TLS Online TPP Program

#Question id: 2471


Small G proteins, including Rho, Rac, and Cdc42, contribute to the coordinated movement and overall polarity of a migrating cell.  Assuming that the cell is migrating in a left-to-right fashion, which of the following is correct?

#Unit 2. Cellular Organization
  1. active Cdc42 at the leading edge of the cell and active Rho at the back of the cell

  2. active Rac at the back of the cell and active Cdc42 at the front of the cell

  3. active Cdc42 at the back of the cell and active Rac at the leading edge of the cell

  4. active Rac at the leading edge of the cell and active Rho at the back of the cell

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TLS Online TPP Program

#Question id: 4073

#Unit 3. Fundamental Processes

The expression of which gene(s) is (are) regulated by promoter proximal pausing?

TLS Online TPP Program

#Question id: 4074

#Unit 3. Fundamental Processes

The promoter sequences of RNA polymerase III-transcribed genes are located

TLS Online TPP Program

#Question id: 4075

#Unit 3. Fundamental Processes

Pre-mRNA molecules

a. exist as free RNA molecules in eukaryotic cells.

b. are associated with an abundant set of nuclear proteins.

c. are mostly located in the cytoplasm.

d. are located in the nucleus.

TLS Online TPP Program

#Question id: 4076

#Unit 3. Fundamental Processes

RNA-binding proteins

a. can be identified by chromatography of UV irradiated nuclear extracts over oligo-dT columns.

b. can be identified by sequence homology to known RNA-binding domains.

c. have a conserved structure as seen by X-ray crystallographic analysis.

d. alter the secondary structure of pre-mRNAs, which decreases interactions with other RNAs or proteins.

e. always remain in the nucleus.

TLS Online TPP Program

#Question id: 4077

#Unit 3. Fundamental Processes

Which of the following is (are) associated with most polyadenylation events?

a. cleavage of the 5´ end of the RNA molecule

b. an assembly of a large, multiprotein complex

c. the AAUAAA site upstream of where polyadenylation will occur

d. a GU-rich or U-rich region near the cleavage site

e. slow addition of A residues followed by rapid addition of 200 to 250 more A residues

TLS Online TPP Program

#Question id: 4078

#Unit 3. Fundamental Processes

Which of the following is (are) required for splicing to occur?

a. two transesterification reactions

b. intact, naturally occurring introns

c. formation of a lariat like structure

d. a branch-point G residue