Chapter 6 Mastering Biology

What is the monomer of the DNA molecule?

A-Nucleotide
B-Polynucleotide
C-Monosaccharide
D-Peptide

A-Nucleotide

What do the letters D-N-A stand for?

A) Dioxyribonuclear acid
B)Deoxyrobonuclear acid
C)Deoxyribonucleic acid
D)Dioxyribonucleic acid

C)Deoxyribonucleic acid

What is different from one DNA nucleotide to the next?

The base
The phosphate group
The sugar molecule
The protein

The base

Which enzyme is responsible for adding complementary DNA bases to an exposed DNA strand?

DNA helicase
DNA polymerase
DNA ligase
DNA peptidase

DNA polymerase

DNA helicase breaks which type of bond in the DNA molecule?

Covalent bonds
Ionic bonds
Peptide bonds
Hydrogen bonds

Hydrogen bonds

According to the base pairing rules of DNA, if the sequence of bases on one strand was AGGCTTA, what would be the sequence of bases on the complementary strand?

AGGCTTA
ATTCGGA
TCCGAAT
CGGATTC

TCCGAAT

Which of the following statements is incorrect regarding DNA and RNA?

A They are found in different locations in the cell.
B DNA is double stranded, and RNA is a single strand.
C One of the bases is different.
D They each contain a slightly different sugar molecule.
E All of the above are correct.

E All of the above are correct.

If DNA directs the production of RNA, what does RNA make?

RNA makes proteins.
RNA makes membranes.
RNA makes hereditary molecules.
RNA makes more DNA

RNA makes proteins.

Why does transcription occur in the nucleus and not in the cytoplasm in eukaryotes?

A Ribosomes cannot leave the nucleus.
B DNA cannot leave the nucleus.
C RNA cannot exist in the cytoplasm.
D Codons are only found in the nucleus.

B DNA cannot leave the nucleus.

Which process results in the creation of mRNA?

A Translation
B Transcription
C Replication
D All of the above

B Transcription

What is a gene?

A) A section of DNA that codes for a portion of a protein
B) A discrete sequence of DNA nucleotides
C) A section of DNA that codes for one or more proteins
D) All of these and more are part of the expanding definition of a gene.

D) All of these and more are part of the expanding definition of a gene.

If the base sequence of template strand reads GCCATTAC, what is the base sequence of the mRNA?

A) CGGTAATG
B) GCCAUUAC
C) CGGTUUTG
D) CGGUAAUG

D) CGGUAAUG

What does "transfer RNA" actually transfer?

A) Transcripts
B) Codons
C) Ribosome
D) Amino acids

D) Amino acids

Which nucleic acid acts like an enzyme, stabilizing and orienting different molecules to facilitate the formation of bonds between them?

A) DNA
B) rRNA
C) tRNA
D) mRNA

B) rRNA

Where does translation occur in eukaryotes?

A) In the nucleus only
B) Both in the nucleus and in the cytoplasm
C) In the cytoplasm only
D) In neither the nucleus nor the cytoplasm

C) In the cytoplasm only

Alternative splicing allows the production of several different proteins from the same gene in both prokaryotes and eukaryotes.
A) TRUE
B) FALSE

B) FALSE

How many nucleotides are required to code for 10 amino acids?

A) 30
B) 10
C) 20
D) 3

A) 30

Do all cells of the body express the same genes?

A) No, since they don’t contain the same DNA
B) Yes, since they all make the same proteins
C) Yes, since they all contain the same DNA
D) No, since they don’t all need to make the same proteins

D) No, since they don’t all need to make the same proteins

What does it mean when we say a gene is "turned off"?

A) The gene is now activated.
B) The gene cannot be transcribed and translated into a protein.
C) The gene is no longer working properly.
D) The gene has a mutation.

B) The gene cannot be transcribed and translated into a protein.

Barr bodies are associated with ________.

