BIO HELP!!!

[larina]

Assalamo Alaikum.
Here, i got stuck in a part known as Telomere.
I'll be really thankful if someone can tell be something about telomeres.

 

[soumayya]

in which chapter is it..?

 

[soumayya]

it is a length of non-coding DNA located at the ends of a chromosomes which keep the ends of the various chromosomes in the cell from accidentally becoming attached to each other.

 

[larina]

it is in the chapter of cell division.
so during cancers, these telomeres are not present??

 

[jav.ak]

There is an enzyme telomerase, which constantly builds up telomers. It is present in cells which need to divide repeatedly. If certain chemicals or viruses cause other cells to produce telomerase, these cells will start dividing without any limit, leading to the development of cancers.

 

[jav.ak]

@ larina

Telomers are short lengths of non coding DNA, present at the tips of chromosomes. Chromosomes do not replicate right to the end, during mitosis. Therefore, telomers become shorter n shorter each time the cell divides. When the telomers are too short, genes are activated which prevent the cell dividing any more. This limits the number of times that a cell can divide. The mechanism acts as a protection against uncontrolled cell division which can produce cancer.

 

[larina]

thanks soumayya and jav.ak!
hmm..sorry for asking one more thing :roll:
@jav.ak... as you said that the as the telomeres become shorter, genes are activated which prevents further cell division, so a hair(for example) will not grow after the telomeres of its chromosomes become shorter?

 

[jav.ak]

np

yea i guess.... if cells in hair do not produce telomerase. =/

 

[jav.ak]

hair on our body like on arms do not produce telomerase, obviously! cuz they can grow to a certain length.

 

[larina]

but what about the hair on our scalp??

 

[jav.ak]

idk =s may be its growth slows down =/



As v get older, our telomers get shorter and this is thought to be one of the factors responsible for the ageing of our bodies. thats y our height stops increasing after 20

 

[larina]

u said that telomerase is an enzyme that builds up telomeres....which means that cell division IS taking place but at normal rate(not repeatedly)..
--->during cancers, does the telomere dissapear or what??
sorry for asking alot :| u can help me out

 

[jav.ak]

np
no telomers do not get disapeared.


a virus or chemical can cause a cell to produce telomerase enzyme. this enzyme constantly rebuilds the telomers. so the cells start to divide without any limit.
The uncontrolled cell division causes tumors to develop. This is cancer

 

[larina]

thanks jav.ak

 

[jav.ak]

ur welcm