Deck 10: Mutations and Cancer Fighting Fate

Question 1

List three types of genetic mutations that may occur.

Answer 1

Mutations can arise from 1)extra nucleotides being inserted into a gene,
2)nucleotides being deleted from a gene,or 3)nucleotides being changed.

Question 2

There are several different alleles for flower color in carnations.One of them causes white flowers; a different allele of the same gene causes red flowers.This means that all of the following are true,EXCEPT

A) white carnations have different DNA sequences than red carnations.
B) white carnations and red carnations have somewhat different proteins.
C) a carnation plant could have one copy of the white allele and one copy of the red allele.
D) a carnation plant could have two copies of the white allele and two copies of the red allele.
E) All of the above.

Answer 2

a carnation plant could have two copies of the white allele and two copies of the red allele.

Question 3

Gene mutations can arise when nucleotides are

A) added to the gene.
B) taken away from the gene.
C) changed within the gene.
D) mismatched within the gene.
E) All of the above.

Answer 3

All of the above.

Question 4

There are approximately __________ different alleles for the BRCA1 gene.

A) 10
B) 100
C) 300
D) 600
E) 1000

Question 5

Alleles are located

A) on chromosome 17 only.
B) in random locations on chromosomes.
C) at a specific position on each of a pair of chromosomes.
D) on one chromosome of each pair.
E) on chromosomes 13 and 17.

Question 6

Most new alleles arise via

A) large rearrangements of genes.
B) exchanges of genes during crossing over.
C) mutations in existing genes.
D) changes in DNA polymerase that alter how polymerase copies DNA.
E) changes in the beginning and ending of a gene.

Question 7

A newly identified mutation in mice,called "darkened dorsal," causes a dark stripe along the mouse's back.This mutation is located at a specific location on chromosome 2.A different sequence at this same chromosomal position results in a fur color pattern called "nonagouti." Based on this information,darkened dorsal and nonagouti are different

A) genes for fur color.
B) alleles for the same gene.
C) mutations of the same chromosome.
D) chromatids.
E) All of the above.

Question 8

How many copies of any particular gene does an individual human have?

A) 4
B) 1
C) 2
D) 46
E) 23

Question 9

What would be the best way to distinguish between two alleles and two genes?

A) Examine the proteins they produce; most genes would produce very similar versions of the same protein, but two alleles would produce very different proteins.
B) Examine the proteins they produce; a gene produces one protein, and an allele produces two different proteins.
C) Examine their DNA; the DNA sequences of two different alleles would be more similar to each other than the sequences of two different genes.
D) You can't distinguish between them; there's no actual difference between alleles and genes.
E) Determine their chromosomal location; alleles will always be on different chromosomes, but genes will always be on different copies of the same chromosome.

Question 10

What is an example of a mutation in an allele?

A) a base change in the gene coding sequence
B) a base change in the gene's regulatory regions
C) a deletion of a base within the gene
D) an insertion of a base within the gene
E) All of the above.

Question 11

Which of the following is TRUE?

A) Alleles are usually harmful because they result from mutations.
B) Alleles are just different versions of the same gene.
C) Normal, healthy individuals don't usually carry alleles.
D) An individual may have one, two, or three alleles for a particular trait.
E) None of the above.

Question 12

Different alleles are the result of

A) mutations in RNA sequences.
B) any change in DNA sequences.
C) changes in DNA sequence within a gene.
D) changes in the size of a chromosome.
E) any kind of radiation damage.

Question 13

When copying DNA,DNA polymerase makes a mistake about every 10,000 to 100,000 nucleotides.Most of these mistakes,however,are corrected by repair enzymes so that mutations occur in only

A) 1 in 500,000 nucleotides.
B) 1 in 1 million nucleotides.
C) 1 in 10 million nucleotides.
D) 1 in 100 million nucleotides.
E) 1 in 1 billion nucleotides.

