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N5 Biology Cell Biology subunit 3 DNA and Making New Cells. Making New Cells. simple cell division diagram. nucleus. nucleus. membrane. membrane. nucleus. nucleus. nucleus. 23. 4. 27. 9. Duplicated chromosome. centomere. chromatids. Stages of Mitosis.
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Making New Cells simple cell division diagram nucleus nucleus membrane membrane nucleus nucleus nucleus
23 4 27 9
Duplicated chromosome centomere chromatids
Stages of Mitosis Click here for mitosis animationhttp://www.cellsalive.com/mitosis.htm
More Mitosis Animations Click here for Time lapse film of mitosis (1.30 mins) http://www.bbc.co.uk/learningzone/clips/cell-division-by-mitosis/4189.html Click here for you Tube video (10 mins) http://www.youtube.com/watch?feature=player_embedded&v=L0k-enzoeOM#!
Stages of Mitosis text from pupil booklet When the chromosomes become visible they appear as double threads called chromatids joined by a centromere. Structures in the cell called centrioles migrate to opposite ends of the cell - the ‘north and south poles’. The membrane round the nucleus disintegrates and the chromosomes line up along the equator – in between the north and south poles. Spindle fibres from the centrioles attach to the centromere of each chromosome. The spindle fibres shorten and pull the chromatids apart. One chromatid from each pair moves to the north pole and the other one moves to the south pole. Two new nuclei form when the nuclear membrane forms round each set of chromatids – now called chromosomes. The cell then divides in two
Looking at Dividing Cells You may see some cells under the microscope like some of the cells below
Cell production Click here for film showing how new skin cells are grown (3.09 mins) http://www.bbc.co.uk/learningzone/clips/growing-new-skin-cells/111.html Click here to see a Youtube film of AsepticTechniques while transferring culture medium from a bottle to an agar plate (only watch from start to 6 mins)http://www.youtube.com/watch?v=gQvZ4opDcno&feature=player_embedded
Aseptic Technique • sterilise equipment • remove microorganisms from skin • prevent entry of unwanted microbes • destroy unwanted microbes on wire • prevent entry OR exit of microbes from agar • kill microbes on work area
DNA and Genes A determines an organisms characteristics. Genes are found on . Chromosomes are found in the of all cells. Chromosomes are threadlike structures made from . gene chromosomes nuclei DNA gene DNA nuclei chromosomes
DNA Structure deoxyribose sugar weak hydrogen bond phosphate base nucleotide strong chemical bond double stranded DNA
Click here for website with template and instructions for origami DNA model http://www.dnai.org/teacherguide/guide.html Finished product should look like this
DNA discovery Click here for Youtube video http://www.youtube.com/watch?v=7yE3Z5f-7i0&feature=player_embedded#! DNA: The secret of life, a programme about the race to uncover the structure of DNA. Contains interviews from the scientists involved in the discovery (53mins) Click here for DNA Timeline Activity http://www.dnai.org/teacherguide/guide.html