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Cytogenetics Mcqs

Q:

The target for Obimerson sodium is _________

A) P53 B) Bad
C) Bcl-2 D) IAP
 
Answer & Explanation Answer: C) Bcl-2

Explanation: Obimerson sodium when given with normal chemotherapeutic drugs is a Bcl-2 antisense oblimer. It prevents the expression of Bcl2 anti-apoptotic proteins in proliferative cells leading to apoptosis.

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41
Q:

Decoy molecules which binds to Fas L are seen in _______________

A) Lung cancer B) Melanoma
C) Breast cancer D) Ovarian cancer
 
Answer & Explanation Answer: A) Lung cancer

Explanation: In lung cancer and in colon cancer we see ‘decoy’ molecule that binds to the Fas ligand. Thus, the ligand can no longer induce apoptosis by interacting with the Fas receptor.

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40
Q:

P53 accumilation activates which polymerase to repair DNA damage?

A) Pol alpha B) Pol Beta
C) Pol kappa D) Pol eta
 
Answer & Explanation Answer: C) Pol kappa

Explanation: On sensing the DNA damage p53 level rises which stimulate GADD45 and pol k which tries to repair the DNA damage. Only when the damage is too much to repair apoptosis is triggered.

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37
Q:

Downregulation of caspase 3 can lead to ovarian cancer.

A) True B) False
 
Answer & Explanation Answer: A) True

Explanation: It has been reported that caspase-3 mRNA levels are appreciably downregulated in breast, ovarian, and cervical tumours. Low levels of caspases or impairment in caspase function may lead to decreased apoptosis.

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39
Q:

Which of the following is true for cells with DNA damage?

A) P53 binds to Mdm 2 B) Mdm2 is prosphorylated
C) p53 acts as transcription factor for Bad D) p53 is ubiquinylated
 
Answer & Explanation Answer: B) Mdm2 is prosphorylated

Explanation: In cells with DNA damage chk1 and chk2 kineses phosphorylated Mdm2. Phosphorylated Mdm2 can no longer bind p53 whose level now rises.

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35
Q:

Downregulation of caspase 9 is seen in ________________

A) Melanoma B) Breast cancer
C) Colorectal cancer D) Lung cancer
 
Answer & Explanation Answer: C) Colorectal cancer

Explanation: Reduced functioning of caspases may prevent apoptosis thus leading to cancer. Down regulation of caspase 12 is seen mostly in case of colorectal cancers.

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35
Q:

Which caspase is activated in the ER pathway of apoptosis?

A) Caspase 3 B) Caspase 7
C) Caspase 8 D) Caspase 12
 
Answer & Explanation Answer: D) Caspase 12

Explanation: In extreme hypoxic conditions, the TRAF2 in the ER releases the associated procaspase 12; activated caspase 12 and leads to apoptosis.

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31
Q:

An E6 factor which binds to p53 and thus causes cancer is seem in case of _____________

A) Epstein Barr Virus B) Human Papilloma Virus
C) Melanoma D) Leukemia
 
Answer & Explanation Answer: B) Human Papilloma Virus

Explanation: HPV or Human Papilloma cells produce the E6 factor which binds p53. This in turn prevents the activation of apoptotic pathway triggered by DNA damage and leads to cell proliferation and cancer.

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