centrosome

Examples of centrosome in the following topics:

• Interphase

  • The centrosome is duplicated during the S phase.
  • The two centrosomes will give rise to the mitotic spindle, the apparatus that orchestrates the movement of chromosomes during mitosis.
  • At the center of each animal cell, the centrosomes of animal cells are associated with a pair of rod-like objects, the centrioles, which are at right angles to each other.
  • Centrioles are not present in the centrosomes of other eukaryotic species, such as plants and most fungi.

• Comparing Plant and Animal Cells

  • While both animal and plant cells have microtubule organizing centers (MTOCs), animal cells also have centrioles associated with the MTOC: a complex called the centrosome.
  • Animal cells each have a centrosome and lysosomes, whereas plant cells do not.
  • The centrosome is a microtubule-organizing center found near the nuclei of animal cells.
  • However, the exact function of the centrioles in cell division isn't clear, because cells that have had the centrosome removed can still divide; and plant cells, which lack centrosomes, are capable of cell division.
  • The centrosome consists of two centrioles that lie at right angles to each other.

• Intermediate Filaments and Microtubules

  • Microtubules are also the structural elements of flagella, cilia, and centrioles (the latter are the two perpendicular bodies of the centrosome).
  • In animal cells, the centrosome is the microtubule-organizing center.

• Characteristics of Eukaryotic Cells

  • Animal cells have a centrosome and lysosomes, whereas plant cells do not.
  • The centrosome is a microtubule-organizing center found near the nuclei of animal cells while lysosomes take care of the cell's digestive process.
  • Despite their fundamental similarities, there are some striking differences between animal and plant cells.Animal cells have centrioles, centrosomes, and lysosomes, whereas plant cells do not.

• The Mitotic Phase and the G0 Phase

  • The nucleolus disappears and the centrosomes begin to move to opposite poles of the cell.
  • Microtubules that will eventually form the mitotic spindle extend between the centrosomes, pushing them farther apart as the microtubule fibers lengthen.
  • Each chromatid, now called a chromosome, is pulled rapidly toward the centrosome to which its microtubule is attached.

• Meiosis I

  • The centrosomes, which are the structures that organize the microtubules of the meiotic spindle, also replicate.
  • Microtubules grow from centrosomes placed at opposite poles of the cell.

• Meiosis II

  • The centrosomes that were duplicated during interphase I move away from each other toward opposite poles and new spindles are formed.