Micro Chapter 7

The molecule that encodes all the instructions needed to produce a cell's components is ______.

Multiple choice question.

RNA

protein

DNA

DNA

The functional unit of a genome that codes for a product is a(n)______

gene

All DNA nucleotides contain the same deoxyribose and phosphate groups, but different ._________

nucleobases

RNA contains the sugar _____, which differs from its DNA counterpart by possessing _____ oxygen atom.

Multiple choice question.

ribose; one more

ribose; one fewer

ribulose; one fewer

ribulose; one more

ribose; one more

Regulating gene expression involves controlling mRNA synthesis and rapidly destroying mRNA transcripts.

True false question.

True

Fals

True

An essential macromolecule that encodes all of the information needed by a cell to synthesize its components is ._____

DNA

To initiate replication of a DNA molecule, specific proteins must bind to a specific DNA sequence called the ______.

Multiple choice question.

start sequence

origin of replication

beginning point

origin of replication

A ______ is a sequence of nucleotides that usually codes for one functional protein.

Multiple choice question.

gene

triplet

codon

protein

chromosome

genome

gene

DNA replication must occur prior to cell division to ensure that each new cell has a complete genome.

True false question.

True

False

True

Which of the following is found in all DNA nucleotides?

Multiple choice question.

the same sugar, but different phosphates and nucleobases

the same nucleobase and phosphate, but different sugars

the same nucleobase, but different phosphates and sugars

the same sugar and phosphate, but different nucleobases

the same sugar and phosphate, but different nucleobases

The pentose sugar in RNA is________ , while in DNA the pentose sugar is ________

ribose and deoxyribose

Why is regulation of gene expression important?

Multiple choice question.

The cell needs a "rest period" when making protein.

A cell does not need all of its encoded proteins at the same time.

A cell can only express certain genes at any one time.

A cell does not need all of its encoded proteins at the same time.

A replication fork is ______.

Multiple choice question.

a site where one DNA strand serves as a template for the synthesis of an RNA transcript

a structure formed only during replication of a circular chromosome

a Y-shaped structure where both DNA strands are be

a Y-shaped structure where both DNA strands are being replicated

In general, the chromosome of a bacterial cell is a _______ DNA molecule that is replicated _______.

Multiple choice question.

circular; bidirectionally from multiple origins of replication

linear; bidirectionally from one origin of replication

circular; bidirectionally from one origin of replication

circular; unidirectionally from one origin of replication

linear; bidirectionally from multiple orgins of replication

circular; bidirectionally from one origin of replication

In this image of a bacterial chromosome replicating, the openings the labels are pointing to are called the _______ ________

replication forks

Cells duplicate their DNA before cell division using a process called DNA _________

replication

Because the newly made double helices are composed of one strand from the original molecule and one newly synthesized strand, DNA replication is said to be ._________

semiconservative

All DNA nucleotides contain the same deoxyribose and phosphate groups, but different ._______

nucleobases

How many template strands exist in a replication fork?

Multiple choice question.

only one

four

unlimited number

two

two

RNA contains the sugar _____, which differs from its DNA counterpart by possessing _____ oxygen atom.

Multiple choice question.

ribose; one more

ribose; one fewer

ribulose; one fewer

ribulose; one more

ribose; one more

A(n)_______ ________ is a Y-shaped point on a replicating DNA molecule where the DNA polymerases are synthesizing new strands of DNA.

replication fork

How many replication forks are formed from opening a section of a circular DNA molecule as part of DNA replication?

Multiple choice question.

2

4

1

2

What enzyme synthesizes the short segments of RNA required to initiate DNA replication?

Multiple choice question.

DNA gyrase

primase

DNA polymerase

ligase

helicase

primase

DNA replication is described as being ______, because each new DNA molecule formed by the process has one original strand and one newly synthesized strand.

Multiple choice question.

complementary

conservative

antiparallel

semiconservative

semiconservative

After the initiation of replication of a bacterial chromosome, the enzyme _______ adds nucleotides to a growing strand.

Multiple choice question.

DNA polymerase

Primase

RNA polymerase

DNA ligase

DNA polymerase

The single-stranded DNA from which a new DNA strand is synthesized is referred to as the ______.

