TLS Online TPP Program

#Question id: 4994


In certain motile prokaryotes, dozens of different proteins comprise the motor that powers the prokaryotic flagellum. The motor has a complicated structure, and its various proteins interact to carry out its function. Based on Darwinʹs explanation for the existence of human eyes, how would he probably have explained the existence of such motors?

#Unit 11. Evolution and Behavior
  1. Because he could not have explained their existence, he would have used supernatural agents as a temporary explanation until the gap in scientific knowledge had been filled.

  2. Because he could not have explained their existence, he would have concluded that the human brain has not (and probably cannot) evolve the capability to solve such complex problems.

  3. He would have proposed that these motors were the products of aliens, and had been delivered to Earth by extraterrestrial visitors.

  4. He would have proposed that less complicated, but still functional, versions (maybe even with a different function) had existed in ancestral prokaryotes.

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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

TLS Online TPP Program

#Question id: 4079

#Unit 3. Fundamental Processes

What is the evidence that pre-mRNAs are not synthesized unless machinery for processing is properly positioned?

TLS Online TPP Program

#Question id: 4080

#Unit 3. Fundamental Processes

How the location of exons and introns within a gene are determined?

TLS Online TPP Program

#Question id: 4081

#Unit 3. Fundamental Processes

Which of the following regulatory scenarios of cell-type-specific expression of fibronectin isoforms in humans is (are) consistent with information on known splicing factors?

a. A Tra-like splicing factor expressed in fibroblasts is required for inclusion of EIIIA and EIIIB exons.

b. An Sxl-like splicing factor is required in hepatocytes for exclusion of EIIIA and EIIIB exons.

c. A Tra-2-like factor enhances binding of the cleavage/polyadenylation complex in fibroblasts.

d. A Dsx-like protein is required to inhibit transcription of the fibronectin gene.

TLS Online TPP Program

#Question id: 4082

#Unit 3. Fundamental Processes

Which of the following is (are) not involved in alternative splicing in eukaryotes?