1. 121R
Unit V Cell Division
Chp 12 & 13

2. 122L
Cell Cycle: life of a cell from its formation until it divides to make ______ cells.
Functions of Cell Division:
___________- make a new organism.
Growth - increase in___________
Tissue Repair –___________new cells
The Cell Cycle:
Making an ___________copy
Occurs in ___________cells (Body cells)
Happens in plant & animal cells
Results in ___ identical daughter cells
Centrioles
Chromatin

3. Homologous Chromosomes
Genome = all of a cell’s ___________info (DNA)
Prokaryote: single, ___________chromosome
Eukaryote: more than one ___________chromosomes
Ex. Human: ____ chromosomes
123R
Discovery of chromosomes  All Eukaryotic organisms have a ___________ number of chromosomes in their cells Human somatic cells (Body cells) have 46 chromosomes. A ___________chromosome number. After cell division, the ___________cells will contain the ___________number of chromosomes during mitosis. Human ___________cells (sperm & egg) have ____ chromosomes. A ___________ (half) chromosomes number during meiosis. Parts to a chromosome  Chromosomes are always in___________ They are called ___________chromosomes Each chromosome contain the following” * 2 ___________chromatids *1___________ * 2___________
Centromere
Sister chromatids
(Mom)
(Dad)
Homologous Chromosomes

4. Phases of the Cell Cycle
Interphase (90% of cell cycle)
G1S G2
M Phases (___________)
Mitosis: nucleus divides
Cytokinesis:
___________divides
124L
Paste “cell cycle” here
A) Interphase
The majority of a cells life (____) is spent in this growth period.
Divided into three parts: G1, S, G2
G1 = Gap 1
S = Synthesis
G2 = Gap 2
First growth phase
________& development
Metabolic activity
Approx ___ hours
________ synthesis
Chromosome_________
Approx ___ hours
Second growth phase
Synthesis of ___________and replication of centrioles
Approx ___ hours

5. Paste “ Mitosis” picture here
B) Mitotic Phase
Division of the___________
Divided into stages
Prophase
___________
Metaphase
Anaphase
Telophase
125R
Paste “ Mitosis” picture here

6. MITOSIS Prophase Prometaphase 126L Metaphase Nuclear Division
Spindle fibers
Doubled chromosome
Chromosome___________
Mitotic spindle begins to form
Nuclear membrane___________
Disappearing nuclear envelope
Prometaphase
___________membrane begins to disappear
Centromeres contain protein called___________
Mitotic spindle attaches to___________
___________move to opposite sides of cell
Spindle fibers
Metaphase
Centromere
Chromosomes are pulled toward the _______ (Metaphase plate) and line up at the ___________of the spindle.
Spindle fibers

7. Paste “ Cytokinesis” here
Anaphase
127R
Chromosomes move toward ___________ poles
Spindle fibers pull chromosomes to opposite sides of cell
Cell___________
Spindle fibers
Telophase
Nuclear membrane ___________ (reappear)
Chromosomes ___________to form chromatin (threadlike bundles of DNA)
Nuclear envelope reappears
Two daughter cells are formed
C) Cytokinesis
Division of the___________
Animal Cells: cleavage_ __________
Plant Cells: cell _____ forms
Paste “ Cytokinesis” here

8. 128L
Paste “ Drawing of mitosis” here

9. Paste “ Circle of mitosis” here

10. Paste “ concept covered: Name that stage” here
130L
Paste “ concept covered: Name that stage” here

11. Cell Cycle Control System
____________= control point where stop/go signals regulate the cell cycle
G1 checkpoint (Most important!)
Controlled by cell____ , growth factors, ____________
“Go”  completes whole cell cycle
“Stop”  cell enters non-dividing state (G0 Phase)
Nerve, muscle cells, liver cells stay at G0 for an extended period of time. Regrow at a very slow rate
Paste “checkpoints” picture here
Density dependent inhibition
Density dependent inhibition – when normal crowded cells ______dividing
____________dependency – when normal cells are attached to a tissue to divide
Paste “inhibition” picture here

12. Tumors = mass of abnormal cells
Transformation: process that converts a normal cell to a ____________ cell
132L
Cancer cells:
in which cells _______ the ability to control growth by ______ responding to checkpoints.
They ______ the density dependent inhibition and _______ to divide non-stop
Tumors = mass of abnormal cells
______ tumor: lump of cells remain at original site
______ tumor: invasive - impairs functions (called cancer)
_________ : cells separate from tumor and ______ to other parts of body
Bacterial cells
-divide by ________ Fission -____________ simply divide into two cells -occurs very____________
Paste “ binary fission” picture here

