Transcript Cell Reproduction

Cell Reproduction
 Chromosomes
 Cell Division
Chromosomes
• Chromatin Structure
• Chromosome Structure
• Chromosome Condensation
• Sister Chromatids
Learning
Objectives
• TSW …
1. Distinguish between chromatin
& condensed chromosomes
2. Describe the location &
structure of a chromosome
3. Describe chromosome
condensation
4. Explain what sister chromatids
are
Chromosomes
• Chromosome Structure
 DNA – deoxyribonucleic acid
 Proteins
When NOT involved in
Histones
cell
• Serve
asdivision,
“spools” for long DNA molecule
chromosomes
exist
as
• Maintain
chromosome
shape
chromatin – a mixture
Nonhistone
proteins
of DNA & proteins w/in
• Control
the regional
nucleus activity of DNA
• Chromosome Function
 Genetic Code – hereditary material
Chromosome
Condensation
histones
 coiling around histones
 coiling into supercoils
 further coiling into visible
structures (light microscope)
Chromosome & Sister
Chromatids
•
Terminology:
 centromere
constricted region of chromosome
sister chromatids are joined here
 kinetochore – structure w/in
centromere where spindle microtubules
attach to sister chromatids
 1 kinetochore for each chromatid
Roles of Cell Division
• Asexual Reproduction
 prokaryotes
 protistans
 fungi
 plants
 primitive animals
• Growth & Development
 multicellular organisms
• Repair & Regeneration
 multicellular organisms
Growth & Development
Fertilized egg
Multicellular
Organisms
Ist division
Early embryo
Late embryo
Fetus
Toddler
Young child
Young adult
Tissue Renewal
Multicellular
bone marrow
Organisms
stem cells
Tissue Repair
The Cell Cycle Movie
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 1 min
Cell Division
• The Cell Cycle
 Interphase
 Mitosis
 Cytokinesis
Learning
Objectives
• TSW …
1. Describe each phase of the cell
cycle
2. Summarize the phases of
mitosis
3. Compare cytokinesis in plant &
animal cells
Cytoskeletal Elements
of Division
• Terminology:
 centrosome
microtubule organizing center (MTOC)
synthesizes mitotic spindle
 centrioles
animal cells only
2/centrosome
9 sets of triplet microtubules arranged
in ring
Mitotic Cell Cycle:
“mitotic phase” =
Overview
division
of the
cell:
•mitosis
Major Stages of Mitotic Cell
Division:
cytokinesis
 Interphase
Divided into 3 phases
 Mitosis (M phase)
Divided into 4 main phases
Phases often subdivided
 Cytokinesis (M phase)
Animal cell process
Plant cell process
Interphase:
Phases of Interphase
• Preparatory Stage:
 G1 phase
cell growth; organelles duplicate;
mitochondria & chloroplasts selfreplicate
 S phase
DNA replication
 G2 phase
enzymes & other materials necessary
for division synthesized; cell growth
continues
DNA Replication
Interphase
Interphase
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 25 sec
Phases of Mitosis
• Prophase
A
• Prometaphase
• Metaphase
Pneumonic
• Anaphase
• Telophase
Aide!
Proud
Pittsburgh
Made
A
Touchdown
Mitosis: Prophase
• Division of the Nucleus:
 Early Prophase
chromosomes condense as sister
chromatids
nucleoli disperse
spindle apparatus begins to form from
centrosomes (MTOC)
Chromosome & Sister
Chromatids
Mitosis:
Early Prophase
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 20 sec
Mitosis: Late Prophase
• Division of the Nucleus:
 Late Prophase (Prometaphase)
nuclear envelope fragments
mitotic spindle stretches across cell
spindle microtubules:
• Kinetochore tubules – some attach to
chromosomes at kinetochores
• Polar fibers – other microtubules stretch
toward poles
Mitosis:
Late Prophase
(Prometaphase)
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 20 sec
Mitosis: Metaphase
• Division of the Nucleus:
(cont)
 Metaphase
spindle across cell w/ centrosomes at
opposite poles
chromosomes line up across
metaphase plate [cell equator] with
sister chromatids on opposite sides of
equator
• “kinetochore tubules” attached to sister
chromatids
• “polar” microtubules span cell from
equator to each pole
Spindle Apparatus
Centrosomes
centrosome
Kinetochore Structure
Mitosis:
Metaphase
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 12 sec
Mitosis: Anaphase
• Division of the Nucleus:
(cont)
 Anaphase
centromeres separate
sister chromatids move to opposite
cell poles as kinetochore tubules
shorten
Polar tubules lengthen to stretch cell
Kinetochore Function
Mitosis:
Anaphase
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 22 sec
Mitosis: Telophase
• Division of the Nucleus:
(cont)
 (Early) Telophase
polar fibers lengthen stretching cell
chromosomes (formerly sister
chromatids) reach opposite poles of
cell
Mitosis: Telophase
• Division of the Nucleus:
(cont)
 (Late) Telophase
daughter nuclear envelopes reform
daughter nucleoli reform
chromosomes decondense to
chromatin
Mitosis:
Telophase
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 20 sec
Cytokinesis
• Division of the Cytoplasm:
 Begins during early telophase
 Finishes immediately after
telophase
 Daughter cells separated by
different mechanisms in plants &
animals
Cytokinesis
Cytokinesis
• Cleavage furrow formation:
animal cells
microfilaments attached to cell
membrane shorten
Cell is pinched in two
Daughter nuclei separated
Results in 2 daughter cells with identical
genetic material
Cytokinesis
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 41 sec
Mitotic Cell Division:
Time Lapse
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• ASF Video plays about 52 sec
Review of Mitosis &
Cytokinesis
• To View Video:
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– When hand appears, click once
• MOV Video plays about 30 sec
Mitosis Review
Mitosis Review
Regulation of Mitosis
Cancer
Cells & Human Biology
• To View Video:
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– When hand appears, click once
• ASX Video plays about 16 min
Compound Light
Microscope
Arm
Base