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Heterochromatin

Heterochromatin

(Science: cell biology, genetics) The chromosomal regions that are condensed during interphase and at the time of nuclear Division.

They show what is considered an abnormal pattern of staining as opposed to euchromatin. Can be subdivided into constitutive regions (present in all cells) and facultative heterochromatin (present in some cells only). The inactive x chromosome of female mammals is an example of facultative heterochromatin.


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Centromeres in a resting nucleus

Please take a look at this statement: Centromeres appear as constitutive heterochromatin in a resting nucleus. Is that true? Does that mean that the centromere sequences have no function in non-dividing cells? So, the centromeres must have sequences which only ...

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by Adz795
Sun Dec 04, 2011 9:55 am
 
Forum: Cell Biology
Topic: Centromeres in a resting nucleus
Replies: 3
Views: 1748

Where are Euchromatin and Heterchromatin found?

"Where are Euchromatin and Heterchromatin found?" - Everywhere... "Is either Euchromatin or Heterochromatin found in the mitochondrial genome?" - Both. Euchromatin - is actively transcribed portion Heterchromatin - inactive, packed portion Most of the time ...

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by Cat
Tue Sep 13, 2011 8:56 pm
 
Forum: Genetics
Topic: Where are Euchromatin and Heterchromatin found?
Replies: 3
Views: 3757

Nucleolus

The nucleous functions as the synthesizer and assembler of rRNA. The nucleolus, just like the rest of the nucleus, contains DNA. The heterochromatin surrounds the nucleolus. I do not know why the nucleolus appears dark in TEMs. I hope this helps.

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by Talcen
Mon Sep 05, 2011 9:30 pm
 
Forum: Cell Biology
Topic: Nucleolus
Replies: 5
Views: 7569

Nucleolus

... that it manufactures the ribosomal subunits. -Why is it that the nucleolus appears very dark in transmission electron micrographs? Does it have heterochromatin? Does it even have DNA? Thanks.

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by Adz795
Mon Sep 05, 2011 2:24 pm
 
Forum: Cell Biology
Topic: Nucleolus
Replies: 5
Views: 7569

Where are Euchromatin and Heterchromatin found?

Is either Euchromatin or Heterochromatin found in the mitochondrial genome? and why? I can't seem to find anything in my reading that states either way. I think it may be heterochromatin, but I am not sure.

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by Lindy
Tue Aug 30, 2011 4:50 pm
 
Forum: Genetics
Topic: Where are Euchromatin and Heterchromatin found?
Replies: 3
Views: 3757
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