13. Types of reproduction:
MEIOSIS
Formation of Gametes
(Egg and sperm)
133R
________ are segments of DNA that code for the basic unit of heredity and transmitted from one generation to the next
_________ are sex cells (sperm & Egg)
A ______ (loci) is the location of a gene on a chromosome.
Types of reproduction:
Asexual reproduction – a _______ parent is the sole parent of passes copies of all its genes to the offspring. Occurs by mitosis. This process gives rises to clones, a group of genetically identical individuals
Sexual reproduction – two individuals (parents) contribute ________ to the offspring. Has a greater genetic________.
Gametes (Meiosis)
Sex cells (sperm/egg)
________ (n): 1 of each type of chromosome
Divide by________
Humans: n = 23

14. Meiosis stages: 134L Facts About Meiosis Interphase
Two meiotic divisions
Meiosis I – separates _________ chromosomes
Meiosis II – separates sister_________
Facts About Meiosis
Produces ___________ (eggs & sperm)
Occurs in the testes in males (____________)
Occurs in the ovaries in females (____________)
Original cell is ____________ (2n)
(Specialized cells – germ cells)
Interphase only takes place at the ____________of meiosis I
____________daughters cells are produced that are haploid (n)

15. Meiosis: Two Part Cell Division
Meiosis I
Meiosis II
Interphase
divided into three parts: G1 – Growth & development
S – DNA____________
G2 –____________replicate S G2 G1

16. Meiosis I: Reduction Division
136L
1st stage = Prophase I
Early prophase
____________pair
Crossing _________ occurs.
Late prophase
Chromosomes____________.
____________forms.
Nuclear envelope____________
Tetrads Form in Prophase I
Homologous chromosomes (each with sister chromatids)  
Join to form a____________
Called Synapsis

17. Crossing- Over Crossing-Over only occurs in prophase I 137R
Homologous chromosomes in a tetrad ________ over each other
Pieces of chromosomes or genes are____________
Produces Genetic ____________in the offspring
Crossing- Over
Each chromatid is now ____________from the other for independent assortment

18. 4th stage = Telophase I/Cytokinesis
2nd stage = Metaphase I
138L
Homologous pairs of chromosomes _______along the equator of the cell
3rd stage = Anaphase I
_________ separate and move to opposite poles.
Sister ____________remain attached at their centromeres.
4th stage = Telophase I/Cytokinesis
Nuclear envelopes____________.
Spindle disappears.
Cytokinesis divides cell into__________ .

19. Meiosis II: Reducing Chromosome Number
5th stage = Prophase II
Nuclear envelope____________.
____________forms.
6th stage = Metaphase II
Chromosomes align along ____________of cell.
7th stage = Anaphase II
Sister __________ separate and move to opposite poles.

20. 8th stage = Telophase II/Cytokinesis
Nuclear ____________assembles.
Chromosomes____________.
Spindle disappears.
____________divides cell into two.
Results of Meiosis
____________ (egg & sperm) form
____________haploid cells with one copy of each chromosome
One allele of each____________
Different ____________of alleles for different genes along the chromosome

21. Paste “Drawing of Meiosis” here

22. 142L
Paste “ concepts: comparing mitosis & meiosis” picture here

23. Paste “ Venn diagram” here

24. Chromosomes & Karyotype
144L
Chromosome Number
____________Cells
Body cells
____________ (2n)
Divide by____________
Humans: 2n = 46 chromosomes

25. Karyotype 145R Paste “Human Karyotype” picture here
A ____________of an individual's somatic cells.
Are arranged in a sequence (#1-23)
Always in____________
____________
Total of 46 chromosomes.
Autosomes – non sex chromosomes #
Sex chromosomes – determines the individual’s sex
# 23
XX – ____________
XY – ____________
Determine disorders of an individual
Paste “Human Karyotype” picture here

26. Nondisjunction Disorders
146L
_______ to separate during meiosis
too few or too many____________
Disorders: (____________) See handout
Paste “ chromosomal nondisjunction disorders” picture here

27. Controlling cell division:
Cell needs essential ____________in order to divide “growth factors”
Skin cells divide most____________
_________ & muscle cells DO NOT divide in a mature adult (Go phase)
Growth factors
protein _________ released by body cells that stimulate other cells to divide
density-dependent inhibition
____________cells stop dividing
each cell binds a bit of ____________factor
not enough activator left to trigger division in any one cell
Cancer cells divide excessively and invade other tissues, they ignore the density – dependent inhibitor
____________– the spread of cancer cells beyond the original site.
Tumor – mass of cancer cells
Benign – noncancerous
Remain at the cancer site
Malignant -____________
Move toward other sites

28. The End