Exam 3

How many amino acids are specified by a single codon? Multiple choice question. 3 2 1 20 twenty

1

During transcription, ribonucleotides are added to the Blank______. Multiple choice question. 3' end of the mRNA transcript 3' end of the leading strand of DNA 5' end of the lagging strand of DNA 5' end of the mRNA transcript

3' end of the mRNA transcript

A telomere has a sequence at the Blank______ that is termed a(n) Blank______ because it does not have a complementary strand. Multiple choice question. 3' end; primer 5' end; overhang 3' end; overhang 5' end; primer

3' end; overhang

What are mechanisms that significantly compact eukaryotic DNA? Multiple select question. Telomere formation 30-nm fibers 20-nm fibers Nucleosome formation

30-nm fibers Nucleosome formation

During the elongation stage of transcription, nucleotides bind to the template strand and are covalently connected in the Blank______ direction. Multiple choice question. 3' to 5' C-terminal to N-terminal N-terminal to C-terminal 5' to 3'

5' to 3'

Once replication has begun, new DNA can only be synthesized in ______a _____ to direction.

5, 3

How many different codons are found in our genetic code? Multiple choice question. 64 50 3 100 20

64

The total number of codons in our genetic code is __.

64

In the process of protein synthesis, what recognizes the three stop codons? Multiple choice question. The anticodon on an uncharged tRNA The large ribosomal subunit A protein called release factor Transcription factors

A protein called release factor

The start codon in mRNA is the triplet ___.

AUG

Which of these nucleotide sequences is the most commonly used start codon? Multiple choice question. AUG CCU AGU AUU UGA

AUG

What enzymes attach amino acids to tRNA molecules? Multiple choice question. Aminoacyl-tRNA transferases ATP synthases Aminoacyl-tRNA synthetases RNA polymerases

Aminoacyl-tRNA synthetases

What is a ribozyme? Multiple choice question. An enzyme that transcribes RNA A protein that splices RNA molecules A multisubunit complex that synthesizes proteins An RNA molecule that can catalyze a chemical reaction

An RNA molecule that can catalyze a chemical reaction

What part of a tRNA binds to the codon of a messenger RNA molecule? Multiple choice question. Anticodon Codon Attached amino acid Acceptor stem

Anticodon

The DNA-protein complex that makes up eukaryotic chromosomes is termed ______.

Chromatin

What structural features are common to all tRNAs? Multiple select question. Cloverleaf pattern with three stem-loops Acceptor stem for amino acid attachment Loop that attaches to the spliceosome A, P, and E sites

Cloverleaf pattern with three stem-loops Acceptor stem for amino acid attachment

The portion of an mRNA sequence that specifies the amino acid sequence of a polypeptide is called the _______ sequence.

Coding

Molecularly, a gene is an organized unit of Blank______ sequences that can be transcribed into RNA. Multiple choice question. DNA regulatory protein

DNA

Original DNA strands are used as templates to produce new DNA strands during the process called _______ _______.

DNA Replication

What enzyme covalently links nucleotides together? Multiple choice question. Phosphatase DNA polymerase DNA helicase Methylase

DNA polymerase

An origin of replication is a sequence in a chromosome that serves as a starting point for Blank______. Multiple choice question. RNA synthesis protein synthesis chromosome separation DNA synthesis

DNA synthesis

The process by which cells become specialized into particular types with distinct structures and functions is termed cell ________.

Differentiation

Identify the stage of translation in which polypeptide synthesis occurs. Multiple choice question. Elongation Termination Initiation

Elongation

The three stages of transcription are called initiation,________, and termination.

Elongation

Gene regulation allows bacteria to survive in response to ______ changes, such as the availability of specific nutrients.

Environment

Transcription is similar in bacteria and eukaryotes, except that ______ use more proteins.

Eukaryotes

How does gene regulation differ between prokaryotes and eukaryotes? Multiple choice question. Only eukaryotes can regulate the translation of mRNA into protein. Eukaryotes process mRNA transcripts in ways that prokaryotes do not. Only eukaryotes can regulate transcription. Eukaryotic proteins may be affected by post-translational regulatory mechanisms, such as feedback inhibition.

Eukaryotes process mRNA transcripts in ways that prokaryotes do not.

