BSC - Chapter 7 SmartBook

In the DNA double helix, the two backbones are composed of alternating

sugar and phosphate groups.

During translation elongation, what molecule brings amino acids to the ribosome, as dictated by the sequence of codons on the mRNA?

tRNA

The promoter is a sequence on the ______ that signals the start of a gene.

template strand of DNA

Which of the following best describes translation?

the "reading" of an mRNA to produce a protein

Wilkins and Franklin performed X-ray diffraction that revealed details about

the three-dimensional shape of the DNA molecule.

A major difference between eukaryotic and prokaryotic chromosomes is that in eukaryotes, multiple, linear chromosomes are housed within an organelle called the ___________ , and each chromosome consists of DNA associated with proteins.

Nucleus

What RNA modification in eukaryotes decreases the chances that the mRNA will be degraded before translation?

Poly A tail

RNA ______ is the enzyme that builds the RNA chain during transcription.

Polymerase

Enzymes and chaperone proteins assist in ______ that takes place after translation is complete.

Polypeptide folding

The ______ is a sequence of DNA that signals the start of a gene and is the site where RNA polymerase binds to begin transcription.

Promoter

Messenger RNA carries information that specifies the amino acid sequence of a

Protein

In the "central dogma," information flows from DNA to RNA to

Proteins

In the base pairs of the DNA double helix,

a double-ring base always pairs with a single-ring base.

Bacterial genomes normally consist of ______ chromosome(s), whereas eukaryotic genomes are normally made up of ______ chromosome(s).

a single circular; multiple linear

What describes a ribosome?

an rRNA-protein structure that is the site of translation

If the DNA double helix resembles a ladder, the interior "rungs" of the DNA ladder consist of

nitrogenous bases joined by hydrogen bonds.

In the synthesis of RNA from DNA, the enzyme RNA polymerase adds ______ to the ______ end of the growing RNA molecule.

nucleotides; 3 prime

Transcription factors are eukaryotic proteins that are required for RNA polymerase to bind to a promoter and initiate

transcription of genes.

1. Erwin Chargaff 2. Maurice Wilkins and Rosalind Franklin 3. James Watson and Francis Crick

1. Determined that DNA contains equal amounts of adenine and thymine and of guanine and cytosine 2. Used X-ray diffraction to determine that DNA has a regular, repeating structure of building blocks 3. Used the known ratios of nucleotides along with the X-ray diffraction data to build a ball-and-stick model of the DNA double helix

Select all of the following that are true about prokaryotic versus eukaryotic gene expression.

1. In eukaryotes, the nuclear membrane separates transcription from translation. 1. In eukaryotes, mRNA is altered before it leaves the nucleus.

Select all of the following that are true with respect to genomes.

1. In prokaryotic cells, the genome usually consists of just one circular DNA molecule. 2. In eukaryotic cells, the genome is usually divided up into multiple chromosomes.

Match each eukaryotic regulatory mechanism with where it would act within the "central dogma." 1. DNA availability matches 2. mRNA processing, mRNA exit from the nucleus 3. protein degradation 4. transcription factors matches

1. Occurs before transcription occurs before transcription 2. occurs after transcription but before translation 3. occurs after translation 4. Occurs at initiation of transcription occurs at initiation of transcription

Arrange the events of transcription in the order that they occur, beginning with the first event at the top.

1. RNA polymerase binds to the gene's promoter. 2. RNA polymerase moves down the DNA template strand, producing a complementary RNA molecule. 3. RNA polymerase separates from the DNA and the newly synthesized RNA is released.

Select all of the effects on the lac operon when the repressor is bound to the operator.

1. RNA polymerase is unable to initiate transcription. 2. The bacterial cell conserves energy by not producing lactose-degrading enzymes.

Select all of the following that are involved in transcription initiation in eukaryotes.

1. TATA box 2. RNA polymerase 3. promoter 4. enhancers 5. transcription factors

Place these translation initiation and elongation events in order from the first step at the top to the last step at the bottom. Instructions

1. The 5' end of the mRNA molecule binds with the small ribosomal subunit. 2. The first tRNA binds to the start codon on the mRNA molecule. 3. The large ribosomal subunit binds to the small ribosomal subunit. 4. The second tRNA molecule binds to the second codon on the mRNA molecule. 5. A covalent bond is formed between the two amino acids. 6. The ribosome releases an empty tRNA.

Select all of the following that are true about the genetic code.

1. The same genetic code is used by nearly all species. 2. There are three codons that act as "stop" codons. 3. AUG encodes methionine and "start."

