Which type of molecules bind to myosin head during the skeletal muscle contraction?

#Question id: 5144

#Unit 5. Developmental Biology

Following statements regarding to noncanonical wnt pathways.

A. The planar cell polarity, or PCP, pathway functions to regulate the actin and microtubule cytoskeleton, thus influencing cell shape, and often results in bipolar protrusive behaviors necessary for a cell to migrate.

B. Wnts (such as Wnt5a and Wnt11) can activate Disheveled by binding to a different receptor (Frizzled paired with Ror instead of Lrp5), and this Ror receptor complex phosphorylates Disheveled in a way that allows it to interact with Rho GTPases.

C. Wnt/PCP signaling through cytoskeleton control can direct cells to divide in the different plane ( forming upper and lower tissue compartments) and to move within that different plane.

D. the Wnt/calcium pathway leads to the release of calcium stored within cells, and this released calcium acts as an important secondary messenger to activates a phospholipase (PLC) whose enzyme activities release a compound that in turn releases calcium ions from the cytosol.

Which of the following is incorrect?

#Question id: 11332

#Unit 10. Ecological Principles

The most plausible hypothesis to explain why species richness is higher in tropical than in temperate regions is that

 A) tropical communities are older.

 B) tropical regions generally have more available water and higher levels of solar radiation.

 C) higher temperatures cause more rapid speciation.

 D) diversity increases as evapotranspiration decreases.

#Question id: 24204

#Unit 4. Cell Communication and Cell Signaling

#Question id: 2789

#Unit 2. Cellular Organization

All of the following can be found in chromatin except

#Question id: 11319

#Unit 10. Ecological Principles

Which of the following plant defensive compounds is found at high levels in oak leaves?