cell.

How do mutations affect gene expression?

• Mutations can lead to changes in the protein produced, affecting gene expression and function.

• Mutations have no effect on gene expression.

• Mutations only affect the physical appearance of an organism.

• Mutations can only occur in non-coding regions of DNA.

What is the process of transcription?

• Transcription is the process of synthesizing RNA from a DNA template, where RNA polymerase binds to the promoter region of a gene.

• Transcription is the process of converting RNA into DNA using reverse transcriptase.

• Transcription is the process of synthesizing proteins from RNA templates in the ribosome.

• Transcription is the process of replicating DNA to produce identical copies.

What is the role of RNA polymerase in transcription?

• RNA polymerase synthesizes RNA by binding to a DNA template and initiating RNA synthesis without the need for a primer.

• RNA polymerase translates mRNA into proteins during translation.

• RNA polymerase repairs damaged DNA strands during replication.

• RNA polymerase acts as a catalyst for the breakdown of RNA molecules.

What is the difference between a sense strand and a nonsense strand of DNA?

• The sense strand is the coding strand that has the same sequence as the mRNA (except for T instead of U), while the nonsense strand is the template strand used for transcription.

• The sense strand is the template strand used for transcription, while the nonsense strand is the coding strand that has the same sequence as the mRNA.

• The sense strand is involved in DNA replication, while the nonsense strand is involved in protein synthesis.

• The sense strand contains only non-coding regions, while the nonsense strand contains coding regions.