If it were possible to conduct sophisticated microscopic and chemical analyses of microfossils found in 3.2-billion-year-old stromatolites, then within such microfossils, one should be surprised to observe evidence of:

I. double-stranded DNA

II. a nuclear envelope

III. a nucleoid

IV. a nucleolus

V. nucleic acids

#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.