Biol 1009 topic 17 & 18

The enzyme polynucleotide phosphorylase randomly assembles nucleotides into a polynucleotide polymer. You add polynucleotide phosphorylase to a solution of ATP, GTP, and UTP. How many artificial mRNA 3 nucleotide codons could possibly be made?

27

The nucleotide sequence of the coding strand of a DNA molecule is shown below. What will be the nucleotide sequence of the RNA molecule made from this segment of DNA?5' ATGCGTA 3'

5' AUGCGUA 3'

Which of the following correctly shows the flow of information in a cell?

DNA to RNA to protein

Which of the following statements about RNA processing is FALSE?

Exons are cut out before mRNA leaves the nucleus.

Which of the following statements about a codon is FALSE? It never codes for more than one amino acid. It may code for the same amino acid as another codon. It consists of three nucleotides. It extends from one end of a tRNA molecule.

It extends from one end of a tRNA molecule.

In comparing DNA replication with transcription, which of the following is true only of DNA replication?

The entire template molecule is represented in the product.

The group of three nucleotides that specifies an amino acid is known as a

codon

The anticodon of a particular tRNA molecule is

complementary to the corresponding mRNA codon.

A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that

many noncoding stretches of nucleotides are present in mRNA.

Transfer RNAs, or tRNAs are translated to form short polypeptides that are part of ribosomes. are important components of ribosomes form 3-dimensional shapes as a result of ionic bonds between

none of these answers are correct

The proteins that help RNA polymerase bind the DNA at the promoter site are known as

transcription factors

How many different amino acids could be specified if codons were two nucleotides in length?

16

Given the locally unwound double strand below, in which direction does the RNA polymerase move?

3' → 5' along the template strand

The nucleotide sequence of the template strand of a DNA molecule is shown below. What will be the nucleotide sequence of the RNA molecule made from this segment of DNA?5' AATTCGGG 3'

5' CCCGAAUU 3'

Which of the follwing statements are true? a)Many prokaryotic primary mRNA molecules have "intervening" sequences, or introns, that do not code for proteins. b)5' and 3' untranslated regions (UTRs) are parts of exons, but do not code for proteins. c)Many prokaryotic genes have "intervening" sequences, or introns, that do not code for proteins. You Answered All of these statements are true.

5' and 3' untranslated regions (UTRs) are parts of exons, but do not code for proteins.

The enzyme polynucleotide phosphorylase randomly assembles nucleotides into a polynucleotide polymer. You add polynucleotide phosphorylase to a solution of adenosine triphosphate and guanosine triphosphate. How many different artificial mRNA 3 nucleotide codons could possibly be made?

8

A particular triplet of bases in the coding strand of a gene is GGG. If an mRNA is made from this gene, the anticodon on the tRNA that will bind the codon on the mRNA is

CCC

Which component is not directly involved in translation?

DNA

Which of the following statements is TRUE? RNA is transcribed and proteins are translated DNA is translated and RNA is transcribed RNA is translated and proteins are transcribed DNA is transcribed and RNA is translated

DNA is transcribed and RNA is translated

What is meant by the statement that "the genetic code is redundant"?

Most amino acids are specified by more than one codon.

A particular triplet of bases in the coding strand of a gene is AAA. If an mRNA is made from this gene, the anticodon on the tRNA that will bind the codon on the mRNA is

UUU

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the MOST serious effect on the polypeptide product?

a deletion of two nucleotides

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

Transfer RNAs, or tRNAs bind only a specific amino acid have 3-dimensional shapes that are formed by hydrogen bonding between the nitrogenous bases of some of the ribonucleotides comprising the tRNA contain an anticodon that base pairs with an appropriate codon on a mRNA molecule

all of these answers are correct

Which of the following are needed for the initiation of transcription? RNA polymerase a promoter sequence transcription factors

all of these answers are correct

Which of the following statements about translation is TRUE? a)mRNA molecules are read by the translation machinery in the 5' to 3' direction. b)The 5' and 3' UTRs of an mRNA molecule are not translated. c)Translation of an mRNA begins at an AUG codon d) All of these statements are true.

all of these statements are true

Which of the following statements about translation is TRUE? mRNA molecules are read by the translation machinery in the 5' to 3' direction. The 5' and 3' UTRs of an mRNA molecule are not translated. Translation of an mRNA begins at an AUG codon

all of these statements are true

Translation of mRNA

almost always begins at an AUG codon, which specifies methionine

When the ribosome reaches a stop codon on the mRNA, no corresponding tRNA enters the A site. If the translation reaction were to be experimentally stopped at this point, which of the following would you be able to isolate?

an assembled ribosome with a polypeptide attached to the tRNA in the P site

Ribosomal RNAs, or rRNAs

are not translated to form proteins

During translation, the role of release factors is to

bind the mRNA stop codon in the A site of the ribosome, causing release of the completed polypeptide

Which of the following types of RNA molecules have polyA tails?

eukaryotic mRNA molecules

Which of the following is NOT a typical modification of a eukaryotic primary (or precursor) mRNA?

phosphorylation

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

proline-threonine.

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

several transcription factors (TFs)

The DNA strand to which ribonucleotides hydrogen bond during transcription is known as the

template strand

Scientists sometimes transfer genes from one species to a different species. What property of the genetic code typically allows these genes to produce a protein of the same amino acid sequence in the new species as they did in the original species?

the genetic code is almost universal

During translation, after the ribosome breaks the bond between the growing polypeptide chain and the tRNA in the P site and then forms a covalent (peptide) bond between the growing polypeptide chain and the amino acid attached to the tRNA in the A site,

the ribosome shifts over one codon on the mRNA, such that the codon specifying the next amino acid is now lined up with the A site

Which of the following help form a transcription complex at a promoter?

transcription factors and RNA polymerase