Question 14

An allele is

A) any section of DNA.
B) a gene.
C) a specific section of a chromosome.
D) an alternate version of a gene.
E) a pair of genes.

Question 15

A mutation is best described as an error in

A) DNA.
B) mRNA.
C) protein.
D) enzymes.
E) cell division.

Question 16

Different versions of a gene are called alleles; a mutation in a gene can create an allele.

Question 17

How many different alleles of a gene like BRCA1 can an individual have?

A) Several hundred, since there are hundreds of known BRCA1 alleles
B) Four: two from their father and two from their mother
C) Only two: one from their father and one from their mother
D) One for males and hundreds for females
E) One for males and two for females

Question 18

How many alleles for a single trait are present in each human cell?

A) 1
B) 2
C) 23
D) 46
E) 4

Question 19

Mutations in a gene can lead to the development of new ______ for the gene.

Question 20

Bob and Linda are a newly married couple.They hope to have a child but are having trouble getting pregnant.They visit a fertility clinic,where they receive a variety of tests.One test shows that Bob is healthy but carries a single disease-causing allele for CFTR (the gene that can cause cystic fibrosis),but Linda does not.This means that

A) Bob's DNA sequence for CFTR is different from Linda's.
B) Bob has two different versions of the CFTR gene.
C) Linda does not have any copies of the CFTR gene.
D) Bob is unable to ever have children.
E) Both A and B

Question 21

Why might a change in its amino acid sequence lead to a change in the way a protein functions?

A) Amino acids determine a protein's shape. The wrong shape may not function normally.
B) A change in the amino acid sequence would not change the final protein.
C) A change in the amino acid sequence would cause a change in the DNA, which alters the protein.
D) A change in the amino acid sequence causes the DNA to pair incorrectly.
E) None of the above.

Question 22

Amino acid sequences result from the process of

A) transcription.
B) translation.
C) replication.
D) regulation.
E) complementary base pairing.

Question 23

Do all mutations that occur within the DNA sequence result in abnormal protein expression,and therefore affect the function of the protein?

A) Yes, regardless of the location of the mutation, protein expression and function will be adversely affected.
B) No, mutations occurring within the noncoding regions of the DNA sequence will not affect overall protein structure
C) No, DNA repair enzymes are designed specifically to "proofread" the DNA and they catch most mistakes
D) Yes, any mutations located within the DNA sequence will affect the structure of the protein.
E) B and C

Question 24

Why should pregnant women never be given X-rays?

Question 25

The number of errors made by DNA polymerase during DNA replication that pass though the cell's repair checkpoints is estimated at

A) 1 in 100 bases mismatched.
B) 1 in 1000 bases mismatched.
C) 1 in 1,000,000 bases mismatched.
D) 1 in 1,000,000,000 bases mismatched.
E) 1 in 10 bases mismatched.

Question 26

Which of the following cannot lead to a mutation?

A) replacing thymine with uracil when making RNA
B) deleting a portion of a gene
C) replacing thymine with guanine when copying DNA
D) inserting three base pairs into a gene
E) inserting one base pair into a gene

Question 27

Doctors will screen individuals with a strong family history of breast cancer for mutations in the BRCA1 gene.Explain why someone who does not test positive for a mutation can still be at risk for a BRCA1 mutation and breast cancer.

Question 28

Mutations in DNA sequences may occur during the process of

A) transcription.
B) translation.
C) replication.
D) tumor suppression.
E) apoptosis.

Question 29

DNA damage is usually repaired

A) in the egg or sperm cells before fertilization.
B) at or before checkpoints in the cell cycle.
C) in the ribosome during translation.
D) by the mitotic spindle.
E) by the complementary strand of DNA.

Question 30

What would happen if the enzyme that makes DNA added a nucleotide to the middle of a coding region of a gene?

