1. The Cell Cycle & Mitosis
Chapter 5

2. 5.1 – The Cell Cycle Key Concept:
Cells have distinct phases of growth, reproduction, and normal functions.

3. The cell cycle has 4 main stages.
The cell cycle is a regular pattern of growth, DNA replication, and cell division.

4. The main stages of the cell cycle are Gap 1, Synthesis, Gap 2, & Mitosis.
Gap 1 (G1): cell growth and normal functions, copy organelles
Synthesis (S): copies DNA
Gap 2 (G2): additional growth
Mitosis (M): includes division of the cell nucleus (mitosis) and division of the cell cytoplasm (cytokinesis)
Mitosis occurs only if the cell is large enough and the DNA undamaged.

5. 15 1 2 13 7 12 11 10 8 9 3 5 4 14 6

6. Cells divide at different rates.
The rate of cell division varies with the need for that type of cell.
Some cells are unlikely to divide (in Gap 0/G0 of the cell cycle)
Example: neurons

7. Cell size is limited. Volume increases faster than surface area.
Cells need to stay small to allow diffusion and osmosis to work efficiently.

8. Surface area must allow for adequate exchange of materials.
Cell growth is coordinated with division.
Cells that must be large have unique shapes.

9. Stop & Review
________: cell growth and normal functions, copy organelles
Gap One
__________: copies DNA
Synthesis
_________: additional growth
Gap Two
________: includes division of the cell nucleus (mitosis) and division of the cell cytoplasm (cytokinesis)
M phase (mitosis)
Mitosis occurs only if the cell is ______ enough and the _____ undamaged.
Large DNA
The rate of cell division varies with the
Need for that type of cell
Volume increases faster than ___________________.
Surface Area
Cells need to stay ___________ to allow ___________ and __________ to work efficiently.
Small diffusion osmosis
______________________ must allow for adequate exchange of materials.
Cell growth is coordinated with _____________.
Division
Cells that must be large have unique _____________.
shapes

10. 5.2 – Mitosis & Cytokinesis
Key Concept:
Cells divide during mitosis and cytokinesis.

11. Chromosomes condense at the start of mitosis.
DNA wraps around proteins (histones) that condense it.

12. DNA plus proteins is called chromatin.
One half of a duplicated chromosome is a chromatid.
Sister chromatids are held together at the centromere.
Telomeres protect DNA and do not include genes.

13. Mitosis and cytokinesis produce two genetically identical daughter cells.
Box 1: Interphase
Interphase prepares the cell to divide.
During interphase, the DNA is duplicated.

14. Mitosis divides the cell’s nucleus in four phases.
Prophase (Box 2)
Chromosomes condense, spindle fibers form, and the nuclear membrane disappears

15. Mitosis divides the cell’s nucleus in four phases.
Metaphase (Box 3)
Chromosomes line up in the middle of the cell

16. Mitosis divides the cell’s nucleus in four phases.
Anaphase (Box 4)
Sister chromatids are pulled apart to opposite sides of the cell

17. Mitosis divides the cell’s nucleus in four phases.
Telophase (Box 5)
Two nuclei form at opposite ends of the cell, the nuclear membranes reform, and the chromosomes uncoil back into chromatin

18. Cytokinesis differs in animal and plant cells.
Cytoplasm separates
Animal cells: membrane pinches the two new cells apart
Plant cells: a cell plate (new cell wall) separates the two new cells

19. Stop & Review Chromosomes ____________ at the start of mitosis.
Condense
DNA wraps around proteins (____________) that condense it.
Histones
DNA plus proteins is called ______________.
Chromatin
One half of a duplicated chromosome is a _______________.
Chromatid
Sister chromatids are held together at the ________________.
Centromere
_____________ protect DNA and do not include genes.
Telomere

20. Stop & Review (cont)
______________ prepares the cell to divide and is when the DNA is duplicated.
Interphase
_____________ is when chromosomes condense, spindle fibers form, and the nuclear membrane disappears
Prophase
_______________ is when chromosomes line up in the middle of the cell
Metaphase
_____________ is when sister chromatids are pulled apart to opposite sides of the cell
Anaphase
_____________ is when two nuclei form at opposite ends of the cell, the nuclear membranes reform, and the chromosomes uncoil back into chromatin
Telophase
__________ is when the cytoplasm separates
Cytokinesis
___________ cells: membrane pinches the two new cells apart
Animal
___________ cells: a cell plate (new cell wall) separates the two new cells
Plant

21. 5.3 – Regulation of the Cell Cycle
Key Concept:
Cell cycle regulation is necessary for healthy growth.

