Cell division Mitosisequational division lecture3

>> YOUR LINK HERE: ___ http://youtube.com/watch?v=LRUaQKH6xh0

Mitosis-equational division • It is divided into two main stages that is:- • 1-karyokinesis -division of nucleus • 2-cytokinesis- division of cytoplasm • Prophase, (pro : first) • (1) Chromosomes becomes short and thick and are clearly distinct inside the nucleus. • (2) Each chromosome has already duplicated (generated a copy of it)form two chromatids. • (3) The two sister chromatids remain attached to each other by centromere. • (4) The centrosome (in animal cell) splits into two with simultaneous duplication of the centrioles .The daughter centrioles move apart towards the opposite poles. • (5)Spindle fibres are formed between the centrioles. • (6)The nuclear membrane and the nucleolus disappears. • (7) The chromosomes start moving towards an the towards the equatorial plane of the cell. • Metaphase • (1) the chromosomes are attached to the spindle fibre through centromere. • (2) the chromosome moves towards the equatorial plane. • Anaphase • The centromere attaching the two chromatids divides and the two sister chromatids of each chromosome separate and are drawn apart to move towards opposite poles due to the contraction of spindle fibres. • (iv) TELOPHASE • (1)Two sets of daughter chromosomes reach opposite poles. • (3)Spindle fibres disappear. • (4)Chromatids thin out in the form of chromatin fibres. • (5)Nuclear membrane is formed. • (6)The cleavage furrow starts deepening in the animal cell. • (7)Nucleoli reappear, • CYTOKINESIS • (Division of cytoplasm) • • Cleavage furrow deepens totally in ANIMAL CELL and separates the two daughter cell (centripetal type) • -cell plate formation takes place which is directed from inside to outside in the case of plant cell(centrifugal type) • Picture credit:https://www.freepik.com

#############################

New on site