Exam 5

Question 1

50% chance of passing the trait to each child (male or female). Unaffected relatives or siblings do not transmit the disorder, and age of onset is delayed.

Answer 1

Autosomal dominant trait

Question 2

All children of an affect parents are carriers, with early age onset. Unaffected siblings may be carriers with 25% chance of an affected child and noncarrier child and 50% carrier child.

Answer 2

Autosomal recessive trait

Question 3

Likelihood that a clinical condition will occur when a particular genotype is present (complete or incomplete)

Answer 3

penetrance

Question 4

What are the two genetic variants using substitutions?

Answer 4

Missense- incorrect amino acid
Nonsense- replace amino acid with stop codon

Question 5

What are the two genetic variants using frameshift?

Answer 5

insertions and deletions

Question 6

What type of trait disorder is FH?

Answer 6

autosomal dominant LOF

Question 7

What type of trait disorder is osteogenesis imperfecta?

Answer 7

autosomal dominant LOF

Question 8

What type of trait disorder is PCSK9’s affect on LDL-R?

Answer 8

autosomal dominant GOF

Question 9

What type of trait disorder is cystic fibrosis?

Answer 9

autosomal recessive LOF

Question 10

50% chance of passing the gene to their sons and daughters, however only males are affected

Answer 10

X-linked recessive

Question 11

A. Autosomal dominant
B. Autosomal recessive
C. X-linked Recessive
D. Mitochondrial

Answer 11

A.

Question 12

A. Autosomal dominant
B. Autosomal recessive
C. X-linked Recessive
D. Mitochondrial

Answer 12

B.

Question 13

A. Autosomal dominant
B. Autosomal recessive
C. X-linked Recessive
D. Mitochondrial

Answer 13

C.

Question 14

A. Autosomal dominant
B. Autosomal recessive
C. X-linked Recessive
D. Mitochondrial

Answer 14

D.

Question 15

State whether the neurodegenerative triplet repeat mutation is dominant or recessive:
Huntington
Fragile X
Freidreich ataxia

Answer 15

Huntington- Dom
Fragile X- Dom
Freidreich ataxia- Recessive

Question 16

Mutation where females affected will transmit to 100% of children. Males do not pass down trait but can be affected.

Answer 16

Mitochondrial

Question 17

Disorder characterized by a change in autosome number and are more sever than single gene disorders

Answer 17

cytogenetic disorders

Question 18

In what parts of meiosis can chromosome nondisjunction occur?

Answer 18

Meiosis I and II

Question 18

In what parts of meiosis can chromosome nondisjunction occur?

Answer 18

Meiosis I and II

Question 19

Cytogenetic condition with an increase in chromosome number

Answer 19

down syndrome

Question 20

Cytogenetic condition with an decrease in chromosome number

Answer 20

Turner Syndrome

Question 21

What type of inheritance pattern is involved in genetic imprinting?

Answer 21

Complex inheritance patterns

Question 22

What type of inheritance pattern is involved in genomic imprinting?

Answer 22

Complex inheritance patterns

Question 23

Genetic condition where some regions of DNA are turned off (inactivated) in the copy received from the mother or the father

Answer 23

Genomic imprinting

Question 24

When discussing human genetic studies, the preferred term to describe a permanent change in the sequence of a gene is:
A. Variant
B. Mutation
C. Modification
D. Polymorphism

Answer 24

A. Variant

Question 25

Silent mutations:
a. Are the most common genetic cause of deafness in Caucasians
b. Are also known as balanced translocations since they do not result in loss genetic material or changes in the DNA sequence
c. Can change the amino acid sequence of a protein if they occur in the first position of a codon
d. Are most likely a benign change to the DNA sequence

Answer 25

d. Are most likely a benign change to the DNA sequence

Question 26

Down Syndrome is most commonly caused by:
a. Ring chromosome 14
b. X chromosome monosomy
c. Y chromosome monosomy
d. Chromosome 21 trisomy

Answer 26

d. Chromosome 21 trisomy

Question 27

True/False: Penetrance refers to the percentage of people who have a disease-causing mutation that show traits associated with this change

Answer 27

True

Question 28

Which of the following is an example of variable expressivity?
a. One male child of a mother who carries the mutation for Hemophilia A has the trait, but a second male child does not
b. One male child of a father who has a mutation in the gene encoding the LDL receptor has familial hypercholesterolemia, but a second male child does not
c. A male child of a mother who carries the mutation for Hemophilia A has the trait, but a female child does not
d. One male child of a father who has a mutation in the gene encoding the collagen a1 subunit has hearing loss, but a second male child has normal hearing but suffered ten bone fractures