Multiple choice question.

origin of replication

complement

nucleotide

transcript

template

template

Which strand is replicated continuously during DNA replication?

Multiple choice question.

The lagging strand only

Neither the leading nor lagging strands

The leading strand only

Both the leading and lagging strands

The leading strand only

In DNA replication, the DNA strand that is synthesized continuously is the ______ strand, while the strand that is synthesized discontinuously is the ______ strand.

Multiple choice question.

leading; fragmented

leading; lagging

leading; Okazaki

lagging; leading

leading; lagging

To initiate DNA replication, short sequences of RNA are needed. These are called —————

primer

The DNA strand that is synthesized discontinuously during DNA replication, forming Okazaki fragments, is called the______ strand.

lagging

During replication, DNA polymerases ______.

Multiple choice question.

add nucleotides to the 3' end of the new DNA strand

add nucleotides to the 5' end of the new DNA strand

generate short stretches of RNA called primers to initiate replication

unwind the DNA double helix at the replication fork

add nucleotides to the 3' end of the new DNA strand

During transcription, RNA polymerase synthesizes ______ from a(n) ______ template.

Multiple choice question.

RNA; protein

RNA; DNA

DNA; RNA

RNA; RNA

RNA; DNA

In DNA replication, the synthesis of one new strand proceeds continuously as fresh template is exposed. This strand is known as the ______ strand.

leading

This is an image of a replication fork. The top (blue) arrow is pointing to the __________ strand, and the bottom (red) arrow is pointing to the_________ strand.

leading, lagging

What enzyme binds to a DNA promoter region to initiate transcription?

Multiple choice question.

DNA gyrase

RNA synthase

DNA polymerase

RNA polymerase

Primase

RNA polymerase

As part of DNA replication, Okazaki fragments are made during the synthesis of the ______.

Multiple choice question.

lagging strand in a discontinuous manner

lagging strand in a continuous manner

leading strand in a continuous manner

leading strand in a discontinuous manner

lagging strand in a discontinuous manner

After the initiation of replication of a bacterial chromosome, the enzyme _______ adds nucleotides to a growing strand.

Multiple choice question.

Primase

DNA polymerase

RNA polymerase

DNA ligase

DNA polymerase

An RNA transcript is a strand of RNA copied from an RNA template.

True false question.

True

False

False

The process of transcription stops when the RNA polymerase reaches a ______.

Multiple choice question.

terminator

promoter

ender

silencer

terminator

An RNA transcript is synthesized in the 3' to 5' direction.

True false question.

True

False

False

Transcription is carried out by an enzyme called .___________ ____________

RNA polymerase

The DNA strand that is synthesized discontinuously during DNA replication, forming Okazaki fragments, is called the ____lstrand.

lagging

The ______ DNA strand is used as the template for RNA synthesis.

Multiple choice question.

plus (+)

minus (-)

minus (-)

During what process is the information in mRNA used to make a protein?

Multiple choice question.

replication

transcription

translation

transduction

translation

RNA polymerase binds to a ______ to begin transcription.

Multiple choice question.

initiator

terminator

promoter

primer

promoter

RNA polymerase can only add nucleotides to the ______ end of a growing strand.

Multiple choice question.

1'

3'

5’

3

What enzyme binds to a DNA promoter region to initiate transcription?

Multiple choice question.

Primase

RNA synthase

DNA polymerase

RNA polymerase

DNA gyrase

RNA polymerase

What are the three major structures directly involved in translation?

Multiple choice question.

DNA, mRNA and tRNA

RNA polymerase, DNA polymerase and ribosomes

Ribosomes, mRNA and tRNA

mRNA, Golgi and tRNA

Ribosomes, mRNA and tRNA

The ______ strand of DNA contains the same order of nucleotides as the corresponding RNA transcript.

Multiple choice question.

plus (+)

minus (-)

plus (+)

is transcribed from a DNA template and translated during protein synthesis.

mRNA

is the process of decoding the information carried by mRNA to synthesize a protein.

translation

The ______ _____correlates a series of three nucleotides to one amino acid or a stop codon.

genetic code

The process of transcription stops when the RNA polymerase reaches a ______.

