#Question id: 2975
#Unit 2. Cellular Organization
Following statements are regarding to the Surveillance mechanisms in cell cycle regulation.
A. Surveillance mechanisms known as checkpoint pathways establish dependencies among cell cycle events and ensure that the next cell cycle event does not occur prior to the completion of a preceding event.
B. In response to DNA damage, two related protein kinases, ATM and ATR, are recruited to the site of the damage, where they activate signaling pathways that lead to cell cycle arrest, repair, and under some circumstances, apoptosis.
C. The spindle assembly checkpoint pathway, which causes initiation of anaphase, utilizes Mad2 and other proteins to regulate APC/CCdc20, which targets securing and mitotic cyclins for ubiquitinylation.
D. The spindle position checkpoint pathway prevents mitotic CDK inactivation when the spindle is mispositioned. In this pathway, localized activators and inhibitors and a sensor that shuttles between them allow cells to sense spindle position.
Which of the following statement is incorrect?
#Question id: 2976
#Unit 2. Cellular Organization
Match the following Regulators with its functions.
|
Column I |
Column II |
|
A. Wee1 kinase |
i. Degradation of phosphorylated Sic1 or p27KIP1 |
|
B. Cdc25A phosphatase |
ii. Induces degradation of B-type cyclins |
|
C. APC/CCdc20 |
iii. Activates vertebrate S phase CDKs |
|
D. SCF |
iv. Inhibits CDKs |
Which of the following is correct?
#Question id: 2977
#Unit 2. Cellular Organization
The mitotic exit network that localizes to spindle pole bodies and whose activity is regulated by spindle position belongs to the family of signaling pathways known as the Hippo pathway in metazoans. Following statements are-
A. The conserved core of the Hippo signaling pathways consists of the Hippo protein kinase, which activates the Lats-Mob1 kinase.
B. The kinases are organized by a scaffolding molecule that, at least in budding and fission yeasts, targets the kinase cascade to centrosomes.
C. As in many kinase signaling cascades, a GTPase controls the activity of the mitotic exit network and the septation initiation network.
D. In metazoans, activation of the Hippo pathway leads to tissue overgrowth because the transcriptional activator TAZ (known as YAP in the mouse) constitutively promotes the expression of growth- and proliferation-promoting genes.
Which of the following statements are incorrect?
#Question id: 2978
#Unit 2. Cellular Organization
The most important regulatory control that restricts cyclins to the appropriate cell cycle stage is ubiquitin mediated, proteasome-dependent protein degradation. Which of the following statement is incorrect regarding to the degradation of protein?
#Question id: 2979
#Unit 2. Cellular Organization
Use the data in the accompanying table to answer the question. Minutes Spent in Cell Cycle Phases-
|
Cell type |
G1 |
S |
G2 |
M |
|
Beta |
18 |
24 |
12 |
16 |
|
Delta |
100 |
1 |
0 |
0 |
|
Gamma |
18 |
48 |
14 |
20 |
#Question id: 2980
#Unit 2. Cellular Organization
Following statements are regarding to the protein phosphatase Cdc14 function in budding yeast.
A. In budding yeast, the protein phosphatase Cdc14 throws the switch between two mutually antagonistic states during anaphase.
B. Cdc14 is kept inactive during most of the cell cycle, but is activated during anaphase by a GTPase signaling pathway known as the mitotic exit network.
C. Mitotic exit network is unresponsive to spindle position and becomes active in anaphase.
D. Cdc14 phosphatase activated by the activation of protein kinase cascade.
E. Cdc14 dephosphorylates APC/CCdh1 and Sic1 to promote mitotic cyclin degradation
and mitotic CDK inactivation, respectively. This process leads to exit from mitosis.
Which of the following combination is incorrect?