A) It would change the reading frame of the DNA and possibly lead to a change in the amino acid sequence of the protein made from that gene.
B) It wouldn't matter because it is in a coding region.
C) It is only one nucleotide so it wouldn't matter; more than one nucleotide would need to be added to change a protein.
D) It would make longer mRNA and protein from that gene.
E) All of the above.

Question 31

How often do mistakes occur when copying DNA? Do all these mistakes appear in the final,copied DNA?

Question 32

Mutations are

A) always harmful.
B) never neutral.
C) always helpful.
D) never helpful.
E) sometimes harmful, sometimes helpful, and sometimes neutral.

Question 33

Radioactive Man,a comic-book superhero,gained his abilities by falling into a vat of industrial toxic waste.Is this a likely outcome?

A) Yes, because mutations can be helpful, harmful, or neutral.
B) No, because most mutations are either harmful or neutral.
C) No, because toxic waste is not mutagenic.
D) No, because so many mutations would probably cause cancer or other disease.
E) Both B and D

Question 34

Which sequence is the complementary DNA sequence of ATG GGC CTG?

A) ATG GGC CTG
B) TAC CCG GAG
C) TUC CCG GUC
D) TAC CCG GAC
E) TAC CCC GAC

Question 35

The enzyme that copies DNA makes a mistake approximately every 10,000 to 100,000 bases.Surprisingly,however,if we examine newly copied DNA,we see that the actual error rate is lower than this.How is that possible?

A) The bases are self-correcting; the DNA will fix any errors as it is copied.
B) The cell is immediately killed if it contains a mistake in its DNA.
C) There are other enzymes that find errors in DNA and repair them.
D) All of the above.
E) None of the above.

Question 36

A mutation would most likely be inherited if it is located in a ____ cell.

A) skin
B) body
C) sperm
D) liver
E) All of the above.

Question 37

Substitution of a nucleotide base in the coding sequence of a gene may alter the protein's

A) amino acid sequence.
B) 3D shape.
C) folding.
D) function.
E) All of the above.

Question 38

Why aren't all mutations that occur in DNA inherited by our offspring?

A) Only mutations in the DNA contained in the sperm and eggs will be inherited.
B) Each cell has different DNA in it, with only the genes that cell needs.
C) DNA that is mutated can't be inherited; the cell corrects it before passing it on.
D) DNA that is inherited can't have more than one mutation in it.
E) Some mutations occur in noncoding regions of genes, so they are not inherited.

Question 39

Which sequence is a result of a single mismatch in DNA replication of the sequence ATG GGC CTG?

A) ATG GGC CTC
B) AAG GGC CTC
C) TAC CCG GTC
D) TGC CCG GAG
E) TUC CCG GUC

Question 40

DNA mutations can

A) be detrimental.
B) be beneficial.
C) have no effect.
D) All of the above.
E) A or B only

Question 41

Not all mutations are dangerous.Why?

A) Many mutations occur in noncoding regions.
B) Some mutations can have no effect on proteins.
C) Many DNA mutations are corrected by enzymes
D) Some cells don't use all their genes.
E) All of the above.

Question 42

Is the way a protein folds important for its function?

A) Yes, protein function depends on the protein's 3-D structure.
B) Yes, because DNA mutations are caused by protein folding incorrectly.
C) No, as long as the sequence is correct.
D) No, as long as the protein is still soluble.
E) None of the above.

Question 43

Which of the following is NOT a known carcinogen?

A) ultraviolet light
B) alcohol
C) charred food
D) smoking
E) None of the above; all are known carcinogens

Question 44

Which type of mutation do you think is most harmful to a cell,a base substitution (e.g.,an A is replaced by a G)or a base insertion (e.g.,ACG becomes ACTG)? Why?

Question 45

Which of the following statements is always TRUE?

A) A mutation is harmful.
B) Mutations lead to changes in protein function.
C) Changes in DNA lead to changes in protein function.
D) A change in the DNA may change a protein's shape and function.
E) A change in DNA will lead to cancer.

Question 46

If you consider most of the mutations that occur in your DNA,the majority have ______ effects.

