Transcript Aim: What is cellular mitosis?

Aim: What is Asexual
Reproduction?
Do Now: On your paper
Notes are in green
What Does “Asexual
Reproduction” Mean?
• “A” means without.
• “Sexual” refers to sex.
• Therefore, Asexual
Reproduction means to
reproduce WITHOUT SEX.
Weird But True . . .
• It seems obvious . . . Sex and babies go
together. But many, many organisms
make babies without sex!
• Some of these organisms reproduce
without sex ALL of the time. Other
organisms can reproduce either way!
• How do you think life would be different if
humans could reproduce asexually? Write
down at least two ideas.
What are these weird, nonsexual
organisms?
• Some of them may be new to you…
What are these weird, nonsexual
organisms?
• But some may be more familiar than you think…
Types of asexual reproduction
1. Binary Fission/Mitosis
2. Budding
3. Vegetative Propagation
4. Spore Formation
5. Regeneration
6. Parthenogenesis
Binary Fission
• THE SAME AS mitosis.
• In other words, cell division.
•
http://video.google.com/videoplay?docid=1569716337466274469&q=binary+fission&total=18&start=0&num=10&s
o=0&type=search&plindex=0
Binary Fission
from
the regents
people
Budding
• A small piece of an organism falls off and
forms a new organism
• If you could do this, your finger could fall
off and become a baby.
• Some organisms that do this: yeast, many
plants, fungi, hydra, coral
Budding from
the regents
people
Vegetative Propagation
• Cuttings of plants will develop roots when
placed in fertile soil
• Forms colonies of clones
Strawberries
do this very
easily!
•
http://video.google.com/videoplay?docid=5302133060487001476&q=vegetative+propagation&total=1&start=0&num=10&so=0&type=sear
ch&plindex=0
Sporulation / Spore Formation
• “Spore” = a reproductive cell that develops
without union with another cell
• Mushrooms reproduce this way.
•
http://video.google.com/videoplay?docid=6421882189540858078&q=spores+fungus&total=76&start=0&num=10&so=0&type=search&plindex=4
Sporulation from
the regents
people
This is magnified
MOLD, not a plant.
Regeneration
If you cut an
organism in half,
both ends will
form a new
organism.
Planaria (free-living
flatworm)  capable of
extreme examples of
regeneration
Sea stars also do this.
Parthenogenesis
• A female animal reproducing without
mating with a male
Sometimes, a species
will ONLY reproduce
through
parthenogenesis, in
which case a species
will be ONLY female.
The asexual, all-female whiptail
species in the center, surrounded
by two species with males.
Aim: What is cellular
mitosis?
Do Now: On your paper
Cell Mitosis
• Mitosis occurs all over the body (except
for the gonads.)
• Used for GROWTH and REPAIR.
• Occurs in STAGES.
Before we begin . . .
• Let’s imagine that you are moving
apartments . . . What makes more sense?
Taking your stuff to your
new apartment one
thing at a time
Packing your stuff in
boxes before you move it.
Before we begin . . .
• Your cell is faced with the same dilemma.
If you stretched it all out, YOU HAVE
OVER SIX FEET OF DNA IN EACH
CELL. You need to get this WHOLE
message into each new cell every single
time.
• To do this, your cell packs the message
into “boxes” … Known as “chromosomes.”
What is a chromosome?
• A chromosome is a bunch of DNA all
twisted up.
• DNA does this in order to get ready for
cell division. (Just like how you pack
all of your stuff into boxes when you
move from one apartment to another!)
A Chromosome
A Chromosome
A Chromosome
Mitosis Vocabulary
• Mitosis - process by which cells
reproduce Also called Cell division or
binary fission.
• Chromatid - one strand of DNA; after
replication, a chromosome is made up of
two identical chromatids
• Daughter cells - new cells produced by
cell division
How can we remember the stages
of mitosis?
• Interphase
• Prophase
• Metaphase
• Anaphase
• Telophase
I Play Mario All the Time.
Stage One: Interphase
• Cell is NOT reproducing
• Growing and doing its normal job.
• During the end of interphase, DNA makes
a copy of itself
or replicates.
Stage Two: Prophase
• Cell’s DNA condenses and forms visible
chromosomes.
Stage Three: Metaphase
• Chromosomes MEET IN THE MIDDLE
Stage Four: Anaphase
• Chromosomes pull APART.
Stage Five: Telophase
• TWO daughter cells form
• Cells finish dividing.
Let’s Watch It!
One More Time!
• Are the two “daughter cells” created
during mitosis identical to one another
or different from each other? Why do
you say so?
Brainpop- Mitosis
• http://www.brainpop.com/science/cellularlif
eandgenetics/mitosis/
Aim: What is cancer, and
how is it related to
mitosis?
Do Now: On your paper
Notes are in hot pink!!
What is cancer?
• Mouth cancer, just one type of many
cancers caused by smoking cigarettes.
What is cancer?
Cancer is
uncontrolled
mitosis.
What is cancer?
• Normal, healthy cells know when to divide
and when not to. Your cells normally
cooperate and do their jobs well, like lawabiding people in a city.
What is cancer?
• Cancer cells are like zombies. They are
your own cells, but they aren’t helping you
anymore!!
What is cancer?
• Cancer cells are selfish! Unlike your
normal cells, they don’t do their jobs.
They divide again and again, pushing the
good cells out of the
way!
What does this look like?
Two types of tumors
• Benign tumors do not spread from their
site of origin, but can squash surrounding
cells
• Malignant tumors spread from the original
site and cause secondary tumors. This is
called metastasis. They interfere with
neighboring cells and can block blood
vessels, the gut, glands, lungs, etc.
• Why is cancer so hard to treat? (HINTDO CANCER CELLS INVADE US FROM
THE OUTSIDE? OR ARE THEY PART
OF US?)
• http://www.pbs.org/wgbh/nova/cancer/gro
w_flash.html
http://outreach.mcb.harvard.edu/animations/
biochem.swf