The Galapagos finches were an important clue to Darwin's thinking about the origin of species. These finches are believed to have descended from a single ancestral species that colonized the Galapagos archipelago, America, over a short period of time. The Galapagos finches differ in their beak shape and size. Different species feed on seeds that vary in size and hardness. Which of the following is the most likely explanation for these patterns?

#Question id: 2448

#Unit 2. Cellular Organization

Axonemal dynein

a. may contain two or three head domains.

b. attaches to a B tubule through its base domain.

c. consists of heavy, intermediate and light chains.

d. is a (-) end-directed motor.            

e. is an ATPase.

#Question id: 2449

#Unit 2. Cellular Organization

What is the correct order of the stages of mitosis?

a. anaphase               

 b. metaphase              

c. telophase    

d. prophase                 

e. prometaphase

#Question id: 2450

#Unit 2. Cellular Organization

Which of the following contribute(s) to pole separation during anaphase B?

a. cytosolic dynein     

b. a (-) end-directed kinesin               

c. CENP-E                     

d. microtubule depolymerisation                   

e. microtubule polymerization

#Question id: 2451

#Unit 2. Cellular Organization

The average lifetime of microtubules during mitosis is

#Question id: 2452

#Unit 2. Cellular Organization

Intermediate filaments

a. are typically 6 nm in diameter.                  

b. are essential for cell motility.

c. may be used to diagnose the tissue of origin for many cancers.

d. are composed of globular subunits.                       

e. are formed from tetrameric subunits.

#Question id: 2453

#Unit 2. Cellular Organization

Keratins

a. are found in the nucleus.                            

b. are typically expressed in neuronal cells.

c. contain an acidic and a basic subunit.                    

d. function in cell adhesion.

e. are the major proteins of hair and horns.