White-breasted nuthatches and Downy woodpeckers both eat insects that hide in the furrows of bark in hardwood trees. The Downy woodpecker searches for insects by hunting from the bottom of the tree trunk to the top, while the White-breasted nuthatch searches from the top of the trunk down. These hunting behaviours best illustrate which of the following ecological concepts?

#Question id: 2154

#Unit 2. Cellular Organization

Membrane lipids are distributed appropriately between the two leaflets of a given membrane by

a. dockases.    

b. trumpases.              

c. fatty acid desaturases.        

d. flippases.    

e. transmembrane tunnelases.

#Question id: 2155

#Unit 2. Cellular Organization

Cholesterol is

a. unrelated to any plant lipids.                     

b. not found in chloroplast membranes.

c. encoded by an intron-containing gene on chromosome 23.

d. relatively abundant in the plasma membrane and endocytic membranes.

e. synthesized in the ER.

#Question id: 2156

#Unit 2. Cellular Organization

Proteins known to be involved in Golgi apparatus independent transport of lipids include

a. StAR protein.                                 

b. Neimann-Pick C1 (NPC1) protein.

c. HMG CoA reductase.                    

d. acyl:cholesterol acyl transferase (ACAT).

e. cholesterol 7α-hydroxylase.  

#Question id: 2157

#Unit 2. Cellular Organization

Which of the following is not a metabolic derivative of cholesterol?

a. dolichol                  

b. vitamin D               

c. bile acids    

d. v-SNARE molecules                     

e. NSF

#Question id: 2158

#Unit 2. Cellular Organization

Which of the following factors increase(s) the rate of simple (passive) diffusion of a solute across a phospholipid bilayer?

#Question id: 2159

#Unit 2. Cellular Organization

A channel protein