Cell Bio - Test 4
Mitotic cyclin levels at the ends of mitosis are regulated by which of the following
Degradation of M cyclin by APC/C-Cdh1
T/F People who inherit one copy of the RB gene that is normal and one copy that is mutated- have a greatly increased risk of cancer.
False
T/F Protein kinase B phosphorylate Bad and other anti-apoptotic proteins making them active
False
T/F The release of calcium from the ER is essential for the PKR to produce the second messengers, DAG and IP3 from membrane bound PIP2
False
T/F: APC/C- Cdc20 proteasome degrades securing which holds the sister chromatids together, leading to the metaphase to anaphase transistion
False
The SOS protein has which of the following functions
guanine nucleotide exchange protein
Increased CED-9
no effect on apoptosis
The first demonstration that cancer could be caused by a virus involved
rous sarcoma virus in chickens
Each of the following occurs during apoptosis of a cell except
rupture of a cell, releasing cytoplasmic contents for phagocytosis
During which stages is APC/C-Cdh1 active
second half of mitosis and G1
Myc
Oncogene
Src
Oncogene
The growth factor MightyChick stimulates the proliferation of cultured chicken cells. The receptor that binds MightyChick is a receptor tyrosine kinase (RTK), and many chicken tumor cell lines have mutations in the gene that encodes this receptor. Which of the following types of mutation would be expected to promote uncontrolled cell proliferation?
A mutation that inactivates the phosphatase that normally removes phosphates from tyrosines on the activated receptor
Each of the following statements regarding CD95-stimulated programmed cell death is true except
Adaptor proteins stimulate the P13K-Akt pathway
Tumor cells in the iris of teh eye are actively producing both VEGF and FGF, factors that stimulate angiogenesis, but no new network of blood vessels to the tumor has been established in spite of the fact that blood vessels are nearby. This observation suggests that most likely
Angiostatin, an angiogenesis inhibitor is present in greater concentration
Inactivating mutation of Bim
Apoptosis less likely
Each of the following would inhibit cell progression through the cell cycle except
CAK kinase phosphorylation of the mitotic Cdk/cyclin complex
Cells lacking the ability to produce a functional Caspase 9 protein are cultured in the presence of a growth factor. Expression of a constitutively active version of which of the following proteins could induce apoptosis in these cells?
Caspase 3
The mitotic exit network requires which of the following activations
Cdc14
Mitogens are added to the medium of cultured human cells that are synchronized in mitosis. The mitogen is washed way after these cells have passed START in the cell cycle. These cells will progress through the cell cycle then arrest in which phase?
G0/G1
Raf is to MEK, as MEK is to
MAPK
Individuals can inherit a defective APC gene on chrome 5 from one parent that makes them susceptible to developing familial adenomatous polyposis. In which cells is this deletion present in affected individuals
all cells
Delete CED-3
apoptosis less likely
Deletion of CARD domain from Apaf-1
apoptosis less likely
BCL-2 protein deleted
apoptosis more likely
FAS death receptors can cluster without the need for the FAS ligand
apoptosis more likely
Procaspase 9 can self-proteolytically cleave
apoptosis more likely
What would be the most obvious outcome of repeated cell cycles consisting of S phase and M phase only/
cells produced would get smaller and smaller
Epigenetic changes in gene expression that can lead to cancer by silencing tumor suppressor genes are mediated by
changes in normal DNA methylation
BRCA1
tumor suppressor
P53
tumor suppressor
Hereditary cancers typically possess loss-of-heterozygosity in
tumor-suppressor genes
All of the following statements about destruction of cyclins is (are) true except
ubiquitin targets CDKs
M-cyclin is present from S-phase but is inactive in the cyclin-Cdk complex by which of the following?
wee1
