A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island, and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none of them resembles her. There are, instead, several species each of which eats only a certain type of food. None of the species can fly, for their flight wings are absent, and their balancing organs (i.e., halteres) are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap.In each fly species, the entire body segment that gave rise to the original flight wings is missing. The mutation(s) that led to the flightless condition could have

#Question id: 2427

#Unit 2. Cellular Organization

Known functions of actin-binding proteins include

a. severing of long filaments to generate shorter filaments.

b. inhibition of filament polymerization.                   

c. bundling of filaments.

d. acceleration of filament polymerization rates.

e. capping of the (+) end.

#Question id: 2428

#Unit 2. Cellular Organization

Which of the following prevent(s) acting disassembly?

a. cytochalasin D         b. jasplakinolide          c. latrunculin               d. phalloidin

#Question id: 2429

#Unit 2. Cellular Organization

Which of the following statements is (are) true of actin assembly?

a. ADP-actin can assemble into filaments.    

b. Actin (+) ends grow faster than actin (-) ends.

c. ATP-actin can assemble into filaments.

d. Toxins that alter the assembly of actin filaments have been used as tools to study actin in living cells.

#Question id: 2430

#Unit 2. Cellular Organization

Actin-binding proteins that generate actin filament bundles:

#Question id: 2431

#Unit 2. Cellular Organization

Examples of actin cross-linking proteins include

a. fimbrin.        b. dystrophin.  c. α-actinin.     d. spectrin.      e. myosin S1.

#Question id: 2432

#Unit 2. Cellular Organization

Which of the following parts of myosin interact(s) with actin?

a. head             b. neck             c. tail              

d. essential light chain             e. regulatory light chain