Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers



  1. In the phase when the cell
    is not dividing (interphase) is
    there activity within the cell
    nucleus?


In the interphase thmetabolic activity in the cell nere is intenseucleus: (^)
DNA is dtranscripteuplicating, d and RNA is produced.euchromatin is being



  1. How are the concepts of
    chromosome, chromatin and
    chromatids related? In which
    phase of the cell cycle does
    DNA duplicate?


Chromatin is a set of filamentous DNA
molecules dforming euchromatin aispersed in the karyoplasmnd
heterochromatin portions. Each


chromatinchromosome filament is a complet(a DNA molecule, oe (^) r
double helix). The chromatin of the
human somaticDNA molecules ( cell is f22 homologousormed by 46
chromosomes and 1 pair of sex
chromosomes).
In interphase the cell prepares itself for
division and duplication omolecules occurs. The duplication off DNA (^)
every DNA DNA double helix bound by a structuremolecule forms two identical
called centromere. In this phase each
identicalcalled chromatid. I chromosomt is also due of these pairs isring the
interphase that the chromatids begin to
condensate assuming shorter shape typical of chromosomethe thicker and
illustrations. So the phase of the cell
cycle in interphase.which DNA duplicates is the
Some Biology textbooks call the
chromosome chromatin as well as tha unique filame condensedent of (^)
structure made of two identical
chromatidsRigorously the pair of identical after the DNA duplication.
chromatids bound in the centromere are
two coand therefore they are pies of the same ctwo identicalhromosome
chromosomes (and not only one).



  1. What is the structure that
    maintains identical chromatids
    bound?
    The structure that maintains identical
    chromatids bound is the centromere.

  2. How is the chromosome
    region where the centromere
    is located called? How are
    chromosomes classified in
    relation to the position of their
    centromere?


The chromosomcentromere is located e region where theis called primary (^)
constriction. In microscopic view this
region is narrmost part of the chromosomower (a stricture) thane.
Accordinconstriction the chromg to the position oosomes aref the primary
classified as telocsubmetacentric or entric, acrocentric,metacentric.
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