A) proto-oncogenes
B)frameshift mutations
C)signal transduction
D) X chromosome inactivation

D) X chromosome inactivation

Your body is composed of a dazzling array of different cell types. Each cell type develops its own unique properties. How does this happen?

A) Each cell type is provided with its own specialized set of genes during cell division.
B) All cells (with very few exceptions) contain the same set of genes, but the process of gene expression determines which genes are active in each cell.
C) The zygote contains one of each of the different cell types. These ancestor cells then divide to produce the diversity of cell types in the adult.
D) none of the above

B) All cells (with very few exceptions) contain the same set of genes, but the process of gene expression determines which genes are active in each cell.

Operons are a standard method for gene regulation in _____.

A) all organisms
B) eukaryotes but not prokaryotes
C) prokaryotes but not eukaryotes
D) E. coli, but they are rare in other organisms

C) prokaryotes but not eukaryotes

Within an operon, repressors _____.

A) block gene transcription to RNA by attaching to the operator
B) block gene transcription to RNA by attaching to the promoter
C) block mRNA translation by attaching to the mRNA for a specific gene
D) block gene transcription to RNA by attaching directly to the gene itself

A) block gene transcription to RNA by attaching to the operator

To begin the process of gene transcription, RNA polymerase attaches to _____.

A) the gene that will be transcribed
B) the promoter associated with the target gene
C) the operator associated with the target gene
D) none of the above

B) the promoter associated with the target gene

The lac operon controls expression of three genes that produce lactose-digesting enzymes. What role does lactose play in regulating the lac operon?

A) It is not directly involved in gene regulation in this system.
B) It turns off the gene that produces the repressor protein, thereby allowing production of the three enzymes.
C) It binds to and disables the repressor protein, thereby allowing production of the three enzymes.
D) It binds to the promoter region of the operon, thereby allowing RNA polymerase to attach and begin transcription of the three genes.

C) It binds to and disables the repressor protein, thereby allowing production of the three enzymes.

The signal transduction pathway allows ________.

A) a cell to repair damage to its DNA
B) genes from one organism to be inserted into the nucleus of another organism’s cells
C) whole genomes to be sequenced
D) one cell to regulate the gene expression of another cell

D) one cell to regulate the gene expression of another cell

When is cell-to-cell communication particularly important in regulating gene expression?

During mitosis
During meiosis
During embryonic development
During replication

C) During embryonic development

Which genes are responsible for your overall structure, such as how many legs you have and where they develop?

Proto-oncogenes
Homeotic genes
Oncogenes
Growth factor genes

Homeotic genes

What are carcinogens?

All mutagens
Errors during DNA replication
Physical or chemical factors that can lead to mutations causing cancer
Chemical factors that can treat cancer

Physical or chemical factors that can lead to mutations

The type of mutation that alters the nucleotide sequence of a gene but does not alter the amino acid sequence of the protein produced from that gene is called ________ mutation.

frameshift
silent
missense
nonsense

silent

How does a cell typically know when to divide?

Oncogenes code for growth factor proteins that initiate cell division.
They have an internal clock and only divide when they reach a certain age.
Tumor suppressor genes code for growth factor proteins that initiate cell division.
Proto-oncogenes code for growth factor proteins that initiate cell division.

Proto-oncogenes code for growth factor proteins that initiate cell division.

Cancer is ________.

cells with proto-oncogene activated
any tumor in the body
what happens when cells get old
uncontrolled cell growth

uncontrolled cell growth

The spread of cancer cells from their site of origin to sites distant in the body is called ________.

transformation
growth
metastasis
mitosis

metastasis

What is a "benign" tumor?

A mass of cells that grows out of control but remains at the site of origin
A mass of cells that grows out of control and spreads to other tissues
A mass of cancerous cells
A single mutated cell that could potentially develop into cancer

A mass of cells that grows out of control but remains at the site of origin

What is the main cause of cancer?

Exposure to carcinogens in the environment
Old age, during which the cells of the body no longer work properly
DNA replication no longer working properly
We do not currently know the main cause of cancer.

Exposure to carcinogens in the environment

Are there ways to prevent cancer?