Multiple choice question.

promoter

terminator

silencer

ender

terminator

A(n_________) is the specific sequence of three nucleotides in mRNA that encode a particular amino acid or a stop signal.

codon

An RNA transcript is synthesized in the 3' to 5' direction.

True false question.

True

False

False

The genetic code is comprised of 64 different codons. Out of these, ______code a specific amino acid.

61

The process of translation requires the three major structures. What are they?

Multiple select question.

ribosomes

RNA polymerase

DNA polymerase

sRNA

tRNA

mRNA

ribosomes

tRNA

mRNA

The genetic code includes _______ stop codon(s).

Multiple choice question.

20

61

3

7

1

3

The function of mRNA is to ______.

Multiple choice question.

bring amino acids to the ribosome for transcription

serve as a template for protein synthesis

compose ribosomal subunits

serve as a template for protein synthesis

Information encoded in genetic material is translated into proteins based on rules known as the ______.

Multiple choice question.

genetic code

RNA world hypothesis

central dogma

genetic code

Several codons code for the same amino acid, which is called the redundancy of the code. Because of redundancy, the genetic code is said to be degenerate.

True false question.

True

False

True

A codon contains how many nucleotides?

Multiple choice question.

1

It depends on the size of the gene

20

3

3

An mRNA sequence has ______.

Multiple choice question.

only a single reading frame, which must be used for translation

three potential reading frames, but only one is typically used for translation

three potential reading frames, and any one can be used for translation

three potential reading frames, but only one is typically used for translation

How many codons are used to specify the 20 possible amino acids?

Multiple choice question.

64

20

30

3

61

61

Protein synthesis involves ______, which align amino acids and catalyze peptide bond formation between them.

ribosomes rRNA

The signal to end protein synthesis is indicated by sequences called .__________ ________

stop codons

In this schematic of mRNA, label A points to the_____-binding site, label B depicts the______ codon, and label C highlights the_____ codon.

ribosome, start, stop

______is transcribed from a DNA template and translated during protein synthesis.

mRNA

Which type of RNA molecule is included in the composition of ribosomal subunits?

Multiple choice question.

mRNA

rRNA

tRNA

rRNA

Why is the genetic code said to be redundant?

Multiple choice question.

More than one codon can code for a specific amino acid.

It is no longer needed by cells: DNA can be directly decoded to make protein.

The code is universal: all living things use the same genetic code.

Any amino acid can be decoded from any codon.

More than one codon can code for a specific amino acid.

The function of a tRNA is to ______.

Multiple choice question.

compose ribosomal subunits

carry the amino acids used in translation

bring a ribosome to the amino acid

carry the amino acids used in translation

What is the outcome if translation begins at the wrong reading frame?

Multiple choice question.

DNA polymerase corrects the reading frame.

Generally, a non-functional protein is made.

Redundancy in the code ensures that the same protein is always made.

Generally, a non-functional protein is made.

A tRNA has a(n) _______, a group of three nucleotides that is complementary to the codon of the mRNA.

anticodon

What are the roles of ribosomes in translation?

Multiple select question.

aligning amino acids and catalyzing the formation of peptide bonds between them

carrying information for the synthesis of a protein

Ribosomes detect sequences that indicate where translation should start and finish.

bringing amino acids to the site of protein synthesis

aligning amino acids and catalyzing the formation of peptide bonds between them

Ribosomes detect sequences that indicate where translation should start and finish.

A; amino acid

B; Hydrogen bond

C;anticodon

D; codon

In bacteria, the ribosome starts to assemble at a sequence in mRNA called the _____ _____ site. Translation begins at the first AUG codon after that.

ribosome binding

The amino acid that is placed first during translation in bacteria is _______.

Multiple choice question.

glycine

N-formylmethionine

N-formylglycine

methionine

N-formylmethionine

Each subunit of the ribosome is made up of______ and a type of RNA called_____ .

protein, ribosomal

Which type of RNA carries amino acids during protein synthesis?

Multiple choice question.

mRNA

rRNA

tRNA

tRNA

A codon and an anticodon base pair with each other because they have identical nucleotide sequences.

