THE CELL CYCLE AND CELL DIVISION
Presented by:
Fasama Hilton Kollie
Lecturer, Department of Biology
Mother Patern College of Health Sciences
CHAPTER OUTLINE
1. Cell Division
2. Importance of Cell Division
3. Prokaryotic and Eukaryotic Cell Division
4. Cell Cycle
5. Regulation of the Cell Cycle
LESSON OBJECTIVES
• By the end of this session, the learners will be able to;
1. Define cell division and cell cycle
2. Identify the purpose of cell division
3. Describe cell division in prokaryotic and Eukaryotic
cell
4. Describe the cell cycle
CELL DIVISION
• It’s the process by which a cell divides to form two new
cells
• Three types of cell division or cell reproduction in
organism
• Prokaryotes (bacteria)
— Binary fission
• Divides forming two new identical cells
 Eukaryotes
— Mitosis
• Cell or organism growth
• Replacement or repair of damaged cells
— Meiosis
• formation of sex cells, or gametes
WHY DO CELLS DIVIDE?
• Cells divide for growth, development, repair of worn-out tissues
and reproduction
• To facilitate the exchange of materials
• To control DNA overloading
PROKARYOTIC CELL DIVISION
1. Binary Fission
• Three (3) major steps;
• DNA Replication
DNA is copied resulting into two identical chromosomes
• Chromosome Segregation
Chromosomes separate and move towards ends (poles) of cell
• Cytokinesis (Separation)
Cytoplasm divides forming two (2) cells
• Each new daughter cell is Genetically Identical to parent cell
Prokaryotic Cell
Division
EUKARYOTIC CELL DIVISION
• Cell division that results in two daughter cells each having the same
number and kind of chromosomes as the parent cell
1. MITOSIS
• Two (2) main steps:
1. Mitosis
Fours steps; [Prophase>Metaphase>Anaphase>Telophase]
2. Cytokinesis
Cytoplasm divides forming two new daughter cells
• Each daughter cell is Genetically Identical to parent cell
Eukaryotic Cell Division Cont.
• Cell division that results in four daughter cells
2. MEIOSIS
• Two (2) major steps:
1. Mitosis
Fours steps; [Prophase>Metaphase>Anaphase>Telophase]
2. Cytokinesis
Cytoplasm divides forming two new daughter cells
• Each daughter cell is NOT Genetically Identical to parent cell
CELL CYCLE
THE CELL CYCLE
• The sequence of events from the time a cell first arises as a result of cell division
until the time when that cell itself divides.
• Arise – Divide
• This consist of periods of;
•Growth and Development
•DNA Replication
•Preparation For Division
•Cell Division
• Cell after division begins a new cycle
The Cell Cycle
• Consist of two(2) main
periods;
I. Interphase
II. Mitotic Phase M phase
G2
phase
S
phase
G1 phase
CELL CYCLE - Interphase
• Interphase: period of growth and DNA
replication between cell divisions
• Three (3) phases:
• G1 Phase
‒ Cell increases in size
• S Phase
‒ Replication of DNA
‒ Two sister strands of DNA called chromatids
are produced
• G2 Phase
‒ Organelles double
‒ New cytoplasm forms
‒ All other structures needed for mitosis form
Centrioles
Nuclear membrane
Nucleolus
Chromosomes
M phase
G2 phase
S phase
G1 phase
CELL CYCLE
CELL CYCLE – Mitotic Phase
• Mitotic phase is the stage when a cell divides
• Mitosis – the division of a single nucleus into two genetically
identical daughter nuclei
• This division involves two(2) processes;
‒ Division of the nucleus
‒ Separation of the cytoplasm and the new nuclei into daughter cells
Mitotic Phase
• Divided into two (2) mitotic phases
• 1st MP contain four stages (P-MAT)
‒ Prophase, metaphase, anaphase and telophase
• 2nd MP is cytokinesis
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
•P-MAT
Interphase 1 2
3
4
Cytokinesis
Mitosis
Interphase:
Centrioles
Nuclear membrane
Nucleolus
Chromatids
Early Prophase:
• Chromatids condense becoming
chromosomes
• Nucleolus disappears
• Centrioles separate and start moving
to opposite ends of the cell
• Spindle begins to form
Chromatids
connected by a
centromere.
