Species-specific sperm attraction has been documented in numerous species. In echinoderms, sperm are attracted toward eggs of their species by chemotaxis. Following statements are about chemoattraction-

A. In this process Sperm follows a gradient of a chemical secreted by the egg.

B. These oocytes control only the type of sperm they attract, but not the time at which they attract them.

C. Releasing the chemotactic factor only when the sea urchin egg has completed all of its meiotic divisions .

D. Releasing the chemotactic factor only when the sea urchin egg is in second metaphase of its meiotic division.

E. The mechanisms of chemotaxis differ among species and chemotactic molecules are different even in closely related species.

Which of the following statement are incorrect about this process?

#Question id: 2445

#Unit 2. Cellular Organization

All members of the kinesin family of motor proteins

#Question id: 2446

#Unit 2. Cellular Organization

The dynactin protein complex serves to

a. link vesicles and chromosomes to cytosolic dynein light chains.

b. link axonemal dynein to B tubules.

c. enhance the processivity of cytosolic dynein.

d. mediate microtubule attachment to centrosomes.

e. attach kinesin to vesicles.

#Question id: 2447

#Unit 2. Cellular Organization

In the axonemes, the arrangement of nine outer doublet microtubules, as well as the protofilament number of each outer doublet, is specified by

#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