One difference between RNA processing of bacteria versus eukaryotes is that mRNA transcripts undergo RNA processing or modification that is needed for proper translation in ______ cells.

Eukaryotic

How does transcription differ in eukaryotes and bacteria? Multiple choice question. Eukaryotic transcription requires more proteins. Eukaryotic transcription does not require a promoter sequence. The initiation stage of transcription is more complex in bacteria. Bacteria have more types of RNA polymerase.

Eukaryotic transcription requires more proteins.

Gene function either at the molecular level or at the level of traits is referred to as gene _______.

Expression

What are two major benefits of gene regulation? Multiple select question. Production of ATP Expression of genes at appropriate times Production of all proteins simultaneously The conservation of energy

Expression of genes at appropriate times The conservation of energy

True or false: In eukaryotes, pre-mRNA molecules can be translated immediately without the need for modifications. True or False

False

The functional product of genes arises from what process? Multiple choice question. Gene expression RNA interference DNA methylation Genomic stability Gene silencing

Gene expression

What term refers to gene function at the level of traits or at the molecular level? Multiple choice question. Gene expression Genetic variation Gene duplication

Gene expression

What is the process by which a cell controls the level of expression of a specific gene or set of genes in a biological pathway? Multiple choice question. Protein synthesis Gene expression Gene regulation RNA processing

Gene regulation

In mammals, the protein that delivers oxygen to body cells is _____.

Hemoglobin

Eukaryotic DNA wraps around a group of proteins to compact itself and to form nucleosomes. These proteins are called ______.

Histone

In eukaryotes, DNA is compacted by wrapping itself around what group of proteins? Multiple choice question. Histones Centrosomes Chromophores Nucleosomes

Histones

What is the function of the anticodon of a tRNA molecule? Multiple choice question. It catalyzes the formation of peptide bonds. It binds to a codon on an mRNA molecule. It has an amino acid covalently attached to it. It base pairs with sequences on the rRNA.

It binds to a codon on an mRNA molecule.

What is the purpose of the genetic code? Multiple choice question. It explains how chromosomes behave during meiosis. It specifies the relationship between mRNA and polypeptide sequences. It describes the flow of information from DNA to RNA to protein.

It specifies the relationship between mRNA and polypeptide sequences.

During DNA replication, the strand that is synthesized continuously is the ______ strand, while the ______ strand is synthesized as small fragments that are connected to each other to form a continuous strand.

Leading; Lagging

Changes in genetic material that can be inherited are known as _______.

Mutations

What occurs when genetic material, that can be inherited, is changed? Multiple choice question. Duplications Stagnations Mutations

Mutations

The 30-nm fiber is comprised of _______ units organized into a more compact structure.

Nucleosome

A coding sequence specifies the amino acid sequence of a(n) ______.

Polypeptide

A short RNA strand is required to initiate the process of DNA replication. This RNA is synthesized by the enzyme ______.

Primase

DNA polymerase can detect a mismatched nucleotide and remove it from the daughter strand. It does so by digesting the linkages in the 3' to 5' direction to remove the incorrect base and then changing direction to synthesize again in the 5' to 3' direction. This process is called ______.

Proofreading

The characteristics of an organism are rooted in the activities of cellular _______ encoded by genes.

Proteins

The chromatin that makes up eukaryotic chromosomes is a complex of what? Multiple select question. RNA Proteins Lipids DNA Polysaccharides

Proteins DNA

The collection of all proteins that are expressed in a cell is known as the _______.

Proteome

At the molecular level, a gene is defined as an organized unit of DNA sequences that enables a segment of DNA to be transcribed into ______ , resulting in the formation of a functional product.

RNA

In transcription, a sequence of _____ is copied into a sequence of _______ .

RNA; DNA

The ability of cells to control the expression of genes is termed gene ______.

Regulation

During translation, the stop codons are recognized by a protein called a(n) ______ factor.

Release

Two new molecules of DNA are the product of which process? Multiple choice question. Transcription Translation Replication Reverse transcription Transduction

Replication

Translation occurs on structures called ______.

Ribosome

What is the site of translation? Multiple choice question. Ribosome Nucleus Plasma membrane Golgi apparatus

Ribosome

An RNA molecule that catalyzes a chemical reaction is called a(n) ______.