No, cancer cannot be prevented or treated.
Yes, there are many ways cancer can be prevented, including through a healthy diet and exercise.
Yes, cancer can be prevented, but only with intense exercise.
No, cancer cannot be prevented; it can only be treated.

Yes, there are many ways cancer can be prevented, including through a healthy diet and exercise.

Gene cloning is used to ________.

produce large quantities of human proteins
cure genetic disorders
help cure cancer
make other organisms, such as Dolly, the first cloned sheep

produce large quantities of human proteins

Why can a person who is unable to produce insulin be successfully treated with insulin derived from genetically modified bacteria?

The insulin-producing gene of bacteria was altered to have the same base sequence as the human counterpart and now produces the human version of insulin.
The gene that produces insulin in humans was inserted into the bacteria where it continues to produce human insulin.
Typical bacterial insulin is exactly the same as human insulin.
Bacterial insulin is similar enough to human insulin to serve the same purpose.

The gene that produces insulin in humans was inserted into the bacteria where it continues to produce human insulin.

The small circular molecules of DNA commonly found in bacteria are called ________.

chromatids
chromophores
plasmids
plastids

plasmids

What is recombinant DNA?

DNA that can no longer replicate
DNA that is circular
DNA that comes from plasmids
A segment of DNA containing sequences from two different sources

A segment of DNA containing sequences from two different sources

A collection of cloned DNA fragments representing the organism’s entire genome is called a ________.

genomic library
complementary DNA collection
clonal anthology
transgenic assembly

genomic library

What is the name of the enzyme that builds cDNA out of mRNA?

RNA polymerase
DNA polymerase
DNA helicase
Reverse transcriptase

Reverse transcriptase

Genetically modified organisms that acquire genes from a different species are called ________ organisms.

synthetic
cloned
mutant
transgenic

transgenic

A cloned mammal is made by removing the DNA from the unfertilized egg of an egg donor, replacing it with DNA from a cell of a mature animal, and then implanting that cell into the uterus of a surrogate mother. The cell then divides and behaves as if it were a regular embryo. Answer the following question(s) regarding a clone.

Will the clone typically be sterile or fertile?

Sterile
Fertile
It depends on whether it is male or female.

Fertile

Three of the following statements are correct. Identify the statement that is not correct regarding genetically modified organisms.

There are no risks associated with GM crops.
GM crops have been produced with increased nutrition.
GM crops have been produced that are disease resistant.
GM animals are not in our food supply.

There are no risks associated with GM crops.

What separates the strands of DNA in the polymerase chain reaction (PCR) technique?

Restriction enzymes
Helicase
Heat
Centrifuge

Heat

The PCR technique doubles the amount of DNA in a sample in each cycle. If you started the PCR technique with two fragments of double-stranded DNA, calculate how many double-stranded DNA fragments you would you have after four cycles.

32
64
8
16

32

What is the role of primers in the PCR techniques?

To target specific areas of DNA
To add free nucleotides to the newly formed DNA molecule
To allow single strands of DNA to bind together
To separate strands of double-stranded DNA

To target specific areas of DNA

Gel electrophoresis separates DNA fragments according to their ________.

polarity
charge
length
base sequences

length

DNA profiling relies on an individual’s ________, no two of which are the same between different people, except identical twins.

unique fingerprints
unique set of short tandem repeats within DNA
unique set of genes
unique mRNA sequences

unique set of short tandem

Is most of our DNA made up of genes?

Yes, the vast majority of human DNA consists of genes.
No, genes make up only 1.5% of our DNA.

No, genes make up only 1.5% of our DNA.

How does a scientist get the corrected version of a gene into the cells of a gene therapy patient?

By attaching it to the surface of microscopic beads, it is then shot into the individual (i.e., shotgun method).
It is directly injected with a microscopic hypodermic needle.
It is delivered with a modified virus.
By attaching it to a food molecule, like glucose, it is then ingested by the individual.

It is delivered with a modified virus.