Biology chapter 17 questions

Which of the following statements correctly describes a ribozyme?

It is an RNA with catalytic activity.

In eukaryotic cells, transcription cannot begin until

several transcription factors have bound to the promoter.

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

simultaneous transcription and translation of the same mRNA

Rank the following mutations with respect to their likelihood of affecting the structure of the polypeptide (from most likely to affect structure to least likely).1. insertion mutation in the middle of an intron2. deletion of 3 bases crossing an intron-exon border3. substitution mutation at the third position of a codon4. substitution mutation at the second position of a codon

2, 3, 4, 1

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'

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 codon on the mRNA strand codes for the amino acid carried by the aminoacyl-tRNA represented in the figure?

5'-UUC-3'

How is translation initiated?

All of the listed answers are correct.

Which of the following processes will occur at the exposed 3' end of a tRNA molecule?

An amino acid will bind covalently.

Which of the following processes occurs as part of transcription?

RNA is synthesized

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.

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 is true of a codon?

It can be either in DNA or in RNA.

Which of the following statements describes the effect of a nonsense mutation on a gene?

It introduces a premature stop codon into 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.

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.

Which of the following characteristics allows the CRISPR Cas9 enzyme to be an effective way to generate mutations that block the function of a specific protein (knock out)?

It's function is regulated by a complementary guide RNA

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.

What amino acid sequence will be generated based on the following mRNA codon sequence?

Met-Ser-Ser-Leu-Ser-Leu

Which one of the following statements is true of tRNAs?

None of the listed answers are correct

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 molecules are produced by transcription?

Ribozymes Messenger RNA

Which of the following characteristics of gene expression is shared by eukaryotic and prokaryotic cells?

Signal sequences are needed for the production of membrane proteins.

Two mRNAs (mRNA X and mRNA Y) are synthesized with the same exon sequences but poly-A tails of very different lengths. mRNA X is 7,500 bases long. mRNA Y is 6,900 bases long. The mRNA's are added to separate in vitro translation mixtures containing radioactive methionine and the reactions are allowed to proceed for 30 minutes. When the mixtures are analyzed which of the following outcomes will most likely occur?

The mRNA X mixture will contain more radioactive proteins than the mRNA Y mixture

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

Translation can begin while transcription is still in progress.

What is a ribozyme?

a biological catalyst made of RNA

All of the listed answers are correct.

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 most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the result of this type of mutation?

a polypeptide missing an amino acid

Post-translational modifications of proteins may include which of the following processes?

addition of carbohydrates to form a glycoprotein

RNA is single stranded, can hydrogen-bond with other nucleic acids, and has functional groups that can function in catalysis. These characteristics support that RNA could have which of the following cellular roles?

forming peptide bonds

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

from DNA to RNA to protein

After an RNA molecule is transcribed from a eukaryotic gene, what are removed, and what are spliced together, to produce an mRNA molecule with a continuous coding sequence?

introns, exons

Where does RNA polymerase begin transcribing a gene into mRNA?

it starts after a certain nucleotide sequence called a promoter

Which of the following molecular structures contains codons?

mRNA

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

Which of the following dipeptides will form from this mRNA?

proline-threonine

Which component is directly involved in translation?

ribosome

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

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

three, amino acid