350 likes | 508 Views
Cell Cycle Steps to Mitosis. Types of Cells Review. Prokaryotes – No nucleus OR membrane bound organelles Examples: Bacteria Eukaryotes – Has a nucleus AND membrane bound organelles Examples: Plants and animals. Prokaryotes. Prokaryotes – Lack nucleus Has a single chromosome
E N D
Types of Cells Review • Prokaryotes – No nucleus OR membrane bound organelles • Examples: Bacteria • Eukaryotes – Has a nucleus AND membrane bound organelles • Examples: Plants and animals
Prokaryotes • Prokaryotes – • Lack nucleus • Has a single chromosome • Reproduces by binary fission • Includes bacteria
What is binary fission? Type of reproduction used by bacteria Cells increase their cell mass slightly DNA and cell components are replicated Each cell divides into 2 daughter cells
Eukaryotes Contains a nucleus and membrane bound organelles Asexually reproduce cells by a process called mitosis
2 Reasons why cells divide DNA OVERLOAD 1. _____________________As cell grows bigger demand on DNA“genetic library” becomes too great Ex: Small town library has 1000 books. As town grows and more people borrow books, there may be a waiting list to read the most popular titles http://www.adc.state.az.us/images/Off-Library.JPG
2 Reasons why cells divide 2. _____________________As cell grows bigger demand for transport across membrane is too great Material exchange can’t keep up
More on Why Cells Divide Ability to transport of oxygen, food, waste across cell membrane depends on _______________ Need for these depends on ___________ SURFACE AREA CELL VOLUME As cell grows these DON’T increase at the same rate Surface-Area to Volume Ratio Animation
Ratio of Surface Area to Volume in Cells Cell Size Surface Area (length x width x 6) Volume (length x width x height) Ratio of Surface Area to Volume
BIGGER CELLS NEED MORE FOOD and OXYGEN, but CAN’T TRANSPORT IT FAST ENOUGH or IN BIG ENOUGH QUANTITIES! http://www.animationlibrary.com
Image from: http://www.bcps.org/offices/lis/models/life/images/grow.JPG Image by Riedell Multicellular organisms grow mainly by increasing cell number
DNA CAN BE: SPREAD OUT INNON-DIVIDING CELLS SCRUNCHED UP IN DIVIDINGCELLS CHROMOSOMES CHROMATIN
DNA in PROKARYOTES • BACTERIAL DNA is CIRCULAR • HAVE ONE CHROMOSOME • NO NUCLEUS; ATTACHED TO CELL MEMBRANE http://www.origin-life.gr.jp/3202/3202121/fig6.jpg
DNA in EUKARYOTES(Plants & Animals) • DNA is ROD-SHAPED CHROMOSOMES • MANY PAIRS • FOUND IN NUCLEUS http://cellbio.utmb.edu/cellbio/chrom2.jpg
Chromosome structure SISTER CHROMATIDS • ___________________2 identical arms • __________________ constricted area holds chromatids together CENTROMERE HOMOLOGOUS • __________________ PAIR • 2 of each chromosome(one from mom; one from dad)
HOMOLOGOUS CHROMOSOMES • SAME SIZE • SAME SHAPE • CARRY GENES for the SAME TRAITS • BUT ______________! (Don’t have to have the SAME CHOICES) NOT IDENTICAL http://arnica.csustan.edu/biol3020/cell_division/cell_division.htm http://sps.k12.ar.us/massengale/genetics%20tutorial.htm
CELL DIVISION in PROKARYOTES BINARY FISSION Bacteria reproduce using __________________________________ http://fig.cox.miami.edu/~cmallery/150/mitosis/fission.jpg
Cell Cycle __________=series of events that cells go through as they grow and develop
Cell Cycle Stages in growth & division G1 Phase (Gap 1) S Phase (Synthesis) G2 Phase (Gap 2) M Phase (Mitosis) Cytokinesis
CELL CYCLE INTERPHASE – non-dividing phase G1- Grow bigger Cell is “doing its job” DNA is spread out as chromatin S - Synthesis (copy DNA) & chromosomal proteins G2- Grow bigger, make organelles & molecules needed for cell division
CELL DIVISION MITOSIS – Nuclear division Prophase Metaphase Anaphase Telophase Cytokinesis – Cytoplasm divides G0 – cell stops dividing (Ex: nerve cell)
Life Cycle of A Cell Mitosis has no beginning and no end
Stages of MitosisInterphase – “Resting Phase” Cells carrying on normal activities Chromosomes are not visible Cell metabolism is occurring Occurs before mitosis
Pearson Education Inc publishing as Pearson Prentice Hall PROPHASE 1st dividing phase http://www.life.uiuc.edu/plantbio/102/lectures/08mit&veg102.html DNA scrunches into chromosomes Centrioles appear in centrosome region & move to poles Nuclear membrane & nucleolus disappear Spindle fibersform & attach to chromosomes
CENTROSOME ________ region organizes spindle Spindle MICROTUBULES are part of cytoskeleton http://www.coleharbourhigh.ednet.ns.ca/library/organelle_worksheet.htm
middle Chromosomes line up in ___________ METAPHASE Images from:Pearson Eduction Ince; Publishing as Pearson Prentice Hall http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0247.JPG
Centromeres splitCentrioles pull chromatids_______ apart ANAPHASE Images from:Pearson Eduction Ince; Publishing as Pearson Prentice Hall http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0247.JPG
two See ______ nuclei Nuclear membrane & nucleolus return TELOPHASE (reverse prophase steps) Chromosomes spread out as chromatin Centrioles disappear Spindle fibers disappear Images from:Pearson Eduction Ince; Publishing as Pearson Prentice Hall http://www2.bc.cc.ca.us/cnewton/Biology%2011/Mitosis.html
CYTOKINESIS Cytoplasm splits into 2cells ANIMAL CELLS pinch cytoplasm in two with a ______________________ CLEAVAGE FURROW
CYTOKINESIS Cytoplasm splits into 2 cells PLANT CELLS can’t pinch because they have a sturdy ____________ Plant cells separate cytoplasm by growing a _______________ down the middle. CELL WALL CELL PLATE http://www.eastcentral.edu/acad/depts/BI/plant_mitosis_nolabels.html
Mitosis Fun Mr. Parr's Version - Mitosis Song Mitosis Animation Mitosis Animation - Via YouTube
Concept Map Cell Cycle includes is divided into is divided into
M phase (Mitosis) Interphase G1 phase S phase G2 phase Prophase Metaphase Anaphase Telophase Concept Map Section 10-2 Cell Cycle includes is divided into is divided into