Select all the statements about nucleotides that are accurate.

1. They are composed of a sugar, a nitrogen-containing base, and one or more phosphorus-containing groups. 2. DNA always contains the same sugar in its nucleotides.

Select all of the following that are true about codons.

1. They correspond to one amino acid. 2. They are composed of three mRNA bases.

Select all of the following that are "stop" codons, which signal the end of translation.

1. UGA 2. UAG 3. UAA

Select all of the following organisms that have introns in their primary mRNA transcripts.

1. animals 2. eukaryotes 3. archaea

Select all of the following that are affected by epigenetic modifications in eukaryotes.

1. developmental patterns 2. cell division 3. gene expression

During production of a protein, the information encoded in a DNA base sequence is transcribed to produce a molecule of _______ , which is then processed and translated to produce the sequence ________ of acids in a protein.

1. mRNA 2. amino

Select all of the following that are genes.

1. sequence of DNA nucleotides that codes for a specific protein 2. sequence of DNA nucleotides that codes for a specific RNA molecule

Select all of the following that are methods of gene regulation found in eukaryotes but not prokaryotes.

1. splicing exons in alternative ways 2. adding methyl groups to silence genes 3. blocking mRNA exit from the nucleus

Select all of the following that are utilized in the process of translation.

1. tRNA 2.amino acids 3. ribosome 4. mRNA

Select all of the reasons why eukaryotic cells regulate gene expression.

1. to express different subsets of genes in different types of cells 2. to coordinate early development 3. to activate different genes at different times in the life of an organism

Select all the reasons a cell regulates gene expression

1. to respond to changing conditions 2. to have a specialized function

Select all of the following that are actions of the enzyme RNA polymerase.

1. unzip the DNA to expose the template strand 2. build an mRNA chain 3. attach to the promoter on DNA

Select all the ways that cells can make DNA less available for transcription.

1. wind DNA more tightly 2. tag DNA with methyl groups

During transcription, RNA polymerase moves along the DNA template strand, adding RNA nucleotides to the growing ______ end of the RNA molecule.

3'

The mRNA sequence ______ codes for the amino acid sequence Met-Trp-Arg.

AUGUGGAGG

Most of the epigenetic markers present in a multicellular organism are placed onto its DNA

After the sperm and egg cell unite in fertilization.

On a tRNA molecule, the ________is a three-base sequence that is complementary to and binds to an mRNA codon during translation.

Anticodon

What 3-base site of a tRNA molecule is complementary to an mRNA codon?

Anticodon

What is a discrete package of DNA and its associated proteins?

Chromosome

In an RNA molecule, a(n) ______ is a genetic "code word" that corresponds to one amino acid.

Codon

During the elongation phase of translation, a _______ bond is formed between the incoming _______ acid and the growing polypeptide chain, and empty tRNAs are released from the ribosome to be reused.

Covalent; amino

During transcription, RNA nucleotide bases bind with the exposed complementary bases on the template strand of

DNA

Hershey and Chase showed that the part of a virus that could enter bacterial cells and cause the production of more viruses was

DNA

The information that each cell needs to produce proteins is stored in a molecule called

DNA

A eukaryotic chromosome consists of

DNA wrapped around histones and other proteins.

DNA has a ______ helical structure consisting of two intertwining strands of ______.

Double; nucleotides

In eukaryotes, transcription factors can bind at near or distant regulatory DNA sequences called

Enhancers

What are coding regions of eukaryotic mRNA that are translated?

Exons

_________ are portions of mRNA that get spliced together to form mature mRNA prior to translation. Multiple choice question.

Exons

After translation is complete, the newly synthesized polypeptide must ______, as determined by some regions of the amino acid chain.

Fold into its functional shape

The ______ describes the correspondence of three-nucleotide codons to specific amino acids or directions for starting and stopping translation.

Genetic code

All of the genetic material that is within a cell is called its

Genome

The DNA double ________ resembles a twisted ladder, where each rail of the "ladder" (each backbone) is composed of alternating deoxyribose sugars and __________ groups joined together by __________ bonds.

Helix; phosphate; covalent

What is one major difference between eukaryotes and prokaryotes with respect to translation?

In prokaryotes, translation can take place even before transcription is complete.

A(n) is a portion of RNA that averages about 1,000 nucleotides long and that is removed before translation.

Intron

The lac operon in E. coli bacteria includes three genes that produce

Lactose-degrading proteins.

