Bio Ch 17

Which of the following terms best describes the relationship between the newly synthesized RNA molecule and the DNA template strand?

Complementary

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

attachment of amino acids to tRNAs

Use the scheme to answer the question. I −→−−−−enzymeX→enzymeX II −→−−−−enzymeY→enzymeY III −→−−−−enzymeZ→enzymeZ IV Refer to the metabolic pathway illustrated. If I, II, III and IV are all required for growth, a bacterial strain that does not make enzyme Y would be able to grow on medium supplemented with which of the following compounds?

nutrients A and C only

In eukaryotic cells, transcription cannot begin until

several transcription factors have bound to the promoter. Submit

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

simultaneous transcription and translation of the same mRNA

Which of the following statements about ribozymes is/are correct? Select all that apply.

In some genes, intron RNA functions as a ribozyme and catalyzes its own excision. A ribosome can be regarded as one large ribozyme. Ribozymes are RNA molecules that function as enzymes.

Which of the following is true of a codon?

It can be either in DNADNA or in RNARNA.

Which of the following statements about the function of RNA polymerase is correct?

It unwinds the double helix and adds nucleotides to a growing strand of RNA.

Use the scheme to answer the question. I −→−−−−enzymeX→enzymeX II −→−−−−enzymeY→enzymeY III 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.

Transcription begins at a promoter. What is a promoter?

A site in DNA that recruits the RNA Polymerase

Which of the following mutations would likely be most dangerous to a cell?

Deletion of one nucleotide Submit

Which of the following best describes the redundancy in the genetic code?

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

DNA does not store the information to synthesize which of the following?

Organelles

Which answer correctly compares prokaryotic and eukaryotic codons?

Organisms utilize codons that are nearly universal among all organisms.

Which of the following statements is true about protein synthesis in prokaryotes?

Translation can begin while transcription is still in progress. Submit

What does a mutagen cause?

a change in the sequence of DNA

Which of these is currently considered the best definition of a gene?

a gene codes for either a polypeptide or an RNA molecule

The anticodon of a particular tRNAtRNA molecule is

complementary to the corresponding mRNAmRNA codon.

If a bacteria contained a mutant aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA which of the following would occur?

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

Which of the following is most likely to occur if a researcher removes the 5' cap and poly-A tail of an mRNA and inserts the mRNA molecule into a eukaryotic cell?

The molecule will be degraded by enzymes.

Use the scheme to answer the question. I −→−−−−enzymeX→enzymeX II −→−−−−enzymeY→enzymeY III −→−−−−enzymeZ→enzymeZ IV Refer to the metabolic pathway illustrated. If I, II, III, and IV are all required for growth, a bacterial strain that does not make enzyme X would be able to grow on medium supplemented with which of the following nutrient(s)?

nutrients I and II only

Which component is directly involved in translation?

ribosome

Where does RNA polymerase begin transcribing a gene into mRNA?

it starts after a certain nucleotide sequence called a promoter

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

A codon consists of __________ bases and specifies which __________ will be inserted into the polypeptide chain.

three, amino acid

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

transcription factors

How is translation initiated?

All of the listed answers are correct. Submit

What determines which base is to be added to an RNA strand during transcription?

Base pairing between the DNA template strand and the RNA nucleotides

A particular triplet of bases in the template strand of DNA is 5'-AAA-3'. The anticodon on the tRNA that binds the mRNA codon is ________.

3'-AAA-5'

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'

Use this model of a eukaryotic primary transcript to answer the following question.E = exon and I = intron5'-UTR E1 I1 E2 I2 E3 I3 E4 UTR-3'If the primary transcript is processed and transported to the cytosol, which of the following molecules best represents the mRNA that will be produced?

5'-UTR E1 E2 E3 E4 UTR-3'

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

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

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.

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.

What happens to RNA polymerase II after it has completed transcription of a gene?

It is free to bind to another promoter and begin transcription.

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.

Which of the following molecules are produced by transcription? Select all that apply.

Messenger RNA Ribozymes

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 that accomplishes this task in eukaryotes?

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

The average length of a transcription unit along a eukaryotic DNA molecule is about 27,000 nucleotide pairs, whereas an averaged-sized protein is about 400 amino acids long. What is the best explanation for this fact?

Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that are not translated.

Which one of the following statements is true of tRNAs?

None of the listed answers are correct.

Which of the following is true of RNARNA processing?

Nucleotides are added at both ends of the RNARNA.

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. Submit

Which of the following processes occurs as part of transcription?

RNA is synthesized

Which of the following molecules is/are produced by translation? Include molecules that are subject to further modification after initial synthesis. Select all that apply.

RNA polymerase Aminoacyl-tRNA synthetase

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

RNA polymerase II

Which of the following statements about RNA processing is correct?

Ribozymes may function in RNA splicing.

Which of the following statements best describes the promoter of a protein-coding gene?

The promoter is a nontranscribed region of a gene

Which of the following best explains the observation that in bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs?

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

What is the process called that converts the genetic information stored in DNA to an RNA copy?

Transcription

What is a ribozyme?

a biological catalyst made of RNA

Which of the following mutations would be most likely to have a harmful effect on an organism?

a single nucleotide insertion downstream of, and close to, the start of the coding sequence

The flow of information in a cell proceeds in what sequence?

from DNA to RNA to protein

According to the central dogma, which of the following intermediate molecules correctly completes the flow chart describing the flow of information in a cell blank?

mRNA

Which of the following molecular structures contains codons?

mRNA

Which answer correctly compares the primary transcript in the nucleus of a eukaryotic cell with the functional mRNA?

the primary transcript is larger than the mRNA

Which answer correctly compares the primary transcript in a prokaryotic cell with the functional mRNA?

the primary transcript is the same size as the mRNA

In the structure of many eukaryotic genes, individual exons parallel which of the following?

the various domains of the protein product