A) few or no
B) helpful
C) harmful
D) reversible
E) lethal

Question 47

Mutations usually affect a protein's

A) size.
B) shape.
C) length.
D) electrical charge.
E) longevity.

Question 48

Why are Ashkenazi Jews more susceptible to certain hereditary diseases?

A) They have inherited predispositions and carcinogen exposure.
B) They have increased occupational exposure and environmental insults.
C) They are predisposed by exposure to occupational risks.
D) They have an increased carrier rate for these diseases from their ancestors.
E) They all have increased errors in DNA proofreading.

Question 49

Mutations in DNA occur during

A) transcription.
B) translation.
C) protein modification.
D) RNA duplication.
E) DNA duplication.

Question 50

What is the difference between a somatic cell mutation and a germ-line mutation?

A) Only mutations in germ-line cells can be passed on to offspring.
B) Only mutations in somatic cells can be passed on to offspring.
C) Somatic cell mutations cannot lead to cancer, but germ-line mutations can.
D) Germ-line mutations do not involve DNA, but somatic cell mutations do.
E) Somatic cell mutations do not involve DNA, but germ-line mutations do.

Question 51

The Ashkenazi Jews have a higher rate of mutated alleles than the general public.All of the following are possible reasons for this,EXCEPT

A) in their Middle Eastern homeland, intense sunlight led to increased mutations.
B) they are descendants of a small number of individuals.
C) their population expanded and contracted.
D) members usually marry others within the same group.
E) new alleles were not introduced through intermarriage with other groups.

Question 52

Which of the following is NOT a known source of mutations?

A) DNA repair or replication errors
B) chemical or environmental exposure
C) heredity
D) insufficient sleep and poor diet
E) None of the above; all are known sources of mutations

Question 53

If a person is a carrier for a disease; he or she has

A) one normal and one defective disease allele and is affected by the disease.
B) two defective disease alleles and is unaffected by the disease.
C) one normal and one defective disease allele and is unaffected by the disease.
D) two defective disease alleles and is affected by the disease.
E) two normal disease alleles and is affected by the disease.

Question 54

Which of the following is a mutagen?

A) UV light
B) smoking
C) blackened meats
D) excessive drinking
E) All of the above.

Question 55

If a mutation alters a protein,which of the following is NOT a likely outcome of the mutation?

A) The shape of the protein may be different.
B) The protein may function differently.
C) The protein may cause a disease or illness.
D) The protein may not function at all.
E) The protein may be repaired by enzymes.

Question 56

How can a person acquire mutations in their DNA?

A) inheritance
B) carcinogens
C) replication errors
D) mutagens
E) All of the above.

Question 57

How can changing the DNA sequence change a protein's function?

Question 58

How does a mutation in a noncoding region of DNA affect the final shape of the protein?

A) A mutation in a noncoding region would not affect the final protein shape, but it could affect gene regulation.
B) A change in the noncoding region leads to a change in amino acid sequence, which changes the way the protein folds.
C) A change in the amino acid sequence causes the DNA to pair incorrectly.
D) A change in the noncoding region causes the protein to fold "inside out."
E) None of the above.

Question 59

Inherited mutations

A) predispose individuals to cancer.
B) come from DNA sequence mistakes contained in germ cells.
C) can come from one's mother or father.
D) are errors in DNA that go uncorrected.
E) All of the above.

Question 60

If you avoid dangerous chemicals and radiation for your entire life,you prevent all mutations in your DNA.

Question 61

What is a mutagen?

Question 62

Explain how alterations of the BRCA proteins could lead to cancer.

Question 63

Which of the following are mutagens?

A) sunlight
B) cigarette smoke
C) alcohol
D) blackened meat
E) All of the above.

Question 64

Which of the following types of mutations is LEAST likely to lead to cancer?