Each ribosome has one _________ subunit and one _____ subunit that join at the initiation of protein synthesis.

Large; small

A gene is a sequence of DNA nucleotides that encodes a specific protein or

RNA molecules

During transcription, what enzyme attaches to the promoter, unzips the DNA double helix, and adds complementary RNA nucleotides?

RNA polymerase

initiation

RNA polymerase binds to the gene's promoter.

elongation

RNA polymerase moves down the template strand, adding nucleotides and producing a complementary RNA molecule.

termination

RNA polymerase separates from the DNA and the newly synthesized RNA is released.

A complex of rRNA and proteins called a(n) ___________is the physical location of protein synthesis.

Ribosome

What structures are the sites of protein synthesis and are found free in the cytosol of the cell or attached to the rough endoplasmic reticulum?

Ribosomes

In his experiments with S. pneumoniae bacteria and mice, Frederich Griffith found that

Something in heat-killed S bacteria could transform type R bacteria

When the ribosome exposes a UGA, UAG, or UAA codon on the mRNA during translation, release factors rather than tRNAs bind to these codons, which is why these three sequences are called _____ codons.

Stop

What role does DNA play in the cell?

Store genetic information

The DNA strand that is "read" during transcription is called the ______ strand.

Template

A specific sequence on the DNA called a(n) ______ sequence signals the end of a gene during transcription.

Terminator

In the 1950s, the biochemist Erwin Chargaff found that in DNA, the amount of the nucleotide base adenine always equals the amount of the nucleotide base ________ , and the amount of the nucleotide base cytosine always equals the amount of the nucleotide base __________

Thymine; Guanine

Eukaryotic cells can compact their DNA or add methyl groups to make their DNA unavailable for

Transcription

In what process does the cell make a complementary RNA molecule from a DNA sequence?

Transcription

In the "central dogma" describing the flow of genetic information from DNA to protein, DNA is copied to RNA in a process called ______ , and the information in RNA is used to direct the synthesis of a protein in a process called ________.

Transcription; translation

In what process does the cell use the information in an RNA molecule to assemble a protein?

Translation

True or false: Unlike DNA, RNA can catalyze chemical reactions.

True

In eukaryotic cells, the mRNA is altered before it leaves the nucleus. A short sequence of modified nucleotides, known as a ______ is added to the 5' end and a string of adenines called a ______ is added to the 3' end.

cap; poly-A tail

The regulation of gene expression in eukaryotic cells allows for

cell specialization in multicellular eukaryotes.

Regulating gene expression allows cells to produce

certain proteins only when they are needed.

The terms 3' and 5' refer to numbered carbon atoms within the ______ of DNA, and at one end of the DNA double helix, there is a free ______ on one backbone and a free ______ on the other backbone.

deoxyribose sugar; 3' carbon; 5' carbon

Modifications to DNA, such as methylation, that do not change the nucleotide sequence but do affect gene expression are called ______ modifications.

epigenetic

Whereas _____ wipes away most epigenetic markers on the genome, _____ does not; therefore, identical twins may accumulate epigenetic differences throughout life.

fertilization; cell division

Select all of the following that are functions of the 5' cap and 3' poly A tail added to mRNA after transcription in eukaryotes.

help ribosomes attach to 5' end of mRNA protect RNA from degradation

As described by Jacob and Monod, what E. coli genes and regulatory sequences are only produced when the bacteria need to break down lactose in the immediate environment?

lac operon

Transcription of the three genes in the lac operon occurs when

lactose is present in the environment and binds to the repressor.

When Griffith mixed together live strain R bacteria and heat-killed S bacteria and injected them into mice, the mice died, and ______ bacteria were isolated from the mice, indicating that something could pass between cells and transform them.

live S strain

In transcription, the genetic information in DNA is copied into a(n) ______ molecule, and in translation, the "message" in an mRNA molecule is translated into a(n) ______ sequence.

mRNA; amino acid

During the elongation stage of translation, the ribosome exposes codons on the ______ one at a time; each codon determines what ______ will bring its attached amino acid to the ribosome to be added to the polypeptide chain.

mRNA; tRNA

The type of RNA that carries the information to specify a protein is called

messenger RNA (mRNA).

Where would you find a transcriptional terminator sequence?

on a DNA sequence

In the Hershey and Chase experiment, ______ was found inside the infected bacteria, indicating that the labeled viral ______ had entered the bacterial cells to direct new virus production.

radioactive phosphorus; DNA

Which of the following best describes transcription?

using a DNA template to synthesize RNA