In: Biology
42.
What role do growth factors have in cancer?
Select one:
They bind to E2F, skipping the G1 checkpoint
They result in too many cyclins, affecting Rb and E2F
They bind to Cdk, skipping the G1 checkpoint
They make cells grow faster
They bind to Cdk, resulting in the S phase proceeding
43.
With respect what can cause cells to become cancerous, what is the significance of adding a phosphate (P) to the molecule Rb?
Select one:
it causes the release of growth factors
it deactivates E2F, stopping the cell cycle
it releases E2F resulting in cells producing more growth factors
it releases E2F resulting in cells replicating chromosomes and eventually dividing
it causes the binding of cyclins to Cdk
44.
Individuals that are carriers of the Cystic Fibrosis allele ____________:
Select one:
must always have children with the disease
have no chance of having children with the disease
have a heterozygous genotype
have the disease
have a homozygous genotype
46.
A cyclin-dependent kinase (Cdk) is ________.
Select one:
a growth factor in cells
a molecule that binds to cyclins in the cell cycle checkpoints
used to substitute for E2F in cancer cells
part of the chiasmata in meiosis
used in mitosis to move the chromosomes
##### Answer and Explanation #####
What role do growth factors have in cancer?
Answer- They make cells grow faster
Explanation- Since the growth factors help in the regulation of progression in the various phases of the cell cycle in the regulated manner but in case of Cancerous cell, The growth factors loss their regulation properties resulting the cancer. Here we can understand it with the help of Rb (Retinoblastoma) that is a growth factor and regulates the cell cycle progression from G1 to S-phase.
In this progression Rb binds with E2F in the normal condition and controls the progression by phoshorylating Rb to free E2F which further transcripts the factors that allow the cell to progress if all the cell settings are right. But in case of loss of function in Rb (mostly in hyper phoshorylation), the cell cycle deregulates and becomes cancerous cell.
Loss of function can lead to increase in metastatic potential, that ultimately leads to the fast growing of the cells.
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