Question 1

1. This regulator removes the inhibitory phosphate on the Tyr–15 residue of most Cdks a. Cyclin-dependent activating kinase b. Cdc25 phosphatase c. Cdk inhibitor d. Ubiquitin ligase e. Wee1 kinase

Accepted Answer

B

Question 2

``` 2. The so-called mitosis/maturation-promoting factor (MPF) that becomes active during the M phase consists of a. Cyclin B/Cdk 1 b. Cyclin D/Cdk 4,6 c. Cyclin A/Cdk 1,2 d. Cyclin E/Cdk 2 ```

Accepted Answer

A

Question 3

3. Which control structure on Cdks rotates away from the catalytic area during Cdk-cyclin complex formation, and at the same time aligns key amino acid residues for better reception of the substrate ATP? a. T-loop (hello Tachy. From a bored transcriber. Hahahaa. PS DELETE THIS) b. preRC c. PSTAIR helix d. Cyclin

Accepted Answer

C

Question 4

``` 4. Cdks and cyclins are generally synthesized via this pathway with the help of growth factors and mitogens a. NF-κB pathway b. SMAD pathway c. ERK/MAPK pathway d. JAK-STAT pathway ```

Accepted Answer

C

Question 5

5. The prereplicative complex (preRC) is formed during this/these phase/s of the cell cycle, when there are no detectable levels of Cdks and cyclins a. G1 to S b. S phase c. M phase d. M to early G1

Accepted Answer

D

Question 6

6. The following statements regarding the G1/S checkpoint are true, EXCEPT a. The trigger protein ATR is activated when damage to DNA is detected b. A serine/threonine kinase, Chk2, is phosphorylated by the trigger protein c. Phosphorylation and activation of another important protein, p53, also occurs d. Extensive crosstalk exists between the G1/S and G2/M checkpoint pathways

Accepted Answer

A

Question 7

7. Which of the following does not occur during apoptosis? a. Activation of caspases and endonucleases b. Chromatin condensation or pyknosis c. Formation of cytoplasmic blebs and apoptotic bodies d. Induction of an inflammatory response

Accepted Answer

D

Question 8

8. The DISC (death-inducing signaling complex) consists of the following, EXCEPT a. Cytosolic adaptor proteins containing death and death-effector domains b. Ligands (FasL and TNFα) to death receptors c. Membrane-associated death receptors containing death domains ￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼ d. Effector caspases, which also contain death-effector domains

Accepted Answer

B

Question 9

9. Caspase-activating complexes involved in the intrinsic pathway of apoptosis are a. Apoptosomes b. PIDDsomes c. Death-inducing signaling complexes d. A and B only e. B and C only

Accepted Answer

D

Question 10

0. The following statements regarding the BCL-2 family of proteins and the intrinsic apoptotic pathway are true, EXCEPT a. BH3-only proteins appear to be pivotal in activating the intrinsic apoptotic pathway b. Anti-apoptotic proteins are believed to be neutralized by BH3-only proteins during apoptosis c. A BH3-only protein, PUMA, can directly target pRb to cause it to trigger apoptosis d. In the intrinsic pathway, pro-apoptotic proteins allow cytochrome c to exit mitochondria

Accepted Answer

C

Question 11

11. The two apoptotic pathways eventually integrate or merge together at the level of a. Executioner caspases b. Cytochrome c c. Initiator caspases d. BH3-only proteins

Accepted Answer

A

Question 12

12. This pathway, which works to promote cell proliferation, is activated when glucose supply is abundant. It is also responsible for internalizing and storing this ambient glucose in proliferating cells via insertion of GLUT transporters into the cell membrane and activation of glycogen synthase. a. ERK/MAPK pathway b. JAK-STAP pathway c. SMAD pathway d. PI3K/Akt pathway

Accepted Answer

D

Question 13

13. According to Knudson’s two-hit hypothesis, the so-called “first hit” of an individual with sporadic retinoblastoma is which of the following? a. A somatic mutation occurring in one of the alleles of the RB1 gene, where both of the alleles are normal to begin with b. A somatic mutation occurring in the remaining normal RB1 gene allele; the other allele suffered a somatic mutation some time back c. A germline mutation present in one of the RB1 alleles that the individual inherited from his parents d. A somatic mutation occurring in the remaining normal RB1 gene allele; the other allele already carries a germline mutation inherited from one of the parents

Accepted Answer

A

Question 14

14. Tumor a. Autosomal dominant suppressor genes have this mode of activation mutation b. X-linked recessive c. Mitochondrial inheritance d. Autosomal recessive

Accepted Answer

D

Question 15

15. If the normal activity of p53 protein (the “guardian of the genome”) is lost, which of the following is lost? a. Expression of Cdk inhibitors p16 and p21 b. Maintenance of pRb in the dephosphorylated state c. Keeping the transcription factor E2F in the bound and inactive state d. All of the above e. Only B and C

Accepted Answer

D

Question 16

16. Which type of cancer has the highest prevalence of somatic mutations to the gene encoding p53? a. Lung b. Colorectal c. Breast d. Pancreatic

Accepted Answer

B

Question 17

17. The following statements regarding oncogenes are true, EXCEPT a. These encode proteins that promote cell division/survival, or resistance to apoptosis b. Mode of activating mutation is of the autosomal dominant type c. The Ras oncogene, for instance, is present in roughly 25-30% of human cancers d. Generally, the mutations can either be heritable (germline) or acquired (sporadic)

Accepted Answer

D

Question 18

18. The oncogene BCR-ABL1, contained in the Philadelphia chromosome [t(9;22)], encodes for this kind of protein product a. Receptor tyrosine kinase b. Transcription factor c. Regulatory GTPase d. Cytoplasmic tyrosine kinase

Accepted Answer

D

Question 19

19. Which of the following scenarios best describes targeted therapy in cancer treatment? a. Azathioprine is an antimetabolite that ‘impersonates’ a purine, which leads to disruption of normal cell development and division b. Gleevec/Glivec, used for CML, inhibits the kinase activity of the Bcr-abl fusion protein responsible for uncontrolled myelocyte proliferation c. Tamoxifen (specifically its metabolite) competitively binds to estrogen receptors on breast cancer cells, arresting them in the G0 and G1 phases d. Doxorubicin, used in Hodgkin’s lymphoma, intercalates in tumor cell DNA, thereby preventing topoisomerase II from relaxing any supercoils that develop

Accepted Answer

B

Question 20

20. The following statements regarding carcinogenesis are correct, EXCEPT a. Mutation/damage/conversion of tumor suppressor genes and proto-oncogenes occurs during tumor initiation b. The minimum requirements for this process includes pRb and p53 suppression, Ras activation, and telomerase overexpression c. Cancer development involves purely genetic events, and a maximum of only 2 “genetic hits” are required in the process i. Cancer is a result of accumulated mutations (hits) to a cell’s DNA d. Mutations may give a cell a selective advantage in terms of growth and survival, and may become a founder of a growing mutant clone

Accepted Answer

C

Question 21

``` 21. NMDA, AMPA, and Kainate receptors are ion channels that make use of this neurotransmitter as activating ligand ￼￼￼￼￼￼￼ a. GABA b. Glycine c. Glutamate d. ATP ```

Accepted Answer

C

2nd Sem - 8th Evals Batch 2018 Flashcards