Biology Questions and Answers
Cell Nucleus
- What are cells with a
delimited nucleus called?
What are the main elements
of the nucleus?
Cells with delimited neukaryotic cells. Organismsucleus are calle composedd (^)
of one or more eukaryotic cellscalled eukaryotes. are
The mains elthe chromatinements of the nucleus ar (made of DNA e
molecules), the nucleolus, the
karyolymnuclear mph, or nucleoplasm,embrane (or karyot and theheca).
- Do all eukaryotic cells have
nucleus and only one nucleus?
There are eukaryoticnucleus and others with more than cells without aone (^)
nucleus. Oresponsible fsteoclasts,or resorptio the cellsn of the (^)
osseous matrix, for example, are
multinucleate cells; striated mfibers are multinucleate too. Red blooduscle (^)
cells are an example of enucleated
specialized cells.
- Of which substances is
chromatin made?
Chromatin is maassociated to proteins called histonde of DNA moleculeses.
- What are heterochromatin
and euchromatin?
Chromatin is uncondensed nuclear DNA,
the typicalinterphase (th DNA more phase ophology inf the cell cycle i (^) n
which the cells is not dividing itself). In
this phase ocan be found as heterochromatin, morf the cell cycle chromatin (^) e
condensed and dark (in electronic
microscopy) pand as euchromatin,ortions o less condensed andf DNA molecules, (^)
lighter portions of DNA molecules.
Since it is uncondensed the euchromatinis the biologically active portion of the
DNA, i.genes to be., the region that has activee transcripted into RNA. The (^)
heterochromatin represents the inactive
portions of the DNA molecule.
- What is the relation
between the concepts of
chromatin and chromosome?
Are euchromatin and
heterochromatin part of
chromosomes?
Every filament ocomplete DNA moleculf chromatine (a com is aplete (^)
double helix), i.chromosome. A DNA mole., a completeecule may f (^) orm
euchromatin and heterochromatin
portions thchromosomes.us both are part of
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