Today in Biology
Homework: Make
Biology Learning Goal: Overview of sure- review
turned in
chapter 6 – Genes, DNA,
vocabulary
Chromosomes and chromatids
complete
Warm Up Question:
Fact of the Day
Look at definition of binary fission. Does Rats multiply so
this happen in prokaryotes or
quickly that in 18
Eukaryotes? Explain.
months, two rats
could have over 1
To Do Today:
million
1.Make sure review from Q.1 is
descendants.
turned in.
Week #2 Quarter 2 (10/21)
2.Complete vocabulary words for Chap6
3.Make sure notebook Q2 notebook
done
Today in Biology
Week #2 Quarter 2 (10/22)
Biology Learning Goal: Overview of
chapter 6 – Genes, DNA,
Chromosomes and chromatids
Warm Up Question:
What do you know about Mitosis?
Explain.
To Do Today:
1. Check notebook – complete
2. Overview of Chapter 6 Notes
Homework:
None
Fact of the Day
If one was to
weigh all of the
land animals of
the earth, 10%
of that mass
would be ants.
Review of Cells
Over view of cells
 http://wn.com/cells_biology

introduction to cells segment.
human anatomy - the body made entirely of
cells - which make up tissues - which
make up organs - which make up organ
systems - which make up you
41
How do terms differ in
meaning
Cell division and gamete
Cell division process in which new cells form
Gametes=reproductive cells that form by one type of cell
division
Gene and DNA
DNA is a substance made of
nucleotides that stores information
about when and how to make proteins
Gene a segment of DNA that codes for a protein or RNA
molecule
65
Chromosome and
chromatids
Chromosomes=structures
made of DNA and
associated proteins
Chromatids=two parts of a
chromosome that
contain identical copies
of DNA and are joined
by centromere.
draw
TELOMERE
TELOMERE
CELL
REPRODUCTION
How do little elephants grow up to be BIG elephants?
Why do animals shed their
skin?
Three reasons why cells
reproduce by asexual
reproduction (divide):
1. Growth
2. Repair
3. Replacement
Skin cancer - the abnormal growth
of skin cells - most often develops
on skin exposed to the sun.
Cell that reproduce by asexual
reproduction reproduce constantly.
What is Mitosis?
Mitosis
MITOSIS- reproduction of
somatic (body) cells also known
as NUCLEAR DIVISION
TERMS USED………..
Diploid= full # of chromosomes or (2n)
Haploid= half # of chromosomes or (n)
SOMATIC CELLS is any biological cell
forming the body of an organism; that
is, in a multicellular organism, any cell
other than a gamete, germ cell,
gametocyte or undifferentiated stem
cell. (ex. skin, nerve, muscle cells)
Today in Biology
Week #2 Quarter 2 (10/23&24)
Biology Learning Goal: Overview of
chapter 6 – Genes, DNA,
Chromosomes and chromatids
Warm Up Question:
Explain the difference between haploid
and diploid cells.
To Do Today:
1. Check notebook – complete
2. Begin discussion on cell cycle
3.Mitosis notes
4.Mitosis flip book
Homework:
None
Fact of the Day
A hedgehog's
heart beats 300
times a minute on
average
Cell
cycle
Cell cycle and reproduction
http://vimeo.com/41301118
Page 7
Cell Cycle
Regular sequence of cell
growth and division
Time it takes varies with
type of cell and external
factors
Phases of cycle
G1
S
G2
Mitosis
 Cell increases in size
 New organelles made
 DNA replication (copying)
 Preparation of structures needed for
mitosis & cytokinesis
 Chromosomes begin to coil and
condense (shorten & thicken)
 Division of material in nucleus
Cytokinesis  Division of cytoplasm and organelles
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2 animation__mitosis_and_cytokinesis.html
Prophase
Spindle fibers
 Chromatin shortens
centrioles
and thickens
 Nuclear membrane
and nucleolus
disappear
nucleus
 Spindle fibers
appear and attach
 In animals, centrioles
move to poles
chromatid
centromere
Chromosome with
replicated DNA
Metaphase
 Chromosomes line
up single file at
equator
Pole
Spindle
fibers
Equator
Pole
Anaphase
 Chromatids separate
 Chromatids move to opposite poles
 Each chromatid is now called a
chromosome
Pole
Pole

Telophase
Begins when chromosomes reach poles
 Spindle disappears
 Nucleus is re-formed
 Chromosomes diffuse to become chromatin
 Cytokinesis may occur
Cytokinesis
 Division of cytoplasm
 Usually occurs during
telophase
 In animal cells –
cleavage furrow that
constricts cytoplasm
 In plant cells – cell
plate forms between
two cells
 When mitosis ends – two new
cells with same amount of
DNA
Reasons for Mitosis
 Formation of adult from fertilized egg
(development)
 Maintenance or repair
 Growth in multicellular organisms
 Asexual reproduction in one-celled
organisms
Mitosis – Mr. Parr
http://www.youtube.com/watch?v=IlV9hExXZnM&list=UUJjstNDkwk
tHyvUdtcBfb2g&index=114&feature=plcp
Review
In the 17th century, Robert Hooke peered through a
microscope at a slice of cork and discovered that it was
composed of cells. Centuries later, Rudolf Virchow set
forth the cell theory, in which he proposed that the cell
was the basic unit of all living organisms. We now know
that this theory is true; cells make up all living things,
whether they are plants, animals, or microorganisms.
