Question

13-2 True or False. Identify each of the following statements as true (T) or false (F). Provide a brief justification for your answer.

(a) The plus end of microtubules and microfilaments is so named because subunits are lost and never added there. (b) Colchicine is an agent that can stop the polymerization of microtubules, intermediate filaments, and microfilaments.

(c) Treating a mitotic cell with Latrunculin A will result in the movement of chromosomes to one side of the cell.

(d) Acidic keratins, vimentin, desmin, and nestins are proteins present in intermediate filaments.

Answer 1

1. False it is the minus end because the alpha tubulin is exposed and has a negative charge. Additionally both loss and addition occurs, just that the rate of loss is greater than the rate of addition.  

2. True colchicine causes depolymerisation of microtubules

3. False treatment of mitotic cell with latrunculin A resits implicate Actin in early interaction with chromosome with spindle fibres and in anaphase Chromosome movements. It delays the sister chromatin separation

4. True - all such as acidic keratin, vimentin, desmin and nestins are present in intermediate filaments