mitosis

Question 1

mitosis is important in the life of an organism explain why

Answer 1

growth in cell number
replaces and repairs tissue
genetically identical cells
asexual reproduction/cloning

Question 2

describe behaviour of chromosomes during mitosis and explain how this results in the production of two genetically identical cells

Answer 2

chromosomes shorten/thicken
chromosomes move to equator at spindle
attach to individual spindle fibres
spindle fibres contract and centromere divides
sister chromatids separate move to opposite poles of spindle
each pole receives genetic information
nuclear envelope forms around each group of chromosomes at each pole

Question 3

describe what happens to the chromosomes during each stage of mitosis

Answer 3

prophase- chromosomes condense and become visible
metaphase- move to equator or centre of cell and attach to spindle
anaphase- chromatids separate and centromere divides
telophase- chromosomes uncoil becoming less visible

Question 4

two events which occur during interphase

Answer 4

increase in number of organelles
DNA replication

Question 5

comparing mitosis and meiosis

Answer 5

mitosis- chromosome number remains same (diploid cells produced)
cells produced identical
only one division- 2 cells produced
body cell formation and growth

meiosis- chromosome number halved (haploid cells)
cells produced not identical
two divisions- 4 cells produced
used in gamete formation and reproduction information