Ribozymes

The enzyme that attaches DNA sequences at the ends of eukaryotic chromosomes is called _____.

Telomerase

Which of the following enzymes prevents chromosomal shortening in eukaryotes by attaching a repeat sequence to the ends of chromosomes? Multiple choice question. Topoisomerase Telomerase DNA polymerase III Helicase DNA polymerase α

Telomerase

The region at the ends of eukaryotic chromosomes are called _____.

Telomeres

What part of a gene signals the end of transcription? Multiple choice question. Stop codon Silencer Promoter Regulatory region Terminator

Terminator

When are the genes involved in lactose metabolism in E. coli expressed and when are they turned off? Multiple choice question. The genes for lactose metabolism are expressed when lactose is present but not when it is absent. The genes for lactose metabolism are turned off when lactose is present and when it is absent. The genes for lactose metabolism are expressed when lactose is absent but not when it is present. The genes for lactose metabolism are expressed when lactose is present and when it is absent.

The genes for lactose metabolism are expressed when lactose is present but not when it is absent.

What can explain the remarkably high fidelity for DNA replication? Multiple select question. DNA polymerases that are prone to make errors are destroyed by the cell prior to replication. The hydrogen bonding between AT and CG pairs is more stable than between mismatched pairs. DNA polymerase is unlikely to catalyze bond formation between adjacent nucleotides if a mismatched base pair is formed. DNA polymerase can identify and replace mismatched nucleotides.

The hydrogen bonding between AT and CG pairs is more stable than between mismatched pairs. DNA polymerase is unlikely to catalyze bond formation between adjacent nucleotides if a mismatched base pair is formed. DNA polymerase can identify and replace mismatched nucleotides.

What is cell differentiation? Multiple choice question. The process by which cells express specific genes only when needed The process by which cells acquire different DNA sequences as they develop The process by which cells become specialized in different types The process by which cells can attach together to form a multicellular organism

The process by which cells become specialized in different types

Which RNA molecule involved in translation acts as an intermediary between an mRNA codon and an amino acid? Multiple choice question. The snRNA The rRNA The tRNA The pre-mRNA

The tRNA

In bacterial protein synthesis, how do the mRNA and the 16S rRNA bind to one another? Multiple choice question. They are covalently attached to one another by the spliceosome. They are covalently attached to one another by ribosomal proteins. They base pair with each other. They associate indirectly via the initiator tRNA.

They base pair with each other.

Which of the following statements about DNA polymerases is true? Multiple choice question. They synthesize DNA in the 3' to 5' direction only. They synthesize DNA in the 5' to 3' direction only. They synthesize DNA either in the 5' to 3' or 3' to 5' directions, depending on the orientation of the template strand. They synthesize DNA either in the 5' to 3' or 3' to 5' directions, depending on the availability of a promoter sequence.

They synthesize DNA in the 5' to 3' direction only.

Why do eukaryotic cells have multiple origins of replication? Multiple choice question. So that both strands of DNA can serve as templates to produce new strands So that the new strands can meet at the ends of the circular chromosomes To ensure timely replication of multiple, relatively large chromosomes

To ensure timely replication of multiple, relatively large chromosomes

An RNA copy of a gene is produced via the process of _____.

Transcription

The copying of DNA into RNA occurs in the process called _______.

Transcription

The promoter of a gene signals the beginning of what? Multiple choice question. Translation Splicing Transcription Polyadenylation Replication

Transcription

Like transcription, the process of _______ occurs in three stages called initiation, elongation, and termination.

Translation

At what levels does gene regulation occur in bacteria? Multiple select question. mRNA processing Replication Translation Transcription Post-translation

Translation Transcription Post-translation

The structural features common to all transfer RNAs include a middle stem-loop containing a(n)______ that is complementary to the codon on mRNA and a 3' single-stranded region that is a(n) _______ attachment site.

anticodon; amino acid

The formation of nucleosomes and their arrangement into a 30-nm fiber are important because they Blank______. Multiple choice question. compact bacterial DNA compact eukaryotic DNA assemble the lagging strand assist in proofreading during DNA replication

compact eukaryotic DNA

When cells prepare to divide, the chromosomes become Blank______ to aid in proper alignment. Multiple choice question. loosely compacted less coiled incorrect condensed

condensed

The covalent bonding of amino acids to each other, one at a time, occurs during the _____ stage of translation.

