biology mitosis 0.0 / 5 ? ScienceThe human bodyGCSEEdexcel Created by: revisionprodigyCreated on: 03-04-15 19:48 background INFO All chromosomes are found in the nucleus of a cell. The nucleus is surrounded by a membrane called the nuclear envelope. 1 of 7 stage one STAGE ONE. Before mitosis begins, each chromosome duplicates to consist of two strands called chromatids* *each chromatid is long and thin. 2 of 7 stage two STAGE TWO. The choromatids condense- they become shorter, thicker and more visible. They are joined together at the centromere. The nuclear envelope disappears. 3 of 7 stage three STAGE THREE Tiny spindle fibres spread out from each end of the cell and attatch to he centromere of each chromosome. The spindle fibres arrange each chromosome in the centre of the cell. 4 of 7 STAGE FOUR STAGE FOUR the spindle fibres contract, pulling the two chromatids apart a nuclear envelope forms around each new set of chromosomes, and the cell itself starts to divide 5 of 7 stage five STAGE FIVE the cell finishes dividing in two and the chromosomes become longer and thinner both cells are IDENTICAL and contain 46 chormosomes 6 of 7 definition MITOSIS : DIVISION OF A PARENT CELL THAT PRODUCES TWO GENETICALLY IDENTICAL DIPLOID CELLS 7 of 7
Comments
No comments have yet been made