True false question.

True

False

False

Which of the following initiates translation?

Multiple choice question.

Amino acids are joined by peptide bonds.

Ribosomes assemble on the mRNA.

RNA polymerase binds the DNA promoter.

Ribosomes assemble on the mRNA.

A transfer RNA molecule is folded into a three dimensional shape held together by hydrogen bonds. On one end of this structure is the ______ (which binds to mRNA), and on the other end, a specific _____ _______ is attached.

anticodon

amino acid

Which of the following are true statements about events that take place during the elongation phase of translation?

Multiple select question.

Empty tRNAs leave the ribosome via the E-site.

Amino acids are joined together by the enzymes RNA polymerase.

A peptide bond is formed between amino acids on adjacent tRNAs.

tRNAs carrying amino acids occupy the A-site and the P-site of the ribosome.

Elongation starts at the promoter sequence of the DNA.

A peptide bond is formed between amino acids on adjacent tRNAs.

Empty tRNAs leave the ribosome via the E-site.

tRNAs carrying amino acids occupy the A-site and the P-site of the ribosome.

In prokaryotes, the first AUG after a ribosome-binding site typically functions as a(n) ___ codon . At other sites it simply encodes the amino acid ._____

start, met

Which of the following describes the termination of translation?

Multiple choice question.

A stop codon is reached and the polypeptide is released from the ribosome.

tRNA leaves the E-site on the ribosome.

A terminator sequence is reached and mRNA is released from the DNA template.

A stop codon is reached and the polypeptide is released from the ribosome.

Which type of RNA molecule is included in the composition of ribosomal subunits?

Multiple choice question.

mRNA

rRNA

tRNA

rRNA

The function of a tRNA is to ______.

Multiple choice question.

compose ribosomal subunits

carry the amino acids used in translation

bring a ribosome to the amino acid

carry the amino acids used in translation

Eukaryotic mRNA is first synthesized as an immature transcript called ______ ______. It has to be processed significantly before it forms mature mRNA.

pre mRNA

This figure highlights the _____ phase of translation in bacteria.

initiation

Microorganisms must adapt rapidly to changes in their environment in order to ______.

Multiple choice question.

communicate

infect

survive

die

survive

Translation terminates when the ribosome reaches a(n) ______codon, which is a codon not recognized by a tRNA.

stop

The transmission of information from outside a cell to the inside is known as ______.

Multiple choice question.

quorum sensing

signal transduction

two-component regulatory systems

antigenic variation

signal transduction

Some microorganisms can alter characteristics of certain surface proteins, allowing them to avoid detection by the host's immune system. This phenomenon is called ______.

Multiple choice question.

quorum sensing

antigenic variation

natural selection

phase variation

antigenic variation

What is the proper order of the following events in the expression of a eukaryotic gene?1. translation2. RNA processing3. transcription

Multiple choice question.

1, 3, 2

3, 1, 2

2, 3, 1

3, 2, 1

1, 2, 3

3,2,1

Enzymes that are synthesized constantly in a cell are called ._____

constitutive

All of the following are examples of means by which microorganisms can respond to changing environmental conditions EXCEPT ______.

Multiple choice question.

quorum sensing

two-component regulatory system

signal transduction

production of different ribosomes

production of different ribosomes

While standard sigma factors recognize promoters for genes that need to be expressed during routine growth conditions, alternative sigma factors ______.

Multiple choice question.

recognize different sets of promoters, thereby controlling expression of specific groups of genes

act by binding to the operator site and either blocking or promoting transcription

serve in the process of translating the mRNA into proteins

serve as backup regulators to control expression of these genes for routine growth in the absence of standard sigma factors

recognize different sets of promoters, thereby controlling expression of specific groups of genes

The lac operon only functions when ______ is present in the medium but ______ is absent from the medium.

Multiple choice question.

glucose; lactose

glucose; allolactose

lactose; maltose

lactose; glucose

lactose; glucose

Information is passed from the environment into the cell by a process known as signal _____

Transduction

Eukaryotic cells can regulate the levels of mRNA by destroying specific RNA transcripts through a process known as RNA , abbreviated ______RNAi.

interference