O Levels Biology Cell Division

Chai Hao Wei (17) 311 Biology Chapter 18: Cell Division harvest-tide: abiding growth in size accompanied by electric cell particle and differentiation Mitosis: Cell division during growth * Growth in plants restricted to emergence dits: shoot and root tips A nuclear division such that the daughter nuclei produced contain the said(prenominal) number of chromosomes as the stir nucleus * Non-dividing stage of a cell (still absorb nutrients and build protoplasm) * Chromosomes attend as immense thin locomote called chromatin which cannot be distinguished separately * Centrioles in animal cells divide and chromatin threads bend Interphase nuclear envelope centrioles chromatin cytoplasm Zygote cells enquire to be genetically stalls for the embryo to develop principlely. take of Chromatin Threads 1. Two similar chromatin threads produced drum roll and shorten to become chromosomes 2. each(prenominal) chro mosome consists of two same DNA molecules called sister chromatids. 3. Chromatids joined at a point called centromere.

Cancer : un controlled division of cells * Mistakes in DNA replication or mitosis * Cells lose the ability to control the way they divide and normal functions Asters Centrioles Prophase Chromatin threads condense, coil and shorten to become chromosomes. from each one chromosome consists of two sister chromatids affiliated at the centromere. The chromosomes be promptly visible under a microscope. sister chromatids (one chromosome) centromere new-made prophase: * Nuclear Envelope disintegrates ! * Spindle readys with arbor fibres extending from one celestial pole of the cell to the other In animal cells: * Structures called asters(made up of microtubules) form around centrioles * Centrioles move apart to opposite ends of cells Microtubules are blank protein structures found in cytoplasm of cells. They provide morphologic jump and help to move substances within the cell. Spindle Fibres forming...If you expect to write down a full essay, order it on our website: OrderCustomPaper.com

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