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cell cycle questions

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Cancer 3

Question 1 of 28

1

All of the following are the subphases of interphase except?

Select one of the following:

  • G1 phase

  • S Phase

  • G2 phase

  • M phase

Explanation

Question 2 of 28

1

A restriction point is when

Select one of the following:

  • a cell is irreversibly committed to cell cycle progression or apoptosis

  • a cell is reversibly committed to cell cycle progression or apoptosis

  • None of the above

Explanation

Question 3 of 28

1

Cell cycle is regulated by Cyclin-dependent kinases true or false

Select one of the following:

  • True
  • False

Explanation

Question 4 of 28

1

All of the following about Cdks are true except

Select one of the following:

  • Cdk levels are usually constant

  • Cdks are inactive in the absence of Cyclin

  • Cdks are activated by binding to Cyclins

  • Cdks phosphorylate cell regulatory proteins

  • Cdk levels vary with cell cycle

Explanation

Question 5 of 28

1

All of the following are true about Cyclin D except?

Select one of the following:

  • It is made at the start of G1 by growth factor mediated gene transcription

  • Cyclin D binds and activates CDK4,6

  • Cyclin D is degraded at the end of G1

  • Cdk 4/6 is active in the absence of cyclin D

Explanation

Question 6 of 28

1

all of the following are true except?

Select one of the following:

  • Cyclin D-CDK 4/6 will phosphorylate Rb

  • Activated Rb will release E2F

  • E2F will cause Cyclin E synthesis

  • Cyclin E binds and activates CDK-2

  • Dephosphylated Rb is active

Explanation

Question 7 of 28

1

DNA damage-induced pathways target degradation of Cyclin D first and then Cyclin E which stops cell cycle progression true or false

Select one of the following:

  • True
  • False

Explanation

Question 8 of 28

1

hypophosphorylated Rb prevents E2F activity thereby preventing cell cycle progression true or false

Select one of the following:

  • True
  • False

Explanation

Question 9 of 28

1

All of the following about negative regulators of cell cycle are correct except?

Select one of the following:

  • INK4 (inhibitors of kinase4) family bind and inhibit only cyclin D-Cdk4/6 complexes at restriction point p15,p16

  • CIP (Cdk inhibitory protein) family bind and inhibit all cyclin-Cdk complexes at the restriction point p21

  • p16 normally inhibits Cdk4

  • in the absence of p16 Cdk 4 is active and phosphorylate Rb wichin in turn activates E2F

  • p16 normally activates Cdk4

Explanation

Question 10 of 28

1

Normally p53 levels are kept low by MDM2 true or false

Select one of the following:

  • True
  • False

Explanation

Question 11 of 28

1

All of the following about p53 are correct except?

Select one of the following:

  • p53 expressed at very high levels normally

  • DNA damage leads to phosphorylation of p53 stabilizing it and increasing its concentration

  • p53 acts as transcriptional activator increasing synthesis of Cdk inhibitor p21

  • p21 inhibits Cdk/ cyclin G1 and S complexes --> cell cycle arrest in G1

Explanation

Question 12 of 28

1

Abnormally high level of Myc causes systhesis of ARF which binds and inhibits MDm2 causing increase p53 which causes cell cycle arrest true or false

Select one of the following:

  • True
  • False

Explanation

Question 13 of 28

1

Cell cycle progression at check point 2 (G2-M) is regulated by phosphorylation of Cdk1-Cyclin B complex true or false

Select one of the following:

  • True
  • False

Explanation

Question 14 of 28

1

All of the following are inducers of apoptosis except?

Select one of the following:

  • Virus infected cells

  • DNA damage

  • Growth factor withdrawal

  • Ionising radiation

  • Calcium eflux

  • tumor necrosis factor

Explanation

Question 15 of 28

1

Following is the sequence of Extrinsic apoptotic pathway except?

Select one of the following:

  • Extrinsic apoptotic pathway is initiated by binding of death-inducing ligand to a death receptor (Cys-rich repeat in the extracellular domain)

  • Death receptor are FasR and TNF receptor which are integral membrane proteins with their receptor domains exposed at the surface of te cell

  • binding of the death activator (FasL and TNF-alpha) leads to activation of caspase -9

  • which in turn initiates a cascade of caspase activation leading to cell death

Explanation

Question 16 of 28

1

All of the following are pro-apoptotic genes except

Select one of the following:

  • Bcl-2

  • Bax

  • Diva

  • Bad

  • Bik, Bim

Explanation

Question 17 of 28

1

Bid links he 2 apoptotic pathways (extrinsic and intrinsic) true or false

Select one of the following:

  • True
  • False

Explanation

Question 18 of 28

1

Both pathways converge on the activation of Caspase-3,6,7 true or false

Select one of the following:

  • True
  • False

Explanation

Question 19 of 28

1

All of the following stimulate angiogenesis except

Select one of the following:

  • VEGF

  • FGF

  • EGF

  • Angiotropin

  • Angiogenin

  • Angiostatin

  • TIP Statin anywhere stops (from static)

Explanation

Question 20 of 28

1

Hypoxia --> HIF which induces VEGF which binds to RTK and dramatically decreases metastatic potential - true or false

Select one of the following:

  • True
  • False

Explanation

Question 21 of 28

1

VEGF is secreted by all of the following except?

Select one of the following:

  • Healthy tissues needing more blood

  • Hypoxic tissues

  • Tumors

  • Highly oxygenated tissues

Explanation

Question 22 of 28

1

All the following statements are true except?

Select one of the following:

  • Bevacizumab blocks VEGF

  • Sunitinib, Sorafenib block VEGFR

  • Angiostatin inhibits plasminogen fragment

  • Endostatin inhibits endothelial cell BM collagen XVIII fragment

  • Tumstatin inhibits collagen IV fragment

  • Thrombospondin inhibits Fas-R expression

  • Cefuximab inhibits EGFR

  • Herceptin (Trastuzumab) inhibits HER2

Explanation

Question 23 of 28

1

All of the following are true except?

Select one of the following:

  • Serine proteases (uPA, tPA, plasminogen) activate MMPs

  • MMPs digest ECM by digesting type IV collagenase

  • Plasminogen promotes clotthing

Explanation

Question 24 of 28

1

Tumor motility factors AMF,HGF, EGF all promote motility via Rho GTPases - true or false

Select one of the following:

  • True
  • False

Explanation

Question 25 of 28

1

Tumor arrest in a specific tissue is by chance only true or false

Select one of the following:

  • True
  • False

Explanation

Question 26 of 28

1

Breast cancer cell express CXCR4, which bind to ligand CXCL12 in the lung,liver and bone - true or false

Select one of the following:

  • True
  • False

Explanation

Question 27 of 28

1

Major limiting step of the metastasis is the hospitability of the host microenvironment true or false

Select one of the following:

  • True
  • False

Explanation

Question 28 of 28

1

The following are matched properly except

Select one of the following:

  • Topisomerase II inhibitors: Doxorubicin and Daunorubicin

  • Vinca alkaloids (Vinblastine and Vincristine) enhances polymerization of microtubles

  • Taxol(Paclitaxel) binds and stabilizes microtubles

  • Borezomib (Velcade) blocks proteasome activity which prevents IkB degradation build up of Bax and Bak which leads to apoptosis

  • Tarceva and Iressa inhibit EGFR TKi

  • Imatinib?Gleevec inhibit TKi in CML

Explanation

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