Practice Questions

TLS Online TPP Program

#Question id: 12482

The Rb protein has been called the “master brake” of the cell cycle. How the Rb protein acts as a cell cycle brake?

#Unit 2. Cellular Organization

Rb bound to E2F and function as transcriptional repressors because Rb recruits chromatin-modifying enzymes that promote deacetylation and methylation of specific histone lysines, causing chromatin to assume a condensed, transcriptionally inactive form.
S phase CDKs and mitotic CDKs maintain Rb protein in the phosphorylated state throughout the S, G2, and early M phases.
Rb bound to E2F and promotes ubiquitinylation of E2F and inhibits chromosomal segregation.
Rb bound to E2F and promotes acetylation which prevents unloading of cohesins.

More Questions

TLS Online TPP Program

#Question id: 2611

#Unit 2. Cellular Organization

Indicator of cell growth,

TLS Online TPP Program

#Question id: 26467

#Unit 3. Fundamental Processes

Which of the following protein reduces the lifetimes of the rrn open promoters to a level at which they are responsive to changes in iNTP and ppGpp concentrations

TLS Online TPP Program

#Question id: 1400

#Unit 4. Cell Communication and Cell Signaling

Which property is shared by malignant tumor cells and transformed cells in culture?

a. reduced growth factor requirement b. attachment-dependent growth

c. loss of actin microfilaments d. altered morphology

TLS Online TPP Program

#Question id: 15003

#Unit 8. Inheritance Biology

Laurie met her husband Jim at a support group for families dealing with PKU (phenylketonurea), a recessive genetic disorder. Laurie and Jim both have one sister who is affected with PKU and no other family history of the disorder. They come to you as a genetic counselor to ask what their risk is of having an affected child. What do you tell them?

TLS Online TPP Program

#Question id: 11115