Question

1. As illustrated the M phase of the cell cycle has a unique "off" mechanism.
Two enzyme complexes, the APC/C and SCF ubiquitin ligases are essential for progress to cytokinesis.
The function of these ligases is to:
a. Synthesize G1/S cyclins
b. Catalyze the ubiquitylation and consequent destruction of specific regulatory proteins that control critical events in the cycle
c. Arrest the cycle when the cell either fails to complete an essential cell-cycle process
d. Control the activities of cyclin-Cdk complexes include phosphorylation of the Cdk subunit, binding of Cdk inhibitor proteins (CKIs)
e. Activation of M-phase cyclin-Cdk complexes (M-Cdk)

2. The biochemical markers of programmed cell death include:
a. Cytotoxicity
b. DNA digestion by endonucleases
c. Formation of mitotic spindles
d. Massive exocytosis
e. Uptake of water by osmosis

3. In some lung cancers the X-linked inhibitor of apoptosis protein (XIAP) binds to the processed form of caspase-9, and suppress the activity of apoptotic activator cytochrome c.
The fate of these cells is to:
a. Undergo necrotic cell death
b. Undergo programmed cell death
c. Form a tumor
d. Enter M phase
e. Form germ cells

4. Which is NOT a signaling event coupled to cell growth?
a. Myc activation
b. P53 activation
c. TRK activation and cross phosphorylation
d. PI 3 kinase activation
e. Tor mediated uptake of cellular nutrients

5. Which defect can lead to carcinogenesis?
a. Chromosome instability
b. DNA methylation
c. Heterochromatin formation
d. Point mutations in protein coding regions
e. Deletion mutations in noncoding regulatory regions of genes

6. Which is NOT true of the mitotic spindle (tubulin filaments and centrosomes)?
a. It forms from components of the interphase microtubular spindle (tubulin filaments and centrosomes)
b. It orients the axis of cytokinesis
c. Mutable microtubules attach to each chromosome pair at the kinetochore
d. Myosin motor proteins pull the chromatids apart
e. The spindle pole is made from centrosomes

8. This image represents 2 stages of cancer (neoplastic) progression. The safe(r) kind of neoplastic lesion is:
a. Malignant
b. Benign
c. Metastatic
d. Invasive carcinoma
e. Genetically unstable

9. Which modern screening methods help aid in identification of new cancer-critical genes and carcinogens?
a. Comparative Genome Hybridization
b. DNA microrrays
c. RNAi screens
d. Mouse expression models
e. Ames test
f. All of the above
g. None of the above

10. Which event is not activated by M-CDK?
a. Triggers the events of early mitosis
b. Chromosome condensation
c. Bipolar attachment of the sister chromatid pairs to microtubules of the spindle
d. Assembly of the nuclear envelope
e. Stimulate chromosomes to assist in microtubules nucleation and stability

11. The figure illustrates the first steps in regulating progression of cell cycle phases.
Cdk proteins (cyclin dependent protein kinases) are expressed at all times.
The key for the cell cycle control system to regulate cell cycle progression is:
a. Controlling the accumulation of cell cycle phase-dependent cyclin proteins
b. Dephosphorylating cyclin-dependent kinases
c. Releasing calcium from the sarcoplasmic reticulum
d. Action potentials in myelinated neurons
e. Secretion of mitogens

12. Mutations in which genes are found in almost all human tumors?
a. Ras
b. Myc
c. p53
d. Rb
e. Tor
f. a) and c)
g. All of the above

13. The lining epithelium for stomach is:
a. Simple squamous epithelium
b. Simple cuboidal epithelium
c. Simple columnar epithelium
d. Transitional epithelium
e. Stratified squamous epithelium

14. The lining epithelium for Proximal convoluted tubule is:
a. Simple squamous epithelium
b. Simple cuboidal epithelium
c. Simple columnar epithelium
d. Transitional epithelium
e. Stratified squamous epithelium

15. Gastrin and somatostatin are secreted by:
a. Chief cells
b. Parietal cells
c. APUD cells
d. Mucosal cells

16. In anaphase the paired chromosomes split and migrate to cell poles.
Which is NOT a property of anaphase?
a. Anaphase is triggered by the APC/C
b. APC/C also promotes cyclin destruction and thus the inactivation of M-Cdk cyclin destruction and thus the inactivation of M-Cdk.
c. The resulting phosphorylation of CDK targets is required for the events that complete mitosis
d. expression of the securin protein that will clasp the two condensed sister chromatids together.