elongation

The process in which the information in a gene is made into a functional gene product, such as an RNA molecule or a protein, is termed gene ______.

expression

Multicellular organisms ensure that most proteins are produced at appropriate times and in appropriate cell types via the _______ regulation of the that encode these proteins.

genes

The Blank______ that constitute the genetic material provide a blueprint for the characteristics of every organism. Multiple choice question. organelles cells membranes genes

genes

A typical eukaryotic chromosome is Blank______ and contains Blank______ origin(s) of replication. Multiple choice question. circular; a single linear; a single linear; multiple circular; multiple

linear; multiple

The genetic code specifies the relationship between the sequence of nucleotides in Blank______ and the sequence of amino acids in a polypeptide. Multiple choice question. mRNA rRNA tRNA

mRNA

A metaphase chromosome is Blank______ a chromosome in a non-dividing cell. Multiple choice question. more condensed than as condensed as less condensed than

more condensed than

In E. coli, the genes required to metabolize lactose are expressed Blank______. Multiple choice question. only when lactose is absent independently of lactose only when lactose is present

only when lactose is present

The site within a chromosome where DNA replication begins is termed the _____ of replication.

origin

If a person inherits two mutant genes that encode hydroxyphenylpyruvate oxidase, what metabolite will accumulate? Multiple choice question. p-Hydroxyphenylpyruvic acid Maleylacetoacetic acid Tyrosine Phenylalanine Homogentisic acid

p-Hydroxyphenylpyruvic acid

The accumulation of high levels of phenylalanine in the blood would most likely be the result of mutations in the gene that encodes Blank______. Multiple choice question. phenylalanine hydroxylase homogentisic acid oxidase hydroxyphenylpyruvate oxidase tyrosine aminotransferase

phenylalanine hydroxylase

The accumulation of high levels of phenylalanine in the blood would most likely be the result of mutations in the gene that encodes Blank______. Multiple choice question. tyrosine aminotransferase hydroxyphenylpyruvate oxidase phenylalanine hydroxylase homogentisic acid oxidase

phenylalanine hydroxylase

During DNA replication, the enzyme that covalently links nucleotides to synthesize new DNA strands is DNA _______.

polymerase

In order to start DNA synthesis on a bare template, the enzyme Blank______ is needed. Multiple choice question. helicase polymerase primase topoisomerase

primase

Transcription begins at a site in DNA called the Blank______. Multiple choice question. terminator initiator start codon promoter

promoter

Bacteria respond to changes in their environment by Blank______. Multiple choice question. regulating their genes shutting down protein synthesis mutating into resistant forms going into a dormant state

regulating their genes

The most current model of chromatin structure suggests that the linker regions in the 30-nm structures are Blank______. Multiple choice question. relatively straight with little direct contact between nucleosomes bent and twisted with little direct contact between nucleosomes relatively straight with extensive direct contact between nucleosomes bent and twisted with extensive direct contact between nucleosomes

relatively straight with little direct contact between nucleosomes

In a transcriptional unit, the function of the terminator is to Blank______. Multiple choice question. influence the rate of transcription signal the beginning of transcription signal the end of transcription

signal the end of transcription

The enzymes that catalyze the attachment of amino acids to tRNA molecules are known as aminoacyl-tRNA _______.

synthetases

The molecule that is attached to an amino acid and has an anticodon that can base pair with a codon is called ______.

tRNA

During the initiation stage of translation in bacteria, the mRNA first binds to Blank______. Multiple choice question. a molecule of GTP an initiator tRNA an initiation factor the 5S rRNA of the large ribosomal subunit the 16S rRNA of the small ribosomal subunit

the 16S rRNA of the small ribosomal subunit

A codon in a messenger RNA molecule consists of Blank______ nucleotides. Each mRNA codon specifies Blank______ amino acid(s). Multiple choice question. two; one three; three three; one two; three

three; one

The synthesis of an RNA copy of a gene is called Blank______. Multiple choice question. splicing translation replication transcription mutation

transcription