There is only one way to make more cells—by the
division of those that already exis
16
14
Goal of the Cell Cycle:
To produce two genetically identical cells
from one precursor cell.
1.
Copy and pass on its genetic information to the next
generation of cells. This requires the replication of the DNA
in each chromosome
2. Accurate separation of the chromosomes into the daughter cells
so that each cell receives a copy of the entire genome.
3.Once accomplished, the cell will physically divide to produce
two identical daughter cells
17
15
The entire cell cycle will take different amounts of time
depending of the organism. For example, cell division in the
bacteria (e.g. Escherichia coli) can take as little as 20
minutes. In a single-celled yeast it takes 90-120 minutes .
Cells in organs such as the heart do not divide in the adult,
except in cases where disease or trauma causes damage.
Cells in the nervous system and the brain do not divide after
birth, which is why an injury to the spine is usually
irreversible.
Hair, skin, fingernails, taste buds, and the stomach's
protective lining are replaced constantly and at a rapid rate
throughout our lives reproduce every 15-30 days
18
16
Interphase: This part if the cells life cycle occupies most
of the cells "life". The mitosis portion of the cycle may last
only 10 - 20 hours while some cell can live for days or
weeks.
Mitosis Notes
19
http://www.youtube.com/watch?v=lf9rcqifx34&feature=related
Parts of Interphase:
G1phase: This part of the cell cycle is where the cell spends
most of its life. This is the time when the cells are performing
their assigned tasks. At some point in the cycle something
triggers the cell to begin a cell
division event.
There are many
stimuli which can
cause the cell to require
a cell division:
- To replace dead
or dying cells,
- To produce more
cells
(growth and development)
- Reproduction,
i.e. to increase the
20
number of unicellular organisms.
S-phase: This is known as the synthesis phase. Here
.
the DNA molecules are copied or replicated, therefore
we go from single stranded DNA in G1 phase to
double stranded DNA in G2.
21
G2 Phase
The cell is preparing for the actual division events
For example tubulin the protein of which
microtubules are created is synthesized. This
tubulin will be used to manufacture the
microtubules of the spindle apparatus (fibers) in
prophase of mitosis.
G2 completes
interphase now the
cell is prepared for
mitosis
22
http://www.cellsalive.com/cell_cycle.htm
Animated Mitosis Cycle
http://www.cellsalive.com/mitosis.htm
• Interphase
• Prophase
• Metaphase
• Anaphase
• Telophase & Cytokinesis
Flip Book
Interphase
occurs before mitosis begins
•
Chromosomes are copied (# doubles)
•
Chromosomes appear as threadlike coils (chromatin) at the start,
but each chromosome and its copy(sister chromosome) change to
sister chromatids at end of this phase
Nucleus
CELL
MEMBRANE
Cytoplasm
Interphase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Prophase
1st step in Mitosis
•
Mitosis begins (cell begins to divide)
•
Centrioles (or poles) appear and begin to move to opposite end of
the cell.
•
Spindle fibers form between the poles.
Centrioles
Sister chromatids
Spindle fibers
Prophase
Animal Cell
Plant Cell
Spindle fibers
Centrioles
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Metaphase
2nd step in Mitosis
•
Chromatids (or pairs of chromosomes) attach to the spindle fibers.
Centrioles
Spindle fibers
Metaphase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Anaphase
3rd step in Mitosis
•
Chromatids (or pairs of chromosomes) separate and begin to move
to opposite ends of the cell.
Centrioles
Spindle fibers
Anaphase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Telophase
4th step in Mitosis
•
Two new nuclei form.
•
Chromosomes appear as chromatin (threads rather than rods).
•
Mitosis ends.
Nuclei
Chromatin
Nuclei
Telophase
Animal Cell
Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Cytokinesis
occurs after mitosis
•
Cell membrane moves inward to create two daughter cells – each
with its own nucleus with identical chromosomes.
Animal Mitosis -- Review
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
Plant Mitosis -- Review
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
The only difference…
Both plant and animal cells go through
mitosis, BUT during TELOPHASE plant cells
have a cell plate and animal cells have a
cleavage furrow.
Today in Biology
Homework:
Biology Learning Goal: Overview of Mitosis
Worksheet Due
chapter 6 – Genes, DNA,
Monday
Chromosomes and chromatids
QUIZ MONDAY
Warm Up Question: Reflection turn in! Fact of the Day
When you die
What are spindle fibers?
your hair still
What is a centriole?
grows for a
What is a centromere?
couple of months.
That is why
To Do Today:
ghosts and scary
1.Mitosis flip book
creatures have
2.Mitosis worksheet – homework due
long hair.
Monday
Week #2 Quarter 2 (10/23&24)
Cell Cycle
Mitosis
Flip
Book
19
Overview of Mitosis