22. Internal and external factors regulate cell division.
Internal Factors
Include physical and chemical signals
Cell to cell contact: when one cell touches another, they stop growing
Growth factors: chemical signals released by cells that tell other cells to grow
Trigger internal factors, which affect the cell cycle
Kinases and cyclins
Kinases: enzymes in cells, some of which help control the cell cycle – those that do are activated by cyclins
Cyclins: proteins that are made and destroyed during the cell cycle; activate kinases
Both help to advance a cell to different parts of the cell cycle

23. Cell division is uncontrolled in cancer.
Cancer cells form disorganized clumps called tumors.
Benign tumors remain clustered and can be removed.
Malignant tumors metastasize, or break away, and can form more tumors.

24. Apoptosis is programmed cell death.
Some cells need to grow and divide but other cells need to die.
Apoptosis is the process of programmed cell death.
Normal feature in healthy organisms
Caused by a cell’s production of self-destructive enzymes
Occurs during fetal development (responsible for separation of fingers and toes)

25. Cancer cells do not carry out normal cell functions.
Cancer cells come from normal cells with damage to genes involved in cell-cycle regulation.
Carcinogens are substances known to cause cancer (they damage those genes)
Chemicals, tobacco smoke, X-rays, UV rays
Standard cancer treatments typically kill both cancerous and normal, healthy cells.

26. Stop & Review
____________ _____________: Include physical and chemical signals such as cell to cell contact: when one cell touches another, they stop growing and growth factors: chemical signals released by cells that tell other cells to grow
External Factors
___________ ______________: examples are kinases and cyclins. Kinases: enzymes in cells, some of which help control the cell cycle – those that do are activated by cyclins. Cyclins: proteins that are made and destroyed during the cell cycle; activate kinases
Internal Factors
Both help to advance a cell to different parts of the cell ___________.
Cycle
Cancer cells form disorganized clumps called __________________.
Tumors
_________________ tumors remain clustered and can be removed.
Benign
_________________ tumors metastasize, or break away, and can form more tumors.
Malignant
__________________ is the process of programmed cell death.
Apoptosis

27. 5.4 – Asexual Reproduction
Key Concept:
Many organisms reproduce by cell division.

28. Binary fission is similar to mitosis.
Asexual reproduction is the creation of offspring from a single parent.
Binary fission produces two daughter cells genetically identical to the parent cells.
Binary fission occurs in prokaryotes.

29. Environment determines which form of reproduction is most advantageous
Asexual reproduction is an advantage in consistently favorable conditions.
Sexual reproduction is an advantage in changing conditions.

30. Some eukaryotes reproduce by mitosis.
Budding forms a new organism from a small projection growing on the surface of the parent.
Fragmentation is the splitting of the parent into pieces that each grow into a new organism.
Vegetative reproduction forms a new plant from the modification of a stem or underground structure on the parent plant.

31. Stop & Review
_______________ _______________ is the creation of offspring from a single parent.
Asexual Reproduction
___________ _______________ is asexual reproduction in prokaryotes and produces two daughter cells genetically identical to the parent cells.
Binary Fission
Asexual reproduction is an advantage in consistently conditions.
Favorable
Sexual reproduction is an advantage in conditions.
Changing
Asexual Reproduction In Eukaryotic Organisms
_____________ forms a new organism from a small projection growing on the surface of the parent.
Budding
__________________ is the splitting of the parent into pieces that each grow into a new organism.
Fragmentation
____________ _________________ forms a new plant from the modification of a stem or underground structure on the parent plant.
Vegetative Reproduction

32. 5.5 – Multicellular Life Key Concept:
Cells work together to carry out complex functions.

33. Multicellular organisms depend on interactions among different cell types.
Tissues are groups of cells that perform a similar function.
Organs are groups of tissues that perform a specific or related function.
Organ systems are groups of organs that carry out similar functions.

34. Specialized cells perform specific functions.
Cells develop into their mature forms through the process of cell differentiation.
Cells differ because different combinations of genes are expressed.
A cell’s location in an embryo helps determine how it will differentiate.

35. Specialized cells develop from a single zygote.
Organisms are made up of specialized cells.
red blood cell
nerve cell

36. Zygotes first divide into embryonic stem cells.
Stem cells develop in two stages.
determination, or committing to become one cell type
differentiation, or acquiring specialized structures and functions

37. Specialized cells function together in tissues, organs, organ systems, and the whole organism.
Specialized cells perform specific tasks.
tissue
Tissues are groups of similar cells working together.
epithelial tissue
connective tissue
muscle tissue
nervous tissue

38. There are 11 major organ systems in the human body.

39. Ted Ed Video

40. STOP & REVIEW Specialized cells develop from a single _______. zygote
Zygotes first divide into embryonic ____________.
Stem cells
Stem cells develop in two stages.
___________, or committing to become one cell type
determination
____________, or acquiring specialized structures and functions.
differentiation
The five levels of biological organization are (in order)
Cells
Tissue
Organ
Organ System
Organism