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Chapter 4. CELL REPRODUCTION. CELL DIVISION AND MITOSIS. Cell cycle-every cell has a lifecycle – birth, growth and development and death Length of cycle varies. I P M A T. INTERPHASE. When a cell copies its genetic material (chromosomes) in the nucleus and prepares for cell division.
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Chapter 4 CELL REPRODUCTION
CELL DIVISION AND MITOSIS • Cell cycle-every cell has a lifecycle – birth, growth and development and death • Length of cycle varies
INTERPHASE • When a cell copies its genetic material (chromosomes) in the nucleus and prepares for cell division
PROPHASE • Nuclear membrane disappears • Centrioles move to opposite ends of the cell in an animal cell • Spindle fibers begin to form in animal and plant cells
METAPHASE • Pairs of chromatids line up across from each other (like football line of scrimmage) • Spindle fibers connect to centomere of each pair of chromatids
ANAPHASE • Spindle fibers pull chromosomes to opposite ends of the cell
TELOPHASE • Spindle fibers disappear • Chromosomes become encased in a new nuclear membrane
TELOPHASE • Cell membrane pinches in and the cytoplasm divides for an animal cell and two new identical cells are formed - cytokinesis • In a plant cell a new cell plate forms as the cell divides and will become a new cell wall for the new cells • Process repeats itself
RESULTS OF MITOSIS • Two new, identical cells form from mitosis • Mitosis is for growth and repair of organism
ASEXUAL REPRODUCTION • Only one parent needed • Offspring are identical to the parent • Some plants reproduce by sending out shoots or runners, strawberry plant
ASEXUAL REPRODUCTION • Fission – when one organism divides itself in two • Budding – a new organism grows off the side of the parent and then releases when ready • Regeneration – process of regrowing a lost body part, or forming new, identical organisms from the separated body part – seastar or sponges