17. Which of the following is true?
a. Tumor initiators introduce mutations into somatic cells
b. Benign cancers invade surrounding tissues and colonize distant organs
c. Cancer cells induce apoptosis in response to cell stress or DNA damage
d. Metastatic cancers activate the intrinsic, but not extrinsic, apoptosis pathway
e. Cancer cells acquire stable genetic phenotypes

18. Which of the following is false?
a. Cancer progression relies on accumulating many mutations in cancer critical genes
b. Tumor initiators are environmental effectors that change gene expression patterns
c. Tumor promotors do not alter genetic makeup
d. Epigenic events that promote tumor growth are not passed along to offspring
e. Frequently involves turning off proapoptotic signaling pathways

19. Duplication of the chromosomes in S phase does NOT involve:
a. accurate copying of the entire DNA molecule in each chromosome
b. duplication of the chromatic proteins that associate with the DNA
c. activation of S-Cdk, which activates proteins that unwind the DNA and initiate its replication at sites
d. S-Cdk activates proteins bind to the DNA sequence at the Ori (Origin of replication) and initiate multiple rounds of DNA replication

20. Which is NOT true of programmed cell death?
a. The extrinsic pathway is initiated by external signaling proteins
b. The intrinsic pathway initiation is mitochondrially regulated
c. The extrinsic pathway will recruit the intrinsic pathway
d. The process is reversible when started
e. Macromolecular complexes assemble and recruit procaspases for activation

21. The part of GIT which has more than one layer of epithelial cells lining it is:
a. Esophagus
b. Stomach
c. Duodenum
d. Jejunum
e. Colon

22. While examining the tissue sample taken from trachea & large bronchii from a chronically smoking patient suffering with Small cell carcinoma of lungs, the pathologist noted that the epithelium is stratified and columnar in nature.
This finding is:
a. Normal histological finding:
b. Abnormal with the abnormality being the presence of columnar cells
c. Abnormal as the normal histology is simple columnar cells
d. Abnormal as the normal histology is pseudo-stratified columnar cells
e. Abnormal as the normal histology is stratified cuboidal cells

23. After mitosis completes the formation of a pair of daughter nuclei, cytokinesis finishes the cell cycle by dividing the cell itself.
Which is NOT true of cytokinesis?
a. It occurs in late M phase
b. It is activated by cyclin c (cytokinesis)-dependent kinases
c. It requires actin and myosin assembly and contraction to form the cleavage furrow
d. positioning of the contractile ring is determined by signals emanating from the microtubules of the anaphase spindle
e. The two daughter cells position themselves to re-enter S phase

24. Which NOT an examples of a mutagen?
a. EGF
b. Cigarette Smoke
c. UV light
d. Chemical carcinogens
e. Asbestos

26. Which proteins are NOT involved in programmed cell death?
a. IAP
b. Apoptosome
c. Cytochrome c
d. PI 3 Kinase
e. Caspase

27. The lining epithelium for thick part of Henle's loop is:
a. Simple squamous epithelium
b. Simple cuboidal epithelium
c. Simple columnar epithelium
d. Transitional epithelium
e. Stratified squamous epithelium

28. A researcher while evaluating various histological samples came across an epithelial tissue whose primary function appeared to be diffusion.
Which of the following epithelial tissues do you think is the researcher looking at?
a. Stratified squamous epithelium
b. Stratified cuboidal epithelium
c. Transitional epithelium
d. Simple squamous epithelium
e. Simple cuboidal epithelium
f. Simple columnar epithelium

29. Tumors are NOT thought to originate from….
a. Somatic cell mutation and epigenetic changes accompanied by natural selection
b. A single cell that has experienced an initial mutation followed by exposure to tumor promoters
c. A tissue stem cell
d. A differentiated cell that acquires the capacity for indefinite self-renewal
e. Mutation of only one of the critical cancer genes