Answer 28

d. One male child of a father who has a mutation in the gene encoding the collagen a1 subunit has hearing loss, but a second male child has normal hearing but suffered ten bone fractures

Question 29

Which of the following mainly affect males?
a) A dominant gain-of-function mutation in a gene located on chromosome 7
b) A dominant negative mutation in a gene located on chromosome 20
c) A recessive loss-of-function mutation in a gene located on chromosome 2
d) A recessive mutation on the X chromosome
e) A dominant loss-of-function mutation in a gene located on chromosome 7

Answer 29

d) A recessive mutation on the X chromosome

Question 30

The mutation that likely leads to frameshift:
a) Changing C to G in the codon TGC, resulting in a change of the coded amino acid from cysteine to tryptophan
b) Changing C to T in the codon TGC, resulting in no change in the coded amino acid
c) Changing C to A in the codon TGC, resulting in a change of the coded amino acid from cysteine to stop
d) Inserting a C before the codon TGC, resulting in a change of the coded amino acid from cysteine to leucine

Answer 30

d) Inserting a C before the codon TGC, resulting in a change of the coded amino acid from cysteine to leucine

Question 31

Huntington’s disease is a genetically inherited neurodegenerative disease. Patients often have more than 40 CAG repeats in one of the exons in the huntingtin gene. Which of the following is the most likely outcome?
a) A decrease in the huntingtin gene transcription
b) An increase in the huntingtin gene translation
c) A change in the huntingtin protein structure and function
d) A change in the stability of the huntingtin mRNA

Answer 31

c) A change in the huntingtin protein structure and function

Question 32

Cancer cells are (more/less) differentiated and (poorly/well) demarcated and differentiated.

Answer 32

Cancer cells are less differentiated and poorly demarcated and differentiated.

Question 33

Estimate of aggressiveness or level of malignancy based on microscopic examination of tumor cell morphology; qualitative nature

Answer 33

Grading

Question 34

Estimate of aggressiveness or level of malignancy based on size of the primary lesion, extent of spread, and presence or absence of metastases; quantitative nature

Answer 34

Staging

Question 35

Genes that encode proteins that promote cancer

Answer 35

oncogenes

Question 36

Genes that encode proteins that inhibit cancer

Answer 36

tumor suppressor genes

Question 37

Type of childhood cancer that results from a single, recessive, inherited genetic mutation. It is the result of mutation or deletion of a single gene.

Answer 37

Retinoblastoma

Question 38

Tumor suppressors are (dominant/recessive) and need (heterozygous/homozygous) deletion/mutation for both alleles.

Answer 38

Tumor suppressors are recessive and need homozygous deletion/mutation for both alleles.

Question 39

Protein that results as a chromosomal translocation (oncogene). It produces a hyperactive kinase that drives proliferation in leukemia.

Answer 39

BCR-ABL

Question 40

Which of the following statements about tumor suppressor genes is TRUE?
A) Tumor suppressor genes cause cancer.
B) The normal functioning of tumor suppressor genes prevents cancer.
C) Mutations in tumor suppressor genes never lead to cancer.
D) Duplications in tumor suppressor genes are common in cancer

Answer 40

B) The normal functioning of tumor suppressor genes prevents cancer.

Question 41

Theory that LOF mutations in both alleles of these genes are typically required for tumor formation

Answer 41

Two-hit hypothesis

Question 42

Repair of double stranded DNA breaks; inherited mutations lead to breast and ovarian cancer
A. BRCA 1/2
B. BLM
C. ATM
D. TP53

Answer 42

A. BRCA 1/2

Question 43

Inherited mutations lead to many different cancers; Li-Fraumeni syndrome
A. MLH1
B. XP
C. TP53
D. PMS2

Answer 43

C. TP53

Question 44

Syndrome caused by germ-line mutations (DNA mismatch repair genes)
A. MLH1
B. HNPCC
C. TP53
D. PMS2

Answer 44

B. HNPCC

Question 45

Extreme sensitivity to UV; mutations involve NER (nucleotide excision repair)
A. ATM
B. TP53
C. BLM
D. XP

Answer 45

D. XP

Question 46

Mutation in repairing double stranded DNA breaks; neurodegenerative disorder with increased lymphoma and leukemia incidence (ataxia telangiectasia)
A. ATM
B. TP53
C. BLM
D. XP

