During the elongation phase of translation, which site in the ribosome represents the location where a codon is being read?

A site

Which of the following molecules are required for the process of translation?

mRNA, tRNA, and rRNA

Which of the following properties is associated with a protein that will be secreted from a eukaryotic cell?

Its signal sequence must target it to the ER, after which it goes to the Golgi.

Use the figure to answer the question.

The tRNA shown in the figure has its 3′ end projecting beyond its 5′ end. Which of the following processes will occur at this 3′ end?

The amino acid binds covalently.

Use the figure to answer the question.

The figure represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid?

5′-UUC-3′

Use the figure to answer the question.

What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure?

hydrogen bonding between base pairs

Use the following information to answer the question.

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5′-CCG-ACG-3′ (mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3′ to 5′ direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.

Which of the following anticodons in the first tRNA to bind will complement this mRNA?

3′-GGC-5′

Use the following information to answer the question.

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5′-CCG-ACG-3′ (mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3′ to 5′ direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.

Which of the following dipeptides will form from this mRNA?

proline-threonine

What is the function of the release factor during translation in eukaryotes?

It binds to the stop codon in the A site in place of a tRNA.

Which of the following statements correctly describes the function of a signal peptide?

It helps target a protein to the ER.

Which of the following processes is the first event to take place in translation in eukaryotes?

the small subunit of the ribosome recognizes and attaches to the 5′ cap of mRNA

In bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. Which of the following statements explains this fact?

The rules for base pairing between the third base of a codon and tRNA are flexible.

What would be the consequence of a mutation in a bacterial cell that produces a defective aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA?

Proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU.

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the ________.

binding of the anticodon to the codon and the attachment of amino acids to tRNAs

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is ________.

AAA

How does the primary transcript in the nucleus of a prokaryotic cell compare to the functional mRNA?

the primary transcript is the same size as the mRNA

How does the primary transcript in the nucleus of a eukaryotic cell compare to the functional mRNA?

the primary transcript is larger than the mRNA

Which one of the following statements about RNA processing is correct?

Ribozymes may function in RNA splicing.

Use this model of a eukaryotic transcript to answer the following question.

E = exon and I = intron

5′-UTR E1 I1 E2 I2 E3 I3 E4 UTR-3′

Which components of the previous molecule will also be found in mRNA in the cytosol?

5′-UTR E1 E2 E3 E4 UTR-3′

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after she has removed its 5′ cap and poly-A tail. Which of the following processes would you expect her to find to have occurred?

The molecule is digested by enzymes because it is not protected at the 5′ end.

In the structural organization of many eukaryotic genes, individual exons may be related to which of the following?

the various domains of the polypeptide product

Which of the following processes correctly describes alternative RNA splicing?

It can allow the production of proteins of different sizes and functions from a single mRNA.

Which of the following statements correctly describes a ribozyme?

It is an RNA with catalytic activity.

Which of the following processes occurs in eukaryotic gene expression?

A cap is added to the 5′ end of the mRNA.

Which of the following statements best describes the significance of the TATA box in the promoters of eukaryotes?

It is the recognition site for the binding of a specific transcription factor.

Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase?

several transcription factors

In eukaryotes, there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein?

RNA polymerase II

Which of the following statements best describes the termination of transcription in prokaryotes?

RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.

Which of the following processes occurs in prokaryotes but not in eukaryotes?

transcription and translation occur simultaneously

Codons are three-base sequences in mRNA that specify the addition of a single amino acid to the growing protein chain during translation. How do eukaryotic codons and prokaryotic codons compare?

Codons are a nearly universal language among all organisms.

According to the central dogma, what is the intermediate molecule involved in the flow of information in a cell that should go in the blank?
DNA → ________ → Proteins

mRNA

Once researchers identified DNA as the molecule responsible for transmitting heritable traits, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. Which of the following statements correctly describes the mechanism of information transfer in eukaryotes that accomplishes this task?

Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place.

The genetic code is redundant. What is meant by this statement?

More than one codon can specify the addition of the same amino acid.

Which of the following molecular structures contain codons?

mRNA

Which of the following processes occurs during transcription?

RNA is synthesized

Which of the following characteristics is directly related to the coding of a single amino acid during the process of translation?

the three-base sequence of mRNA

Which of the following statements supports the one gene-one enzyme hypothesis?

A mutation in a single gene can result in a defective protein.

The following question refers to this table of codons.

Refer to the figure. Which of the triplets below is a possible anticodon for a tRNA that transports proline to a ribosome?

3′-GGC-5′

The following question refers to this table of codons.

What amino acid sequence will be generated, based on the following mRNA codon sequence?
5′-AUG-UCU-UCG-UUA-UCC-UUG-3′

Met-Ser-Ser-Leu-Ser-Leu

The following question refers to this table of codons.

Which of the following sequences of nucleotides are possible in the template strand of DNA that would code for the polypeptide sequence Phe-Leu-Ile-Val?

3′-AAA-GAA-TAA-CAA-5′

Use the figure to answer the question.

Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain mutant for the gene encoding enzyme B would be able to grow on medium supplemented with which of the following nutrient(s)?

nutrient C only

Use the figure to answer the question.

Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on medium supplemented with which of the following nutrient(s)?

either nutrient B or C

Use the figure to answer the question.

The figure shows a simple metabolic pathway. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?

2

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true?

A gene from an organism can theoretically be expressed by any other organism.

A particular triplet of bases in the template strand of DNA is 5′-AGT-3′. What would be the corresponding codon for the mRNA that is transcribed?

3′-UCA-5′

Which of the following statements correctly describes Archibald Garrod's hypothesis for how "inborn errors of metabolism" such as alkaptonuria occur?

Genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes.