All Myosins move toward the (+) end of an actin filament except myosin VI. Myosin VI move toward the (−) end of an actin filament

TLS Online TPP Program

#Id: 1731

#Unit 4. Cell Communication and Cell Signaling

FcεRI signalling through Lyn and Syk kinases also activates E3 ubiquitin ligases, including c-Cbl. Cbl ubiquitinylates Lyn and Syk, as well as FcεRI itself, triggering their degradation.

TLS Online TPP Program

#Id: 9930

#Unit 4. Cell Communication and Cell Signaling

Variation in Influenza Strains

Antigenic variation in HA and NA is generated by

Antigenic drift involves a series of spontaneous point mutations that occur gradually.

Antigenic shift results in the sudden emergence of a new subtype of influenza.

TLS Online TPP Program

#Id: 6055

#Unit 10. Ecological Principles

Taiga, Northern Coniferous Forest, or Boreal Forest  The climate is one of short, cool summers and long winters with abundant snowfall. Precipitation is generally between 40 and 70 cm, often occurring in the form of snow.

Most of the trees are evergreens or conifers with tough needles, hence its similarity to temperate rain forest.

TLS Online TPP Program

#Id: 9706

#Unit 4. Cell Communication and Cell Signaling

Ligand binding to either of the two yeast pheromone GPCRs triggers the exchange of GTP for GDP on the Gα subunit and dissociation of Gα∙GTP from the Gβγ complex.

TLS Online TPP Program

#Id: 8936

#Unit 2. Cellular Organization

When a kinetochore is unattached, the outer kinetochore component Knl1 is phosphorylated by the checkpoint kinase Mps1.