Answer 46

A. ATM

Question 47

Mutation in DNA helicase involved in DNA replication/repair/recombo. Rash and high likelihood of many cancers; Bloom syndrome
A. ATM
B. TP53
C. BLM
D. XP

Answer 47

C. BLM

Question 48

The critical time point when cells decide whether or not to enter the cell cycle

Answer 48

R point

Question 49

The major role of G1/S checkpoint in cell cycle is to:
A) Check whether synthesis of DNA is complete
B) Check for sufficient nutrients and building blocks for replication
C) Check whether chromosomes are attached to spindles
D) All of the above

Answer 49

B) Check for sufficient nutrients and building blocks for replication

Question 50

Which signaling leads to cell proliferation:
A. MAP kinase
B. JAK/STAT
C. P13K/AKT1
D. A and C
E. All of the above

Answer 50

E. All of the above

Question 51

Which activate cancer? (O) Tumor suppressor? (TS)
RAS
P13K
AKT
PIP2
BRAF
TSC
ERK
mTOR
PTEN
PIP3
MEK

Answer 51

RAS (O)
P13K (O)
AKT (O)
PIP2 (TS)
BRAF (O)
TSC (TS)
ERK (O)
mTOR (TS)
PTEN (TS)
PIP3 (O)
MEK (O)

Question 52

Tyrosine signaling pathway

Answer 52

See image

Question 53

Match as growth inhibitor (GI), growth factor (GF), or CDK:
EGF
p16
p53
TGF-Beta
PDGF

Answer 53

EGF (GF)
p16 (CDK)
p53 (GI)
TGF-Beta (GI)
PDGF (GF)

Question 54

What is the pathway between S and G1 that leads to transcriptional activation/block?

Answer 54

Note: GI stimulates CDK inactivating cyclins
GF activate cyclins that then turn hypo RB to hyper RB

Question 55

What three genes if given a loss of function lead to disruption of apoptosis?

Answer 55

loss of: p53, p21, and BAX

Question 56

Tumor cells produce ______ to promote angiogenesis
A. EGFR
B. VEGF
C. TGF
D. VHL

Answer 56

B. VEGF

Question 57

Inherited ______ deletions increase incidence of kidney cancer
A. EGFR
B. VEGF
C. TGF
D. VHL

Answer 57

D. VHL

Question 58

Nonsense mutation refers to:

A. A single base substitution that changes an amino acid to another amino acid in the same category in terms of charge, hydrophobicity and polarity.
B. A single base substitution that does not change the coded amino acid.
C. A single base substitution that causes termination of protein translation.
D. Insertion of a single nucleotide that causes a stop codon
E. Deletion of a single nucleotide that causes a stop codon

Answer 58

C. A single base substitution that causes termination of protein translation.

Question 59

Which of the following mutations may lead to frameshift?

A. A single base substitution that changes an amino acid to another amino acid in the same category in terms of charge, hydrophobicity and polarity.
B. A single base substitution that changes an amino acid to another amino acid in a different category in terms of charge, hydrophobicity and polarity.
C. Insertion of two nucleotides
D. Trinucleotide repeat mutations
E. All of the above

Answer 59

C. Insertion of two nucleotides

Question 60

The major cause of aneuploidy is:

A. Amplification of one or more chromosomes.
B. Defect in cell mitosis.
C. Fragmentation of chromosomes.
D. Nondisjunction of a homologous pair of chromosomes at the first or second meiotic division.
E. All of the above

Answer 60

D. Nondisjunction of a homologous pair of chromosomes at the first or second meiotic division.

Question 61

Huntington disease is a genetically inherited neurodegenerative disease. Patients often have more than 40 CAG repeats in one of the exons in the huntingtin gene. These CAG repeats likely cause:

A. An increase in the huntingtin gene transcription.
B. An increase in the huntingtin gene translation.
C. Alteration of the Huntingtin protein structure and function.
D. An increase in the Huntingtin mRNA degradation.
E. An increase in the Huntingtin mRNA stability.

