Metaphase Plate and Cell Division

[Moonchild]

OK...

 

Chromosomes line up on the metaphase plate. When prokarya divide, their DNA is attached to the inside of their "cell membrane." The point at which a cell fissures is called the cleavage furrow.

 

Based on these givens, is the following possible:

 

The nucleus "disintegrates" during prophase and unfolds to become the metaphase plate during metaphase to which chromosomes "line up" on. Then, the "nucleus plate" divides in half as the cleavage furrow.

 

Is this at all entirely plausible?

[Tormod]

I must admit that this is entirely Greek to me.

[TeleMad]

Moonchild: Chromosomes line up on the metaphase plate. When prokarya divide, their DNA is attached to the inside of their "cell membrane." The point at which a cell fissures is called the cleavage furrow.

 

You're mixing in different concepts. Prokaryotes have only a single circular chromosome (not chromosomes) and they also don't have a metaphase plate. Also, a cleavage furrow occurs in animal cells, but not in plants: cytokinesis occurs in plants by the building up of a cell plate and then a cell wall in the middle of the original cell.

 

Moonchild: Based on these givens, is the following possible:

 

The nucleus "disintegrates" during prophase and unfolds to become the metaphase plate during metaphase to which chromosomes "line up" on. Then, the "nucleus plate" divides in half as the cleavage furrow.

 

Is this at all entirely plausible?

 

In animal cells, the cleavage furrow forms as a ring of contractile proteins (containing actin) begins contracting. It is like taking a microscopic belt and wrapping it around the equator of the cell and then slowly cinching it in, except that the belt it attached to the inside of the membrane and not on the outside.

 

And I can't remember evern reading anything about there being an actual, physical plate in the middle of cell where the chromsomes line up at, and it seems to me that having something like that there would throw a monkeywrench into the working of nuclear division...for example, during meiosis, how would some chromosomes on one side of the plate make it through it to get the other side?

[alxian]

moonchild..

 

i've been trying to design a plant like life form for my novel.. i thought maybe you could offer some input

 

UV energy is corrosive to the bonds that hold dna together right?

 

what if you had a creature that depended on UV for an energy source and who had developed sufficient resistance to UV radiation..

 

what would such a cell look like?

 

is it possible for a creature to have more than two cell membrane layers? like 3 or 4 with an energy metabolizing layer near the surface of the cell and protected behind natural uv blockers the cell nucleus burried within the cell?

 

furthermore do you think its possible to have a creature evolve such cells only on the outside? multi layered cells in the epidermis but normal single layer cells deeper down?

 

it would be like living hair... the outter layer would'nt be totally dead but would be like a leathery bark from which the animal creates complex sugars through the UV interchange with its star and water and minerals and abundant oxygen it would absorb from its environment...

 

would be tough moving around but that leathery layer could be like hair in that it only needs to be in certain areas, sheilding the vulnerable creature from intense UV radiation..

 

any thoughts?