Centrioles
Spindle made of
microtubules
Late Prophase:
• The nuclear membrane
fragments and the
microtubules invade the
nuclear area
• Centrioles have moved to the
opposite poles
• The spindle is completely
formed
centrioles
Microtubules
form a complete
spindle
chromatids
centrioles
Metaphase:
In metaphase;
• The chromosomes are aligned
at the metaphase plate
• Centrioles move at polar ends
and projects spindle fibers to
connect each chromosome
Centrioles
Chromosomes
Spindle
composed of
microtubules
Anaphase:
In anaphase;
• The paired chromosomes
(sister chromatids) separate
• Separated chromatids move
to opposite pole
• Partial division of cytoplasm
begins
Chromatids are
being pulled to
opposite sides of
the cell.
Shortening of the
microtubules
Telophase:
In telophase;
• Chromosomes are at the
poles
• Chromosomes uncoil-turn
chromatin
• Nuclear envelops reforms
• Spindle fiber disappear
Nuclear
membrane
is returning
Cells return to interphase
Cytokinesis:
• Occurs at the end of mitosis
• Animal cells: a cleavage furrow
separates the daughter cells
• Plant cell: a cell plate separates the
daughter cells
• Daughter cells are genetically
identical
Mitosis
Animation
1. Name the phases
starting at the top.
Mitosis
SELF QUIZ
Design an Education Game from Here
A
B
C
D
E
Name the phases:
1. Identify W
Sister Chromatid
2. Identify X
Spindle fibre
3. Identify Y
Centriole
4. Identify Z
Centromere
SELF QUIZ
z
w
Name this phase
and provide brief
description
Telophase
CONTROL OF THE CELL CYCLE
• Regulatory proteins called cyclins control the cell cycle at
checkpoints:
• G1 Checkpoint—decides whether or not cell will divide
• S Checkpoint—determines if DNA has been properly replicated
• Mitotic Spindle Checkpoint—ensures chromosomes are aligned at
mitotic plate
REFERENCE
• Nabor, Murray W., INTRODUCTION TO BOTANY. Copyright 2004 Pearson
Education, Inc., Publilshing as Benjamin Cummings, 1301 Sansome St., San
Francisco, CA 94111.
www.aw-bc.com
• CK – 12
https://www.ck12.org/biology/cell-division/lesson/Cell-Division-BIO/
• Image Attributions
[Prokaryotic cell division]
Credit: Mariana Ruiz Villarreal (LadyofHats) for CK-12 Foundation
Source: CK-12 Foundation
License: CC BY-NC 3.0

2-190118112234.pdf

  • 1.
    THE CELL CYCLEAND CELL DIVISION Presented by: Fasama Hilton Kollie Lecturer, Department of Biology Mother Patern College of Health Sciences
  • 2.
    CHAPTER OUTLINE 1. CellDivision 2. Importance of Cell Division 3. Prokaryotic and Eukaryotic Cell Division 4. Cell Cycle 5. Regulation of the Cell Cycle
  • 3.
    LESSON OBJECTIVES • Bythe end of this session, the learners will be able to; 1. Define cell division and cell cycle 2. Identify the purpose of cell division 3. Describe cell division in prokaryotic and Eukaryotic cell 4. Describe the cell cycle
  • 4.
    CELL DIVISION • It’sthe process by which a cell divides to form two new cells • Three types of cell division or cell reproduction in organism • Prokaryotes (bacteria) — Binary fission • Divides forming two new identical cells
  • 5.
     Eukaryotes — Mitosis •Cell or organism growth • Replacement or repair of damaged cells — Meiosis • formation of sex cells, or gametes
  • 6.
    WHY DO CELLSDIVIDE? • Cells divide for growth, development, repair of worn-out tissues and reproduction • To facilitate the exchange of materials • To control DNA overloading
  • 7.
    PROKARYOTIC CELL DIVISION 1.Binary Fission • Three (3) major steps; • DNA Replication DNA is copied resulting into two identical chromosomes • Chromosome Segregation Chromosomes separate and move towards ends (poles) of cell • Cytokinesis (Separation) Cytoplasm divides forming two (2) cells • Each new daughter cell is Genetically Identical to parent cell
  • 8.
  • 9.
    EUKARYOTIC CELL DIVISION •Cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent cell 1. MITOSIS • Two (2) main steps: 1. Mitosis Fours steps; [Prophase>Metaphase>Anaphase>Telophase] 2. Cytokinesis Cytoplasm divides forming two new daughter cells • Each daughter cell is Genetically Identical to parent cell
  • 11.
    Eukaryotic Cell DivisionCont. • Cell division that results in four daughter cells 2. MEIOSIS • Two (2) major steps: 1. Mitosis Fours steps; [Prophase>Metaphase>Anaphase>Telophase] 2. Cytokinesis Cytoplasm divides forming two new daughter cells • Each daughter cell is NOT Genetically Identical to parent cell
  • 12.