A) a mutation of proto-oncogenes
B) a mutation of tumor suppressor genes
C) a mutation of a gene that codes for DNA polymerase
D) a mutation of a gene that codes for DNA repair enzymes
E) a mutation in a noncoding sequence of a gene

Question 65

All of the following are TRUE of BRCA genes,EXCEPT

A) there are two genes, and a mutation in either can lead to cancer.
B) when mutated, they produce proteins that are unable to regulate the cell cycle.
C) just one mutated BRCA gene increases a woman's lifetime cancer risk to greater than 90%.
D) mutations in BRCA genes can lead to either breast or ovarian cancer in women.
E) mutations in BRCA genes can lead to prostate cancer in men.

Question 66

A gene found in a somatic cell is mutated.The resulting protein regulates mitosis but now has a different 3D shape.What is a likely result?

A) germ-line mutations
B) hereditary mutations
C) cancer
D) down syndrome
E) cystic fibrosis

Question 67

All of the following are TRUE of breast cancer,EXCEPT

A) it is the second-most common form of cancer in women.
B) mutations in the BRCA genes affect only the breasts and ovaries.
C) BRCA mutations cause only about 50% of all hereditary breast cancers.
D) it affects about 200,000 women in the United States per year.
E) a woman may pass the predisposition for breast cancer to her children.

Question 68

A normal BRCA1 allele produces normal protein that

A) inhibits transcription.
B) inhibits translation.
C) ensures correct, error-free DNA transcription.
D) allows cells to repair DNA damage.
E) recognizes and destroys incorrectly translated proteins.

Question 69

Which of the following would most likely increase an individual's risk of cancer?

A) a mutation in the noncoding region of DNA
B) a mutation in their mother's somatic cells
C) a mutation in a gene for a DNA repairing enzyme
D) an error in transcribing DNA into RNA
E) All of the above.

Question 70

For a mutation to become an allele it must occur in one of three possible locations.What are those three?

Question 71

Which of the following will lead to a new,inheritable allele?

A) a mutation in a sperm cell
B) a mutation in an egg cell
C) a mutation in an embryo
D) a mutation in the brain
E) All of the above. except D

Question 72

Which combination(s)of mutated genes would be most likely to make a cell cancerous?

A) one oncogene
B) one tumor suppressor gene
C) two oncogenes
D) two oncogenes and two tumor-suppressor genes
E) All of the above.

Question 73

To get cancer,all you need is a mutation in one essential gene.

Question 74

The most common cancer among women is

A) prostate cancer.
B) breast cancer.
C) ovarian cancer.
D) nonmelanoma skin cancer.
E) lung cancer.

Question 75

In a cell with the following mutations,which would you expect to be MOST likely to cause tumors?

A) BRCA1 and BRCA2
B) BRCA1 and p53 mutation
C) BRCA1, BRCA2, Her2, and p53 mutations
D) BRCA1, BRCA2, and p53 mutations
E) BRCA1, Her2, and p53 mutations

Question 76

Even though DNA repair enzymes correct most errors,approximately 1 in every one billion nucleotides still contains an error.The human genome,however,is 3 billion bases long.In an average adult,there are 50 trillion to 100 trillion cells,all of which contain these 3 billion bases,and these trillions of cells divide all the time.Given all this,why do you think people don't have cancer more often?

Question 77

A woman with normal BRCA alleles has a child with a man who has one mutated BRCA1 allele.What is the probability that the child will have a mutated BRCA1 allele?

A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Question 78

What is the number-one preventable cause of cancer?

A) smoking
B) UV light exposure
C) grilled meats and vegetables
D) pollution exposure
E) alcohol

Question 79

What are the three main ways a person can acquire a mutation in their DNA?

Question 80

In a cell with the following mutations,which would you expect to be LEAST likely?

A) BRCA1 and BRCA2
B) BRCA1
C) BRCA1, BRCA2, Her2, and p53 mutations
D) BRCA1, BRCA2, and p53 mutations
E) BRCA1, Her2, and p53 mutation