Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 55348
TLS Online TPP Program

#Question id: 1260

Which of the following statement regarding RTK/Ras pathway is incorrect?

#Unit 4. Cell Communication and Cell Signaling

  1. Receptor activation leads to re-localization of Sos from the cytosol to the membrane, which brings Sos close to its substrate, Ras∙GDP, which is already bound to the plasma membrane by means of a covalently attached lipid.

  2. Binding of Sos to Ras∙GDP leads to conformational changes in the switch I and switch II segments of Ras, thereby opening the binding pocket for GDP so it can diffuse out.

  3. The SH2 domains in GRB2 selectively bind to proline-rich sequences in Sos; different SH3 domains in other proteins bind to proline-rich sequences distinct from those in Sos.

  4. Ras is activated by the exchange of GDP for GTP. Active Ras∙GTP binds to the N-terminal regulatory domain of Raf, a serine/threonine kinase, thereby activating its kinase activity.

More Questions
TLS Online TPP Program

#Question id: 4708

#Unit 11. Evolution and Behavior

The following questions refer to the figure below, which shows an outcrop of sedimentary rock whose strata are labeled A-D. If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?
TLS Online TPP Program

#Question id: 4707

#Unit 11. Evolution and Behavior

For which one of the following observations were both Lamarck's hypothesis and Darwin's hypothesis in complete agreement?
TLS Online TPP Program

#Question id: 4706

#Unit 11. Evolution and Behavior

Which of the following statements best explains why modification or change in an organ or tissue during the lifetime of an individual is not inherited?
TLS Online TPP Program

#Question id: 4705

#Unit 11. Evolution and Behavior

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it ________.
TLS Online TPP Program

#Question id: 4704

#Unit 11. Evolution and Behavior

About thirteen different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the thirteen species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction?
TLS Online TPP Program

#Question id: 4702

#Unit 11. Evolution and Behavior

Which of the following is correct match?