Gene Expression-Unit Review

Which diagram shows a system in which the lac operon genes are about to be transcribed?

• Diagram B because the repressor protein is ready to transcribe the genes.
• Diagram A because the repressor protein is no longer attached to the DNA segment.
• Diagram B because there is no lactose present.
• Diagram A because the repressor protein is ready to transcribe the genes.

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NGSS.HS-LS1-1

Which of the following must happen for transcription of the lac operon genes to take place?

• The repressor protein binds to the DNA molecule, and RNA polymerase falls off.
• Lactose is removed from the system.
• The repressor protein falls off the DNA molecule, and RNA polymerase binds to the promoter.
• The repressor protein binds to the promoter sequence.

Which of the following clues would tell you if the lac operon is on?

• The cell membrane changes.
• RNA polymerase is blocked by the repressor.
• Lactose is absent.
• The repressor protein has fallen off the molecule.

How is the cell in Diagram B effectively using its resources?

• Since lactose is absent, the repressor protein is blocking the genes and stopping transcription.
• The cell continually produces the enzymes needed to break down lactose.
• RNA polymerase is transcribing the genes since lactose is present.
• Since lactose is present, the repressor protein will begin transcription.

How can a person's muscle cells have the same exact DNA sequences as their nerve cells even though the look and perform completely different?

• The two different cells become mutated
• The proteins expressed in each cell are different
• They actually have different DNA in the two types of cells.
• The genome of the different cells changes

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NGSS.HS-LS1-1

NGSS.HS-LS1-4

Why do bone cells become bone cells, heart cells become heart cells, skin cells become skin cells, etc...?

• It just happens randomly
• Determined by the mother while in the womb
• The turning on/off of certain genes that are needed for that type of cell
• The zygote tells them what to become

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NGSS.HS-LS1-4

When a human embryo is developing, the embryo produces a special type of hemoglobin not found in infant, child, or adult blood. Which of the following best explains how an embryo can produce a different type of hemoglobin from an infant, child, or adult?

• The embryo has different genes from the infant, child, or adult.
• Development and differentiation result in the loss of certain genes.
• Humans have genes for the different types of hemoglobin, which are expressed at different times.
• Aliens visited the human at different phases of their lives and changed them.

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NGSS.HS-LS1-4

NGSS.HS-LS3-2

Which of the following best explains the term gene expression?

• the production of proteins based on the genetic information in DNA
• the suppression of RNA polymerase
• the suppression of protein production
• the production of lipids based on the genetic information in DNA

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NGSS.HS-LS1-1

How is the information in a DNA molecule expressed in an organism?

• through plasmids
• through RNA polymerase
• through recombinant DNA
• through proteins

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NGSS.HS-LS1-1

What would happen if a chemical interfered with the ability of RNA polymerase to bind to a DNA molecule?

• Transcription would proceed, and a protein would be produced.
• The DNA molecule would replicate itself.
• The RNA polymerase would cut the DNA molecule in half.
• Transcription would not take place, and the protein would not be produced.