Intro to Ch 17.

Multiple Choice

Why is gene expression considered a crucial process in the flow of genetic information within an organism?

• Because it allows DNA to replicate itself

• Because it directs the synthesis of proteins, linking genotype to phenotype

• Because it determines the cell's shape

• Because it prevents mutations

Multiple Choice

Which experiment provided support for the one gene–one enzyme hypothesis?

• Beadle and Tatum's experiment with bread mold exposed to X-rays

• Srb and Horowitz's experiment with arginine-deficient mutants

• The experiment with minimal medium and nutritional mutants

• The experiment with wild-type cells on minimal medium

Open Ended

Describe the process used to identify nutritional mutants in Neurospora, as shown in the diagram.

Multiple Choice

Which of the following statements about transcription and translation is correct?

• Transcription produces polypeptides directly from DNA

• Translation synthesizes RNA using information in DNA

• Transcription produces messenger RNA (mRNA)

• Ribosomes are the sites of transcription

Multiple Select

Select all features that distinguish transcription and translation in prokaryotic cells from eukaryotic cells.

• Translation can begin before transcription is finished in prokaryotes

• The nuclear envelope separates transcription from translation in eukaryotes

• RNA processing occurs in prokaryotes

• Eukaryotic RNA transcripts are modified through RNA processing

Open Ended

Compare the processes of transcription and translation in bacterial and eukaryotic cells based on the diagram.

Multiple Choice

What is the central dogma of molecular biology?

• DNA → RNA → protein

• Protein → RNA → DNA

• RNA → DNA → protein

• Protein → DNA → RNA

Open Ended

How are the instructions for assembling amino acids into proteins encoded into DNA?

Multiple Select

Which statements about the triplet code and its role in gene expression are correct?

• The triplet code consists of three-nucleotide words.

• Each triplet codes for a single amino acid.

• Triplet code words are overlapping.

• Triplet code words are transcribed into mRNA.

Open Ended

What determines which DNA strand is used as the template for transcription in a given gene?

Multiple Choice

How many codons code for amino acids, and how many serve as stop signals in the genetic code?

• 61 code for amino acids, 3 are stop signals

• 64 code for amino acids, 0 are stop signals

• 60 code for amino acids, 4 are stop signals

• 63 code for amino acids, 1 is a stop signal

Multiple Choice

Which codon serves as both a start signal and codes for methionine in the genetic code?

• AUG

• UAA

• UGA

• UAG

Open Ended

Explain the significance of the genetic code being nearly universal among different organisms.

Multiple Select

Which of the following statements about RNA polymerase is correct? Select all that apply.

• RNA polymerase catalyzes RNA synthesis.

• RNA polymerase needs a primer to start synthesis.

• RNA polymerase joins RNA nucleotides together.

• RNA polymerase follows the same base-pairing rules as DNA except uracil substitutes for thymine.

Open Ended

Describe the process of transcription, including the roles of the promoter, terminator, and transcription unit.

Multiple Choice

Which of the following is NOT one of the three stages of transcription?

• Initiation

• Elongation

• Replication

• Termination

Open Ended

Explain the role of transcription factors and the TATA box in the initiation of transcription in eukaryotes.

Multiple Select

Select all statements that correctly describe the termination of transcription in bacteria and eukaryotes.

• In bacteria, the polymerase stops transcription at the end of the terminator.

• In eukaryotes, RNA polymerase II transcribes the polyadenylation signal sequence.

• In bacteria, RNA polymerase II transcribes the polyadenylation signal sequence.

• In eukaryotes, the mRNA can be translated without further modification.

Multiple Choice

Which of the following is a function shared by both the 5' cap and the poly-A tail modifications of mRNA?

• Facilitate export of mRNA to the cytoplasm

• Initiate DNA replication

• Increase mutation rate

• Help ribosomes attach to the 3' end

Open Ended

How was the fundamental relationship between genes and proteins discovered?

Multiple Choice

What are the two stages involved in gene expression, the process by which DNA directs protein synthesis?

• Replication and transcription

• Transcription and translation

• Translation and replication

• Transcription and duplication