  • 13.
    THE CELL CYCLE •The sequence of events from the time a cell first arises as a result of cell division until the time when that cell itself divides. • Arise – Divide • This consist of periods of; •Growth and Development •DNA Replication •Preparation For Division •Cell Division • Cell after division begins a new cycle
  • 14.
    The Cell Cycle •Consist of two(2) main periods; I. Interphase II. Mitotic Phase M phase G2 phase S phase G1 phase
  • 15.
    CELL CYCLE -Interphase • Interphase: period of growth and DNA replication between cell divisions • Three (3) phases: • G1 Phase ‒ Cell increases in size • S Phase ‒ Replication of DNA ‒ Two sister strands of DNA called chromatids are produced • G2 Phase ‒ Organelles double ‒ New cytoplasm forms ‒ All other structures needed for mitosis form Centrioles Nuclear membrane Nucleolus Chromosomes
  • 17.
    M phase G2 phase Sphase G1 phase CELL CYCLE
  • 18.
    CELL CYCLE –Mitotic Phase • Mitotic phase is the stage when a cell divides • Mitosis – the division of a single nucleus into two genetically identical daughter nuclei • This division involves two(2) processes; ‒ Division of the nucleus ‒ Separation of the cytoplasm and the new nuclei into daughter cells
  • 19.
    Mitotic Phase • Dividedinto two (2) mitotic phases • 1st MP contain four stages (P-MAT) ‒ Prophase, metaphase, anaphase and telophase • 2nd MP is cytokinesis
  • 20.
    1. Prophase 2. Metaphase 3.Anaphase 4. Telophase •P-MAT Interphase 1 2 3 4 Cytokinesis Mitosis
  • 21.
  • 22.
    Early Prophase: • Chromatidscondense becoming chromosomes • Nucleolus disappears • Centrioles separate and start moving to opposite ends of the cell • Spindle begins to form Chromatids connected by a centromere. Centrioles Spindle made of microtubules
  • 23.
    Late Prophase: • Thenuclear membrane fragments and the microtubules invade the nuclear area • Centrioles have moved to the opposite poles • The spindle is completely formed centrioles Microtubules form a complete spindle chromatids centrioles
  • 24.
    Metaphase: In metaphase; • Thechromosomes are aligned at the metaphase plate • Centrioles move at polar ends and projects spindle fibers to connect each chromosome Centrioles Chromosomes Spindle composed of microtubules
  • 25.
    Anaphase: In anaphase; • Thepaired chromosomes (sister chromatids) separate • Separated chromatids move to opposite pole • Partial division of cytoplasm begins Chromatids are being pulled to opposite sides of the cell. Shortening of the microtubules
  • 26.
    Telophase: In telophase; • Chromosomesare at the poles • Chromosomes uncoil-turn chromatin • Nuclear envelops reforms • Spindle fiber disappear Nuclear membrane is returning
  • 27.
    Cells return tointerphase Cytokinesis: • Occurs at the end of mitosis • Animal cells: a cleavage furrow separates the daughter cells • Plant cell: a cell plate separates the daughter cells • Daughter cells are genetically identical
  • 28.
  • 29.
    1. Name thephases starting at the top. Mitosis SELF QUIZ Design an Education Game from Here A B C D E
  • 30.
    Name the phases: 1.Identify W Sister Chromatid 2. Identify X Spindle fibre 3. Identify Y Centriole 4. Identify Z Centromere SELF QUIZ z w
  • 31.
    Name this phase andprovide brief description Telophase
  • 32.
    CONTROL OF THECELL CYCLE • Regulatory proteins called cyclins control the cell cycle at checkpoints: • G1 Checkpoint—decides whether or not cell will divide • S Checkpoint—determines if DNA has been properly replicated • Mitotic Spindle Checkpoint—ensures chromosomes are aligned at mitotic plate
  • 33.
    REFERENCE • Nabor, MurrayW., INTRODUCTION TO BOTANY. Copyright 2004 Pearson Education, Inc., Publilshing as Benjamin Cummings, 1301 Sansome St., San Francisco, CA 94111. www.aw-bc.com • CK – 12 https://www.ck12.org/biology/cell-division/lesson/Cell-Division-BIO/ • Image Attributions [Prokaryotic cell division] Credit: Mariana Ruiz Villarreal (LadyofHats) for CK-12 Foundation Source: CK-12 Foundation License: CC BY-NC 3.0