AP Bio: Intro to Unit 6

1. What do you think "gene expression" means?

1. Why might cells need to control which genes are "turned on" or "turned off"?

What is the primary definition of gene expression?

• The process of a cell dividing into two daughter cells.

• The process by which a gene is used to create a functional product, often a protein.

• The process of DNA replication before cell division.

• The process of breaking down proteins into amino acids.

What example do they give about why not every gene should be expressed in every cell?

• A brain cell making heart proteins

• An eye cell making stomach acid

• A skin cell making bone material

• A muscle cell making nerve signals

3. In prokaryotes, transcription and translation:

• 3. Happen in separate compartments

• 3. Only happen during cell division

• 3. Require a nucleus

• 3. Can happen at the same time in the cytoplasm

How does the location of transcription and translation differ between prokaryotic and eukaryotic cells?

• In prokaryotes, both occur simultaneously in the cytoplasm; in eukaryotes, transcription is in the nucleus and translation in the cytoplasm.

• In prokaryotes, transcription occurs in the nucleus, and translation in the cytoplasm, similar to eukaryotes.

• Eukaryotes have no nucleus, so transcription and translation happen in the cytoplasm.

• Prokaryotes only perform transcription, not translation.

What is the main function of regulatory proteins, also known as transcription factors?

• To break down proteins into amino acids.

• To transport mRNA out of the nucleus.

• To decrease or increase the rate of transcription.

• To replicate DNA during cell division.

Environmental factors can influence gene expression by:

• Affecting transcription factors

• Stopping cell division

• Changing the DNA sequence

• Destroying the cell

3. The lac operon regulation makes sense because:

• 3. Bacteria can't digest lactose

• 3. Bacteria always need lactose enzymes

• 3. Lactose is toxic to bacteria

• 3. Bacteria only need lactose enzymes when lactose is present

In the Lac Operon, what event allows the genes to be expressed when lactose is present?

• The repressor protein binds more tightly to the operator, stopping transcription.

• Lactose binds to the repressor protein, causing it to detach from the operator and allow transcription.

• The promoter region is removed, preventing RNA polymerase from binding.

• The genes in the operon are permanently turned off.