1.5a The cytoskeleton and cell division

Question 1

Cytoskeleton definition

Answer 1

Is a complex network of protein filaments that gives mechanical support and shape to cells.
It consists of different protein structures including microtubules, which are found in all eukaryotic cells.

Question 2

Microtubules

Answer 2

Are hollow cylinders composed of the protein tubulin. They radiate (diverge or spread from) from the microtubule organising centre (MTOC) or centrosome.

Microtubules control the movement of membrane-bound organelles and chromosomes.

Question 3

Cell division

Answer 3

Cell division requires remodelling of the cytoskeleton.

Microtubules form the spindle fibres that are active during cell division.

Question 4

Formation and breakdown of microtubules.

Answer 4

The formation and breakdown of microtubules involves polymerisation and depolymerisation of tubulin.