 Opener: Why do cells
divide?
 Agenda
 Intro Unit 7
 Why do cells divide?
 Mitosis slide lab
 Mitosis stages
 Homework
none
 Growth
 Organisms grow by increasing number of cells
 Repair/ Renewal
 Cell division occurs to repair damaged tissues
 Asexual Reproduction
 Some single-celled organisms reproduce by dividing
•Cell before divisionDNA replication
occurs
•DNA condenses
into visible
chromosomes
•Chromosomes line
up at center of the
cell
•Spindle fibers pull
chromosomes apart
•New nuclei form
Onion Root Tip Cell Division
Find and draw cells that you think are doing the
following steps of cell division.
The chromosomes are not coiled up and are therefore
difficult to see
Chromosomes coil up so they can be seen
Chromosomes line up at the center of the cell
Spindle fibers pull chromosomes apart
Two nuclei form and the cell splits
 Opener:
How does an entire
organism arise from
1 cell (zygote)?
 Agenda
Mitosis cont.
Mitosis vs.
Meiosis
 Homework
1.
Interphase
2.
Prophase
3.
Metaphase
4.
Anaphase
5.
Telophase
6.
Cytokinesis
 http://www.slideshare.net/anason
ea/mitosis-flip-book
http://media.pearsoncmg.com/bc/bc_0media_bio/bioflix/bioflix.htm?8apmi
tosis
Contrast Meiosis and Mitosis
Meiosis
# of parent cells?
# of daughter cells?
haploid or diploid
daughter cells?
Genetically identical or
different daughter cells?
Type of cell produced?
# of cellular divisions?
Purpose/Importance?
Mitosis
Meiosis
Mitosis
# of parent cells?
1
1
# of daughter cells?
4
2
haploid
diploid
Genetically identical or
different daughter cells?
different
identical
Type of cell produced?
Gametes
(sex cells)
Somatic
(body cells)
# of cellular divisions?
2
1
Purpose/Importance?
Gamete
production in
sexual
reproduction
Growth,
repair/renewal,
asexual
reproduction
haploid or diploid
daughter cells?
 Opener:
Do you think there are
really cells that look like
this?
 Agenda
Differentiation
Cell Survey Lab
 Homework
 Specialization in the structure and
function of a cell
 Occurs during development of an
organism
 Results from the activation and
deactivation of certain genes in the cell
 Draw a picture of your cells.
 What type of cells are you looking
at?
 Give a justification of your guess
by linking the cell’s structure to
its function.
 Example:
 “I think this is a neuron
because it has a lot of fibers
that can connect to other cells
for communication.”
Cell Types
 Bone
 Skin
 Retina (eye)
 Blood
 Muscle
1.
Observe the tissue at your station
2.
As a group, come to a conclusion as to what tissue you are
observing.
3.
Create a sketch of what you see in the correct location in your
table (detailed and neat).
4.
Describe the structure of the tissue in words.
5.
Explain the connection between the tissue structure and tissue
function.
Tissues
 Small Intestines Muscle Blood-
Absorb nutrients from food
Bone- Provide support for the body
Relax and contract to allow for movement
Skin-
Move oxygen and nutrients through the body
Lung-
Provide protection from
the environment
Absorb oxygen into the
body and release carbon dioxide
 Opener
 What’s so special
about stem cells?
 Agenda
Stem Cells
 Homework
Meet in
computer lab
tomorrow
Stem Cells-undifferentiated cells
 Totipotent- can
give rise to an
entire new
organism
 Pluripotent- can
give rise to any
type of tissue, but
not a new
organism
http://learn.genetics.utah.edu/content/tec
h/stemcells/scintro/
In a stem cell, the DNA is arranged loosely, with its
genes ready to spring into action.
As signals enter the cell and differentiation begins,
genes that will not be needed are shut down, and
genes that will be required for a specialized
function remain open and active.
http://learn.genetics.utah.edu/content/tech/cloning/clickandclone/
 Until recently, once a cell became specialized, it
was referred to as "terminally differentiated.”
 In 2007, researchers were able to turn a
differentiated cell back into a stem cell with the
potential to become any type of cell in the body.
Stem Cells:
The Promise vs. The Controversy
 http://www.youtube.com/w
atch?v=2VTA1tXXyTc
 http://www.pbs.org/wgbh/
nova/body/stem-cellsbreakthrough.html
 Skin Gun:
https://www.youtube.com/
watch?v=eXO_ApjKPaI
 http://www.ted.com/talks/susan_solomon_the_promise_of_r
esearch_with_stem_cells/citations
 http://www.youtube.com/watch?v=2VTA1tXXyTc
 Stem Cells Lab day
 Opener
 Can you think of an
example of how cells
communicate in your
body?
 Agenda
 Calendar
 Back to business
questions
 Cell
Communication
 Cell signaling
 Homework
 Cells communicate with each other using chemical signals.
 In order for a cell to receive a message, it must have the
proper receptor. (Think about a radio)
 Cells can communicate in a number of ways:
 Local-specific
ex. Neuron
 Local-broadcast
 Long distance
ex. Growth factor
ex. insulin production, fever response
1. Reception
 A signal binds to a receptor on the receiving cell
2. Transduction
 The receptor binding causes a change (sometimes a
series of changes) on the inside of the cell.
3. Response
 This will result some sort of response by the
receiving cell. Passing on a signal, releasing a
protein, begin transcription, etc.
Apoptosis
 http://www.youtube.com/watch?v=9KTDz-ZisZ0
Flu
 https://www.youtube.com/watch?v=Rpj0emEGShQ
 Cell communication stations
 Opener:
 What has to happen to a
zygote to become a fully
formed adult?
 Agenda
Embryology
Review cell
signaling &
Embryology
Readings
 Homework
 http://www.youtube.com/watch?v=lXN_sDnd1ng&fe
ature=related
 http://www.youtube.com/watch?v=UgT5rUQ9EmQ&
feature=related
A single cell, formed by the fertilization of an
egg by a sperm, divides to form a morula
(Latin – “mulberry”) – a solid ball of cells
Pg 157
Pg 160
Solid ball of cells
develops into
blastula or
blastocyst- a
fluid filled ball of
cells that will
develop into the
embryo and
placenta
Pg 157
 Gastrulation: (Greek – gastros = “belly”)
primitive gut is formed by infolding of blastula
 Inner cell mass forms
three distinct layers of
cells: ectoderm - “outside
skin”, endoderm - “inside
skin”, and mesoderm “middle skin”
1.Fertilized Egg- Zygote
2.Cell Division (Mitosis)  Solid Ball of Cells
(Morula)
3.Morula  hollow ball of cells (blastula)
4.Gastrulation  Indentation that forms
digestive tract

 Opener:
What’s happening in
this photo?
 Agenda
Intro Dictyostelium
Dictyostelium lab
 Homework
none
http://www.nsf.gov/news/special_reports/fib
r/dictyo.htm
 Students must wash their hands before and after each lab session.
 Lab work areas should be wiped down with 70% ethanol prior to lab
work.
 Equipment (forceps, etc.) should be dipped in 70% ethanol and flamed.
 Petri dishes should be kept closed except for the limited time during
which materials are being added.
 When adding material to the Petri dishes, only open the dish as much
as needed; try to keep the agar as covered as possible.
 When working with the Petri dish lid tilted open, work as quickly as
possible; keep your face back to avoid breathing on the dish and do not
position your hand directly above the dish.
 http://www.youtube.com/watch?v=Ay2hhujTuvg&feature=relmfu
1. Wash your hands
2. Disinfect lab table
3. Label Petri Dish:
Group name – Period