Biology Questions and Answers
- Does mitosis properly
occur before or after the
interphase? Is it a mere “point
of view” issue?
Mitosisphase after interphase since must be considered a succeethis is ading
preparation stenot merely a point of view p to mitosis.issue. Thus it is
- Into which periods is
mitosis divided?
Mitosisprophase, m is divided into four periods:etaphase, anaphase and (^)
telophase.
- What are centrioles? In
which type of cell are they
present?
Centrioles are tiny cylindrical structures
made of nine microtubappear in pairs in the cell. Centriolesule triplets. They
participate in the making of
cytoskeleton cell division thand of cilia and flagella. Iney play a role in the
formation of the aster fibers.
Centrioles are structures present in
animal cells, in mostsome primitive fungi. There are no protists and in
centrioles in cells of superior plants and
in general it is considercells do not have centrioled that plantes (although (^)
this is not entirely correct since some
plants have centriole-containing cells).
The region where the centrioles are
located is called thcell. e centrosome of the
- What are the main events
of the first mitotic period?
The first mitotic period is prophase.
During prophase thoccur: migration of each centriole pe following eventsair (^)
(centrioles were duplicated in
interphase) to oformation around the centriole ppposite cell poles; asterairs;
formation of the spindle fibers between
the two cchromosome entriole pcondensation;airs; end of
disintegration of the nucleolus; breaking
of the karyothcondensed chromeca; dispersion oosomes in thef
cytoplasm; binding of chromosomes to
the spindle fibers.
- What is the mitotic
apparatus?
Mitoticfibers, ra apparatusdial structures aro is the set of asterund each (^)
centriole pair, plus the spindle fibers,
fibers that extend across the between the two centriole pairs locatecell (^) d
in opposite cell papparatus appears in prophase aoles. The mitoticnd has (^)
important role in the orientation and
gripping of chromosomcellular elements causing es and otherthem to
separate and migrate to opposite cell
poles.
Substances that disallow the formation
of the mitotica molecule that binds to tu apparatus, like bulincolchicine,
molecules and prevents the synthesis of
microtuColchicine is usbules, interrupt cell division.ed to study
chromosomes since it paralyzes mitosis
when chromso are more easily viewed under theosomes are condensed and
microscope.
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