30. The cell death cascade depends on:
a. The cell cycle S phase
b. Binding of external death signals
c. Release of mitochondrial Ca2+ and cytochrome c
d. Mitogenic factors
e. b) and c)
f. None of the above

31. Which is NOT a productive therapy to combat cancerogenesis?
a. Early detection and surgical intervention
b. Inactivation of oncogenes
c. Introduction of angiogenic growth factors
d. Activation of apoptotic pathways
e. Modification of exposure to environmental factors

32. Which is NOT true of cancer-critical genes?
a. Gain of function genes are genetically dominant
b. Proto-oncogenes activate programed cell death
c. Loss-of-function mutation of tumor suppressor genes abolish the inhibitory controls that normally hold cell numbers in check
d. Specific cancer-critical genes are mutated in the majority of all cancers
e. Proto-oncogenes are activated by mutation to cancer promoting oncogenes

33 Aflatoxin B1 (see image) and Benzo[a]pyrene are proven mutagens.
Which is NOT a property of these chemicals?
a. They cause mutations to nucleic acids
b. They are activated into carcinogens by Cytochrome P-450 oxidases in the liver
c. Aflatoxin is a fungal product on fermenting peanuts
d. Benzo[a]pyrene is a component of cigarette smoke
e. They are tumor promoters

34. Properties of metastatic cancer cells do NOT include:
a. Recruiting support from stroma cells
b. Release angiogenesis promoting factors as sites of secondary tumors
c. Display contact dependent inhibition of cell growth and proliferation
d. Propagate DNA defects to daughter cells
e. Acquired the capacity for indefinite self-renewal

35. Which is NOT considered a risk factor for carcinogenesis?
a. Over eating animal meat and fats
b. Over eating
c. Viral or parasitic infections
d. Childbirth over age 35 yrs
e. Chronic inflammation/injury
f. All of the above
g. None of the above

36. If cells accumulate enough genetic damage they will continue to replicate despite being directed to die.
Which protein activities would direct such a cell fate?
a. Over activation of anti-apoptotic Bcl proteins
b. Inactivating mutations of p53
c. Unregulated transcription of interferon genes that induce p53 expression
d. Overactivation of Fas death receptor proteins
e. Deletion of the pro domain on executor caspases
f. a) and b)
g. b) and d)

37. Which cell type would NOT have an active executioner procaspase program?
a. Epithelial cells
b. White blood cells and derivatives
c. Neutrophiles
d. Stem cells

38. Which is NOT true about cell growth?
a. Mitogens stimulate the rate of the cell division by removing intracellular molecular brakes that restrain cell-cycle progression in G1
b. Growth factors promote cell growth by stimulating the synthesis of macromolecules
c. Growth factors promote cell growth by inhabiting the degradation of macromolecules
d. Animals maintain the normal size of their tissues and organs by adjusting cell size to compensate for changes in cell number, or vice versa
e. Mitogens bind to nuclear receptors

39. Mutations in tumor suppressor genes are NOT:
a. Generally recessive
b. Cells tend to behave normally until both gene copies are deleted, inactivated, or silenced epigenetically
c. Loss or inactivation is a common feature of many sporadic cancers
d. Inheritance of one defective and one functional copy leads to increased predisposition toward developing cancer
e. Gain-of-function mutations

40. The regulation of cell growth, cell division, and cell death are all coordinated.
If faulty, which dysregulation would lead to a neoplastic state?
a. Over expression of receptor tyrosine kinases
b. Over expression of p53
c. Inactivation of Ras
d. Over activation of IAP proteins
e. Deletion of a single copy of a tumor suppressor gene

41. Which is NOT true of programmed cell death?
a. The extrinsic pathway is initiated by external signaling proteins
b. The intrinsic pathway initiation is mitochondrially regulated
c. The extrinsic pathway will recruit the intrinsic pathway
d. The process is reversible when started
e. Macromolecular complexes assemble and recruit procaspases for activation

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1. As illustrated the M phase of the cell cycle has a unique "off" mechanism.
Two enzyme complexes, the APC/C and SCF ubiquitin ligases are essential for progress to cytokinesis.
The function of these ligases is to:
d. Control the activities of cyclin-Cdk complexes include phosphorylation of the Cdk subunit, binding of Cdk inhibitor proteins (CKIs)...

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