CELL DIVISION MITOSIS and the Cell Cycle MITOSIS and the Cell Cycle.
-
Upload
doris-sherman -
Category
Documents
-
view
230 -
download
3
description
Transcript of CELL DIVISION MITOSIS and the Cell Cycle MITOSIS and the Cell Cycle.
CELL DIVISIONCELL DIVISION
MITOSIS MITOSIS and the and the Cell Cell CycleCycle
MITOSISMITOSIS Mitosis is the process used by most cells to Mitosis is the process used by most cells to
reproduce. reproduce. Asexual ReproductionAsexual Reproduction: only : only needing one parentneeding one parent
During Mitosis, During Mitosis, the cell makes an exact the cell makes an exact copy of itself and its genetic materialcopy of itself and its genetic material
This genetic material is sometimes referred This genetic material is sometimes referred to as the to as the genesgenes or or DNADNA ( (deoxyribonucelic deoxyribonucelic acidacid) of the cell.) of the cell.
The genes are found on the The genes are found on the chromosomeschromosomes of the cell, of the cell, located inside the nucleus.located inside the nucleus.
Mitosis occurs in many stages, Mitosis occurs in many stages, called “called “phasesphases”…”…
INTERPHASEINTERPHASE This is the first This is the first
phase…phase… The cell is The cell is
preparingpreparing for for MitosisMitosis
Chromosomes Chromosomes duplicate duplicate themselves.themselves.
Cell begins to growCell begins to grow..
PROPHASEPROPHASE This is the second phase of This is the second phase of
Mitosis…Mitosis… The nuclear The nuclear
membrane membrane disappears.disappears.
Chromosomes form Chromosomes form and appear and appear “tangled.”“tangled.”
Spindle fibers form Spindle fibers form and attach to the and attach to the chromosomes.chromosomes.
METAPHASEMETAPHASE The third phase of The third phase of
Mitosis.Mitosis.
Fibers pull on Fibers pull on doubled doubled chromosomeschromosomes
Chromosomes “line Chromosomes “line up” in the middle of up” in the middle of the cell.the cell.
ANAPHASEANAPHASE
This is the fourth phase of Mitosis.This is the fourth phase of Mitosis.
Chromosomes are being pulled apartChromosomes are being pulled apart
Chromosomes move to opposite ends of the cell Chromosomes move to opposite ends of the cell just before separation occurs.just before separation occurs.
TELOPHASETELOPHASE Fifth and final Fifth and final
phase of Mitosis.phase of Mitosis. Spindle fibers Spindle fibers
disappear.disappear. Nuclear membrane Nuclear membrane
forms around each forms around each set of chromosomes.set of chromosomes.
2 new cells are 2 new cells are formedformed
MITOSIS MOVIEMITOSIS MOVIE
Microscopic Cells Showing MitosisMicroscopic Cells Showing Mitosis
MEIOSISMEIOSIS
What is MEIOSIS????What is MEIOSIS???? MEIOSIS is a special kind of cell MEIOSIS is a special kind of cell
division that is needed for sexual division that is needed for sexual reproduction.reproduction.
Meiosis creates Meiosis creates egg cellsegg cells in females and in females and sperm cellssperm cells in males. in males.
Meiosis DiagramMeiosis Diagram
HOW DOES THIS WORK???HOW DOES THIS WORK??? Each of you started off as a fertilized egg (2n)Each of you started off as a fertilized egg (2n) ½ of your DNA came from mom’s egg and the other ½ of ½ of your DNA came from mom’s egg and the other ½ of
your DNA came from dad’s spermyour DNA came from dad’s sperm 1n (mom) + 1n (dad) = 2n (you!)1n (mom) + 1n (dad) = 2n (you!) MEIOSIS is a special kind of cell reproduction that produces MEIOSIS is a special kind of cell reproduction that produces
(a single set of chromosomes)sperm and egg cells(a single set of chromosomes)sperm and egg cells
MEIOSIS is Mitosis, only TWICE!MEIOSIS is Mitosis, only TWICE!
Has all the same phases as Mitosis… Has all the same phases as Mitosis… Interphase, Prophase, Metaphase, Anaphase Interphase, Prophase, Metaphase, Anaphase and Telophase…and Telophase…
Meiosis 1Meiosis 1 produces two new cells produces two new cells Meiosis 2Meiosis 2 splits those two cells into four new splits those two cells into four new
cells with only a single set of chromosomes.cells with only a single set of chromosomes.
IMPORTANT DIFFERENCES…IMPORTANT DIFFERENCES… Only Cells that become Only Cells that become gametesgametes (eggs or sperm) (eggs or sperm)
undergo meiosis.undergo meiosis. Cells that undergo meiosis go through two cell Cells that undergo meiosis go through two cell
divisions, so one cell becomes 4 cells in the end…divisions, so one cell becomes 4 cells in the end… Meiosis makes haploid (single set of chromosomes) Meiosis makes haploid (single set of chromosomes)
cells, while Mitosis makes diploid (full set of cells, while Mitosis makes diploid (full set of chromosomes) cells.chromosomes) cells.
Cells which undergo Mitosis are EXACT COPIES of Cells which undergo Mitosis are EXACT COPIES of the original cell. Cells then undergo Meiosis then get the original cell. Cells then undergo Meiosis then get sperm and egg cells.sperm and egg cells.
Meiosis MovieMeiosis Movie
Diagram of Mitosis and MeiosisDiagram of Mitosis and Meiosis
Mitosis PictureMitosis Picture
Meiosis PictureMeiosis Picture
Comparison DiagramComparison Diagram