describe a major structural or functional barrier a cell must must over -come in order to divide.

Question

describe a major structural or functional barrier a cell must must over -come in order to divide.

Answer 1

Hi Theman,

 

Cells have an intrinsic ability to undergo certain number of divisions, this comes from the tissues as well as genome. For instance, skin cells divide indefinitely to repair the skin wounds but heart cells or cardiac cells do not.

 

Cells in organism and cells in culture both have limited division potential.

 

As number of divisions proceed, cells age in the same way as we age. When they cannot divide any further then they enter a stage called: senescence. Senescent cells do not divide further

 

There are multiple biochemical factors that lead to senescence. These include depletion of proteins that participate in cell-division. If a depleted protein is supplied from outside (through growing medium in cell culture and through therapy in patients) then cell would divide again. This is overcoming a functional barrier to cell division.

 

Cell chromosomes have to arrange in a particular manner for cell division to proceed. Sometimes chromosome are too damaged (through UV, X-Rays, other chemical damage) to retain their integrity. Normal DNA repair enzymes in cells have failed to repair the damage. In that case sometimes, DNA repair can be induced through extrinsic factors that stimulate alternate enzymes and pathways. This is overcoming a structural barrier.

 

Hope this helps.

Answer 2

Functional: Functional barriers refer to the ability of the cell to work and do its job:

There must be enough genetic material for 2 cells.

Organelles must also be divided.

 

Structural: Structural barriers refer to the cell parts:

The genetic material is protected inside the nuclear membrane. How does it get out?

Size issue: If a cell divides; cutting itself into 2; and the next generation does the same, the cells will get smaller and smaller. At some point, the cell must grow before it divides.

 

 

source: http://www.stemmom.org/2013_11_01_archive.html