1. Cell Cycle Steps to Mitosis

2. Types of Cells Review
Prokaryotes – No nucleus OR membrane bound organelles
Examples: Bacteria
Eukaryotes – Has a nucleus AND membrane bound organelles
Examples: Plants and animals

3. Prokaryotes Prokaryotes – Lack nucleus Has a single chromosome
Reproduces by binary fission
Includes bacteria

4. What is binary fission? Type of reproduction used by bacteria
Cells increase their cell mass slightly
DNA and cell components are replicated
Each cell divides into 2 daughter cells

5. Eukaryotes Contains a nucleus and membrane bound organelles
Asexually reproduce cells by a process called mitosis

6. 2 Reasons why cells divide
DNA OVERLOAD
1. _____________________ As cell grows bigger demand on DNA “genetic library” becomes too great
Ex: Small town library has 1000 books.
As town grows and more people borrow books, there may be a waiting list to read the most popular titles

7. 2 Reasons why cells divide
Material exchange can’t keep up
2. _____________________ As cell grows bigger demand for transport across membrane is too great

8. More on Why Cells Divide
Ability to transport of oxygen, food, waste across cell membrane depends on _______________
Need for these depends on ___________
SURFACE AREA
CELL VOLUME
As cell grows these DON’T increase at the same rate
Surface-Area to Volume Ratio Animation

9. Ratio of Surface Area to Volume in Cells
Cell Size
Surface Area (length x width x 6)
Volume
(length x width x height)
Ratio of Surface Area to Volume

10. BIGGER CELLS NEED MORE FOOD and OXYGEN, but CAN’T TRANSPORT
IT FAST ENOUGH or IN BIG
ENOUGH QUANTITIES!

11. mainly by increasing cell number
Image from:
Image by Riedell
Multicellular organisms grow
mainly by increasing cell number

12. DNA CAN BE: SPREAD OUT IN NON-DIVIDING CELLS SCRUNCHED UP
IN DIVIDING CELLS
CHROMATIN
CHROMOSOMES

13. DNA in PROKARYOTES BACTERIAL DNA is CIRCULAR HAVE ONE CHROMOSOME
NO NUCLEUS; ATTACHED TO CELL MEMBRANE

14. DNA in EUKARYOTES (Plants & Animals)
DNA is ROD-SHAPED CHROMOSOMES
MANY PAIRS
FOUND IN NUCLEUS

15. Chromosome structure SISTER CHROMATIDS CENTROMERE HOMOLOGOUS
___________________ identical arms
__________________
constricted area holds chromatids together
CENTROMERE
HOMOLOGOUS
__________________ PAIR
2 of each chromosome (one from mom; one from dad)

16. HOMOLOGOUS CHROMOSOMES
SAME SIZE
SAME SHAPE
CARRY GENES for the SAME TRAITS
BUT ______________!
(Don’t have to have the SAME CHOICES)
NOT IDENTICAL

17. CELL DIVISION in PROKARYOTES
Bacteria reproduce using
__________________________________
BINARY FISSION

18. Cell Cycle
__________= series of events that cells go through as they grow and develop

19. Cell Cycle Stages in growth & division G1 Phase (Gap 1)
S Phase (Synthesis)
G2 Phase (Gap 2)
M Phase (Mitosis)
Cytokinesis

20. CELL CYCLE INTERPHASE – non-dividing phase
G1- Grow bigger Cell is “doing its job” DNA is spread out as chromatin
S - Synthesis (copy DNA) & chromosomal proteins
G2- Grow bigger, make organelles & molecules needed for cell division

21. CELL DIVISION MITOSIS – Nuclear division Prophase Metaphase Anaphase
Telophase
Cytokinesis – Cytoplasm divides
G0 – cell stops dividing (Ex: nerve cell)

23. Mitosis has no beginning and no end
Life Cycle of A Cell
Mitosis has no beginning and no end

24. Stages of Mitosis Interphase – “Resting Phase”
Cells carrying on normal activities
Chromosomes are not visible
Cell metabolism is occurring
Occurs before mitosis

25. Cells Undergoing Mitosis

26. PROPHASE DNA scrunches into chromosomes
Pearson Education Inc publishing as Pearson Prentice Hall
PROPHASE
1st dividing phase
DNA scrunches into chromosomes
Centrioles appear in centrosome region & move to poles
Nuclear membrane & nucleolus disappear
Spindle fibers form & attach to chromosomes

27. ________ region organizes spindle
CENTROSOME
Spindle MICROTUBULES are part of cytoskeleton

28. METAPHASE middle Chromosomes line up in ___________
Images from: Pearson Eduction Ince; Publishing as Pearson Prentice Hall

29. ANAPHASE Centromeres split Centrioles pull chromatids_______ apart
Images from: Pearson Eduction Ince; Publishing as Pearson Prentice Hall

30. two See ______ nuclei Nuclear membrane & nucleolus return
TELOPHASE (reverse prophase steps)
two
See ______ nuclei
Nuclear membrane & nucleolus return
Chromosomes spread out as chromatin
Centrioles disappear
Spindle fibers disappear
Images from: Pearson Eduction Ince; Publishing as Pearson Prentice Hall

31. CYTOKINESIS Cytoplasm splits into 2 cells CLEAVAGE FURROW
ANIMAL CELLS pinch cytoplasm in two
with a ______________________
CLEAVAGE FURROW

32. CYTOKINESIS Cytoplasm splits into 2 cells
PLANT CELLS can’t pinch because
they have a sturdy ____________
Plant cells separate cytoplasm by growing a _______________ down the middle.
CELL WALL
CELL PLATE

33. Mitosis Fun Mr. Parr's Version - Mitosis Song Mitosis Animation
Mitosis Animation - Via YouTube

34. Concept Map
Cell Cycle
includes
is divided into
is divided into

35. Concept Map Cell Cycle Section 10-2 includes M phase (Mitosis)
Interphase
is divided into
is divided into
G1 phase
S phase
Prophase
G2 phase
Metaphase
Telophase
Anaphase