Answer 61

C. Alteration of the Huntingtin protein structure and function.

Question 62

Patient with a gain-of-function mutation in one copy of the gene
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 62

A. Autosome dominant disorder

Question 63

Patient with a three-fold more protein product caused by a mutation in one copy of the gene
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 63

A. Autosome dominant disorder

Question 64

Both sons and daughters could be affected.
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 64

D. A and B

Question 65

All children (100%) of an affected parent are carriers
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 65

B. Autosome recessive disorder

Question 66

The altered gene product (protein) can antagonize the function of the wild-type proteins
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 66

A. Autosome dominant disorder

Question 67

One of the patient’s parents must also be a patient
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 67

A. Autosome dominant disorder

Question 68

Mutations that often affect structural proteins
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 68

A. Autosome dominant disorder

Question 69

Mutations that often affect enzymes
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 69

B. Autosome recessive disorder

Question 70

Daughters are rarely affected
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 70

C. X-linked recessive disorder

Question 71

Female carriers have a 50% of chance of passing the gene to their sons and daughters
A. Autosome dominant disorder
B. Autosome recessive disorder
C. X-linked recessive disorder
D. A and B
E. B and C

Answer 71

C. X-linked recessive disorder

Question 72

Jennifer was born normal 9 months ago, and her parents and three other siblings (two brothers and one sister) are healthy. However, she appears to have a slow development compared to normal growth of infants. Her parents contacted her pediatrician last week, and the blood examination revealed that Jennifer has an abnormally high level of plasma phenylalanine. The doctor asked the parents, and found that one of Jennifer’s uncles (father side) is suffering from phenylketonuria (high concentration of phenylalanine in urine), a disease that is caused by mutations in phenylalanine hydroxylase, an enzyme that catalyzes the rate-limiting step in the phenylalanine catabolism. Based on this information, it is likely that phenylketonuria is:

A. An autosomal dominant disorder.
B. An autosomal recessive disorder.
C. An X-linked recessive disorder
D. An X-linked dominant disorder
E. None of the above

Answer 72

B. An autosomal recessive disorder.

Question 73

Genomic imprinting defects refer to:

A. Epigenetic inactivation of a maternal or paternal homologous gene.
B. Epigenetic inactivation of a pair of homologous genes.
C. Deletion of a pair of homologous genes.
D. B and C.
E. A, B and C.

Answer 73

A. Epigenetic inactivation of a maternal or paternal homologous gene.

Question 74

Compared with benign tumors, which of the following is NOT the characteristic of malignant tumors?

A. Malignant tumors grow more rapidly.
B. Malignant tumors are more invasive.
C. Malignant tumors are poorly differentiated.
D. Malignant tumors tend to metastasize to distant organs.
E. Malignant tumors are bigger.

Answer 74

E. Malignant tumors are bigger.

Question 75

In order to metastasize to distant organs, cancer cells must express:

A. Enzymes to break down the surrounding ECM and gain access to blood circulation.
B. Proteins that can kill immune cells.
C. p53 that can induce apoptosis of fibroblasts in ECM.
D. VEGF to form new blood vessels to deliver cancer cells to blood circulation.
E. Ligands that bind to kinase receptors.

Answer 75

A. Enzymes to break down the surrounding ECM and gain access to blood circulation.

Question 76

Which of the following may NOT lead to cancer development?

A. Gain-of-function mutations in Ras.
B. Amplification of the EGFR gene.
C. Gain-of-function mutations in Raf.
D. Gain-of-function mutations in p53.
E. Overexpression of MEK.

Answer 76

D. Gain-of-function mutations in p53.

Question 77

Herceptin is a monoclonal antibody that can recognize HER2, a member of the EGFR family receptors. Before treating breast cancer patients with Herceptin, doctors need to verify that:

A. HER2 gene is amplified or the its expression is higher
B. HER2 gene is lost
C. HER2 has loss-of-function mutation
D. The ligand for HER2 is present
E. None of the above

Answer 77

A. HER2 gene is amplified or the its expression is higher

Question 78

The loss of p53 function could potentially lead to the following defects EXCEPT:

A. Inability to induce cell cycle arrest.
B. Inability to repair DNA damages.
C. Inability to induce apoptosis.
D. Inability to induce necrosis

Answer 78

D. Inability to induce necrosis

Question 79

The “two-hit” hypothesis for tumor suppressors refers to:

A. That an oncogenic activation occurs first before the loss of a tumor suppressor.
B. That two suppressor genes must be inactivated for tumor development.
C. That two mutant alleles for a tumor suppressor must be inherited from father and mother.
D. That two alleles for a tumor suppressor must be inactivated in order to show effect.
E. That one mutant allele must be inherited and another allele must be inactivated in somatic cells.

