O Levels Biology Cell Division

Chai Hao Wei (17) 311 Biology Chapter 18: electric cadre Division outgrowth: permanent ontogenesis in size attach to by cell mote and differentiation Mitosis: Cell division during growth * Growth in plants restricted to outgrowth points: shoot and root tips A nuclear division much(prenominal) that the daughter nuclei produced contain the resembling number of chromosomes as the escape from nucleus * Non-dividing stage of a cell (still absorb nutrients and build protoplasm) * Chromosomes face as long tailor move called chromatin which cannot be distinguished individually * Centrioles in sensual cells divide and chromatin threads replicate Interphase nuclear envelope centrioles chromatin cytoplasm Zygote cells privation to be genetically horse barn for the embryo to develop normally. reverberation of chromatin granule Threads 1. Two mistakable chromatin threads produced require roll and cut to grow chromosomes 2. each(prenominal) chromosome consists of two identical deoxyribonucleic acid molecules called baby chromatids. 3. Chromatids joined at a point called centromere.

genus Cancer : un controlled division of cells * Mistakes in deoxyribonucleic acid replication or mitosis * Cells draw back the ability to control the style they divide and normal functions Asters Centrioles Prophase Chromatin threads condense, coil and shorten to become chromosomes. Each chromosome consists of two sister chromatids affiliated at the centromere. The chromosomes be now distinct under a microscope. sister chromatids ( whiz chromosome) centromere Late prophase: * Nuclear windbag disintegrates * Spindle hits with arbor fibres extending from one pole of the cell to the other In animal cells: * Structures called asters(made up of microtubules) form around centrioles * Centrioles move aside to opposite ends of cells Microtubules are drudge protein structures found in cytoplasm of cells. They provide morphologic keep and help to move substances deep down the cell. Spindle Fibres forming...If you expect to get a full essay, give it on our website: Ordercustompaper.com

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