Question

Indicate true (T) and false (F) statements below regarding cytokinesis in animal cells. Choose the correct answer represented by a four-letter string composed of letters T and F only, e.g. TFFF.

( ) The force for cytokinesis is generated by kinesin motors on microtubule bundles that form the contractile ring.

( ) As the contractile ring constricts, its thickness increases to keep a constant volume.

( ) The midbody forms from bundles of actin and myosin II.

( ) Local activation of Ran GTPase triggers the assembly and contraction of the contractile ring.

FTFT

FFTF

FTFF

FFFT

FFFF

I think it's
FFFF

The force for cytokinesis is generated by kinesin motors on microtubule bundles that form the contractile ring.

False; it is generated by actin and myosin

As the contractile ring constricts, its thickness increases to keep a constant volume.

False; it remains constant

The midbody forms from bundles of actin and myosin II.

False; that is true for contractile ring. The midbody is formed from centralspindin, or microtubules

Local activation of Ran GTPase triggers the assembly and contraction of the contractile ring.

False; local activation of RhoA...

Let me know what you guys think.

Answer 1

Answer: Option C- FTFF

1. False

It is generated when movement of myosin II is along actin.

2. True

Since the rate of constriction and ring width are interdependent so, as the ring width increases the rate of constriction proportionally increases with it. This means that to keep the volume constant when ring constricts the thickness increases.

3. False

They are formed by microtubule interacting proteins.

4. False

The assembly is triggered by Rho GTPase activation not Ran.