Answer 79

D. That two alleles for a tumor suppressor must be inactivated in order to show effect.

Question 80

Loss-of-function mutations in DNA repair genes often lead to cancer development. This is because:

A. DNA damages cannot be properly repaired and mutations are accumulated with cell divisions.
B. These DNA repair genes are also involved in apoptosis.
C. All DNA repair genes are also tumor suppressors.
D. DNA repair genes are on the same chromosomes with tumor suppressor genes.
E. All of the above.

Answer 80

A. DNA damages cannot be properly repaired and mutations are accumulated with cell divisions.

Question 81

Targeted therapy is an important treatment strategy for cancer patients. Herceptin is an monoclonal antibody that can bind HER2 and is clinically used to treat breast cancer patients. Which of the following patients may benefit MOST from the use of Herceptin?

A. Patients with HER2 overexpression.
B. Patients with HER2 expression negative.
C. Triple negative patients.
D. Patients with HER1 overexpression
E. Triple positive patients

Answer 81

A. Patients with HER2 overexpression.

Question 82

Susan is diagnosed with breast cancer, and she has amplification of the EGFR gene. She could benefit from the following treatments EXCEPT.

A. EGFR inhibitors.
B. Ras inhibitors.
C. ER targeted anti-hormone therapy.
D. Raf inhibitors.
E. MEK inhibitors.

Answer 82

C. ER targeted anti-hormone therapy.

Question 83

Chronic viral infections could potentially lead to cancer development by the following mechanisms:

A. Some viral proteins may induce chronic inflammatory response.
B. Some viral DNA may integrate into human genome and activate proto-oncogenes. 
C. Some viral proteins may suppress the function of tumor suppressors such as p53 and Rb.  
D. Some viral proteins may disrupt normal cell cycle control.
E. All of the above.

Answer 83

E. All of the above.

Question 84

Some virus such as HTLV-1, HPV and EBV can cause cancer development. Which of the following statements about the mechanisms by which these viruses cause cancer development is FALSE?

A. HTLV-1 TAX  protein can induce chronic inflammatory response.
B. HTLV-1 TAX and HPV E6 can inactivate p53. 
C. HPV E7 can dissociate Rb from E2F.  
D. LMP proteins from EBV can activate mitogenic pathways.
E. Viral proteins are tumor suppressors.

Answer 84

E. Viral proteins are tumor suppressors.

Question 85

Cancer cells have limitless replication potential. This is usually due to:

A. Oncogenic activation of the Ras proto-oncogene.
B. Deletion of  the Rb alleles. 
C. Overexpression of telomerase. 	
D. Amplification of c-Myc oncogene.
E. All of the above.

Answer 85

C. Overexpression of telomerase.

Question 86

B cell infections are kept silent by functional ______
A. M cells
B E6 and E7
C. T cells

Answer 86

T cells

Question 87

Expresses LMP1 and LMP2 that activate mitogenic signaling pathways (B cells)
A. MCPV
B. HTLV-1
C. EBV
D. KSHV

Answer 87

C. EBV

Question 88

Express viral proteins including vFLIP that increases metastasis and angiogenesis
A. MCPV
B. HTLV-1
C. EBV
D. KSHV

Answer 88

D. KSHV

Question 89

Causes Merkel cell carcinoma of skin; requires both infection and then mutations of the Large T antigen to form a truncated version
A. MCPV
B. HTLV-1
C. EBV
D. KSHV

Answer 89

A. MCPV

Question 90

Causes cervical cancer with two viral proteins:
E6 targets ______, E7 targets _____

Answer 90

HPV:
E6 targets p53, E7 targets Rb

Question 91

Produces TAX protein in host cell, increasing the expression of genes that promote proliferation, DNA repair, and resistance to apoptosis
A. MCPV
B. HTLV-1
C. EBV
D. KSHV

Answer 91

B. HTLV-1

Question 92

What is the pathway for colon carcinogenesis?

Answer 92

Loss of APC, GOF mutation of RAS gene, LOF mutation of DCC, SMAD2 and SMAD4 tumor suppressors, Loss of p53

Question 93

Used to estimate gene copy number or IHC to assess protein expression and tissue distribution

Answer 93

FISH

Question 94

Chronic viral infections could potentially lead to cancer development by which of the following mechanisms?
A. Some viral proteins may induce chronic inflammatory response
B. Some viral DNA may integrate into human genome and activate proto-oncogenes
C. Some viral proteins may suppress the function of tumor suppressors such as p53 and Rb
D. Some viral proteins may disrupt normal cell cycle control
E. All of the above

Answer 94

E. All of the above