Transcript The Cell Cycle & Cell Division

Q2 WK2 D1
The Cell Cycle
&
Cell Division
science-class.net/PowerPoints/Cell%20Division.ppt
What do we already know?
• Prokaryotic VS
Eukaryotic cells
• Humans have
Eukaryotic cells
• All cells have
organelles (parts)
• Each organelle has a
function (job)
Cell Cycle & Cellular Division
learning goal
“I can describe the purpose, phases and
processes of cellular reproduction”! 
The Cell Cycle
http://www.nobel.se/medicine/laureates/2001/press.html
Cell Cycle cut-out
Cell Cycle
• G1- “Growth” phase. A cell grows quickly; largest
part of the cycle. The beginning phase of cell divison.
• S- “Synthesis” phase; cell’s DNA is copied. Each
chromosome consists of 2 chromatids attached at the
centromere
• G2- “Second Growth” phase. Cell prepares for the
nucleus to divide. A cell will spend nearly 90% of its
life in stages G1 – G2!
• M- “Mitosis” phase; nucleus is divided into 2 nuceli.
Each nucleus has same number of chromosomes.
• C- “Cytokinesis” The cytoplasm divides and 2 NEW
CELLS ARE FORMED 
Cell Cycle cut-out
“S” Phase: Chromosome Diagram
http://www.biologycorner.com/bio1/celldivision-chromosomes.html
Catching Some Killer Rays
• Explain why skin cancer might be more
prevalent in California than in Arizona.
• In 2009, it was reported that new melanoma
cases (dangerous form of skin cancer) was identified
nearly 75% higher in men than women.
Explain why some people can survive skin
cancer, while others can’t.
http://www.epa.gov/sunwise/doc/az_facts_web.pdf
Handout- Catching Some Killer Rays (Sci. Ntbk)
Animated Cycle
http://www.cellsalive.com/cell_cycle.htm
Cancer Cells & The Cell Cycle
• Nearly everyone knows of someone who
either has or had cancer.
• Why is it that some doctors are able to “stop”
the cancer while others may not survive it?
• We will explore how cancer moves through
the cell cycle.
Plate Full of Knowledge: Cancer
& the cell cycle
•
http://science.education.nih.gov/supplements/nih1/cancer/activi
ties/activity2_animations.htm
Each person in your group is responsible for
adding “scoops” (answers) to your plate,
based on each video.
You will place your “scoop”, on the proper
section of your plate, creating… a plate full of
knowledge 
-Cancer & the Cell Cycle activity- gradebook
Cancer & The Cell Cycle: Plate Full of KnowledgeQuestions
Video 1
Scoop1: Describe the rate of cells
Scoop 2: Describe how cancer cells grow
Video 2
Scoop 1: Describe the “cell clock”
Video 3
Scoop 1: What are tumor suppressor genes?
Scoop 2:Describe their importance
Video 4
Scoop 1: What are mutations?
Cancer and the Cell Cycle
Class discussion:
Video 1
Scoop1: Describe the rate of cells
Scoop 2: Describe how cancer cells grow
Video 2
Scoop 1: Describe the “cell clock”
Video 3
Scoop 1: What are tumor suppressor genes?
Scoop 2:Describe their importance
Video 4
Scoop 1: What are mutations?
Cancer Growth- Animation (Video)
• http://www.youtube.com/watch?v=WXTsxPPc
TEs
• Stop & Think 
• During the video, we will pause at specific
phases of cancer development, you will be
asked to explain what is happening in that
phase 
Cancer & the Cell Cycle: Modeling
• Lets go outside 
Cancer Growth- Video Summary
• Video will be replayed
• In your notebook, write a summary of how
cancer cells develop and why they are difficult
to stop and what is needed to ensure tumors
do not replicate
Cancer- Active Reading
Q2 WK2 D2
MITOSIS
When is mitosis used?
• Mitosis: reproduction of somatic (body) cells =
cellular division
• Diploid: full # of chromosomes (2n) = 46
• Haploid: half # of chromosomes (n) = 23
– Somatic Cells (body cells) are Diploid
– Gametes (sex cells) are Haploid
Stages of Mitosis
•Prophase
•Metaphase
•Anaphase
•Telophase
Interphase: The cell prepares for division
• What happens…?
– DNA replicates
– Organelles replicate
– Cell increases in size
Interphase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Prophase: The cell prepares for nuclear division
• What happens…?
– DNA condenses into
chromosomes, spindles
form & nuclear envelope
dissolves. The
chromosomes
become visible
Prophase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Metaphase: The cell prepares
chromosomes for division
• What happens…?
– Chromosomes line
up at the center of
the cell
– Spindle fibers attach
from daughter cells
to chromosomes at
the centromere
Metaphase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Anaphase: The chromosomes divide
• What happens…?
– Spindle fibers pull
chromosomes apart
– ½ of each chromosome
(called chromatid)
moves toward opposite
pole
Anaphase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Telophase: The cytoplasm divides
• What happens…?
– DNA spreads out
– 2 nuclei form
– Spindles dissolve
– Cell membrane
pinches in and
forms the 2 new
daughter cells
Telophase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Cytokinesis: Final step in division
• What happens…?
– Cytokinesis occurs
when the cleavage
furrow appears
– Division of the
cytoplasm
– 2 identical daughter
cells form
Chromosome Review
• Chromosomes (x
shaped)
• Chromatid (1/2 of
an X)
• Centromere (holds
chromatids together)
Homologous Pair: 2 chromosomes together are known as
TETRAD
Asters: Small anchors that hold centrioles to side of
cell