1. Chapter 5, 6.1, & 6.2: Cell Growth and Division

2. 5.1 The Cell Cycle
KEY CONCEPT : Cells have distinct phases of growth, reproduction, and normal functions.

3. Cell Reproduction “All cells come from pre-existing cells”
Two main types of cell reproduction:
Asexual: (MITOSIS) – offspring is identical to the parent cell
Sexual: (MEIOSIS) – offspring is not identical to either parent
produces gametes (sperm and egg cells)

4. The Cell Cycle
The complete series of events from one cell division to the next.
Why Do Cells Divide?
Reproduction: new organisms are produced from parents
Growth: multicellular organisms grow by producing more cells
Repair: damaged cells are replaced by producing new cells

5. The cell cycle is a regular pattern of growth, DNA replication, and cell division.

6. The cell cycle has four main stages.
Interphase: Longest phase of the cell cycle
Gap 1 (G1): cell growth and normal functions
DNA synthesis (S): copies DNA
Gap 2 (G2): additional growth and prepares for division
Mitosis (M): includes division of the cell nucleus (mitosis) and division of the cell cytoplasm (cytokinesis)
Prophase
Metaphase
Anaphase
Telophase

7. CELL CYCLE OVERVIEW

8. Put it all together! What are the stages of cell cycle?
G1, S, G2, and Mitosis
2. What happens during G1?
Cell grows
3. What happens during S?
Replication of DNA
4. What happens during G2?
Cell Prepares to divide
5. What happens during M?
Cell divides

9. Cells divide at different rates.
The rate of cell division varies with the need for those types of cells.
Also, cells divide at different rates depending on person’s age.
Some cells are unlikely to divide (G0).

10. Cell size is limited.
A cell must be big enough to fit all the molecules and organelles it needs to live.
It also must be small enough to quickly transport nutrients and wastes into and out of the cell.
As a cell gets bigger, its volume increases faster than its surface area.

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

12. 5.2 Mitosis and Cytokinesis
KEY CONCEPT : Cells divide during mitosis and cytokinesis.

13. Chromosomes condense at the start of mitosis.
DNA double helix
DNA and histones
Chromatin
Supercoiled DNA
Each continuous ,double-stranded DNA molecule makes one chromosome.
DNA wraps around proteins called histones, forming chromatin.
Interactions between parts of the histones further compact the DNA
The chromatin coils more and more tightly around organizing proteins.

14. DNA plus proteins is called chromatin.
chromatid
telomere
centromere
One half of a duplicated chromosome is a chromatid.
Sister chromatids are held together at the centromere.
Telomeres (far ends of each chromatid) protect DNA and do not include genes.
Condensed, duplicated chromosome

15. Telomeres and Aging The Science of Aging
Cancer Risk With Telomere Length

16. Interphase Longest phase of cell cycle Interphase has 3 stages:
G1, S, & G2
The cell contains a pair of centrioles.
The cell's chromosomes have duplicated but are in the form of chromatin.
Parent cell
centrioles
spindle fibers
centrosome
nucleus with
DNA

17. Mitosis Mitosis produces 2 genetically identical daughter cells.
Mitosis divides the cell’s nucleus in four phases.
Prophase
Metaphase
Anaphase
Telophase
I remember it as PMAT

18. Prophase:
The nuclear membrane begins to disappear
chromosomes condense into chromosomes
spindle fibers form

19. 2) Metaphase:
Spindle fibers attach to centromeres
Spindle fibers line up chromosomes in the middle of the cell.

20. 3) Anaphase:
spindle fibers condense and separate sister chromatids to opposite sides of the cell.

21. 4) Telophase:
chromosomes begin to uncoil
the nuclear membrane reforms
the spindle fibers disappear
Cytokinesis, which divides the cell in two, begins.

22. Cytokinesis
Divides cytoplasm between 2 daughter cells each with genetically identical cells.
Cytokinesis differs in animal and plant cells
In animal cells, cleavage furrow separates two new nuclei
In plant cells, a cell plate forms.

23. Cytokinesis: Animal Cells & Plant Cells

25. Mitosis

26. What stage is this?

27. What stage is this?

28. What stage is this?

29. What stage is this?

30. What stage is this?

31. Mitosis

32. Elodea cells

33. Cheek cells

34. Onion Cell Mitosis

35. 5.3 Regulation of the Cell Cycle
KEY CONCEPT: Cell cycle regulation is necessary for healthy growth.

36. Internal and external factors regulate cell division.
External factors include physical and chemical signals.
Growth factors are proteins that stimulate cell division.
Most mammal cells form a single layer in a culture dish and stop dividing once they touch other cells.

37. Apoptosis is programmed cell death.
a normal feature of healthy organisms
caused by a cell’s production of self-destructive enzymes
a mechanism by which organisms limit the growth and replication of cells.
loss of apoptosis is one of the key mechanisms behind cancer.
PICTURE:

38. Cell division is uncontrolled in cancer.
Cancer cells form disorganized clumps called tumors.
Benign tumors
Remain clustered and can be removed.
Remain at the original site
Malignant tumors
metastasize, or break away, and can form more tumors.
Spread in the body
cancer cell
bloodstream
normal cell

39. Cancer cells do not carry out necessary functions.
Cancer cells come from normal cells with damage to genes involved in cell-cycle regulation.

40. Carcinogens - College Biology
Carcinogens are substances known to promote cancer.
Carcinogens - College Biology

41. Cancer Treatment Surgery: Remove tumor(s)
Radiation & Chemotherapy: used to disrupt cell division
May have undesirable side effects
Standard cancer treatments typically kill both cancerous and healthy cells

42. FYI: Number of deaths for leading causes of death
Heart disease: 597,689 Risk factors: obesity, smoking, high blood pressure & cholesterol, and diabetes
Cancer: 574,743 Lung cancer causes the most deaths among men & women, followed in women by breast cancer
Chronic lower respiratory diseases: 138,080 smoking & second hand smoking
Stroke: 129,476 Risk factors: alcohol, smoking, obesity, high blood pressure & cholesterol, and diabetes
Occurs when the blood supply to an area of the brain is obstructed, causing brain cells to die
Accidents (unintentional injuries): 120,859
Alzheimer's disease: 83,494 It’s genetics; memory problems
Diabetes: 69,071 Risk factors: obesity, old age, a family history of diabetes and not exercising
abnormally high blood sugar levels, and can lead to kidney failure, blindness, heart disease
8. Nephritis and nephrotic syndrome: 50,476
Nephritis is the inflammation of the kidneys
Nephrotic syndrome is caused by different disorders that damage the kidneys
9. Influenza and Pneumonia: 50,097 caused by a virus; A seasonal flu shot can help prevent it
10. Intentional self-harm (suicide): 38,364

43. THE TEN LEADING CAUSES OF DEATH

44. Cancer Treatments: Radiation & Chemotherapy
What is cancer?
Cancer Treatments: Radiation & Chemotherapy

45. 5.4 Asexual Reproduction
KEY CONCEPT: Many organisms reproduce by cell division.

46. Binary fission is similar in function to mitosis.
Asexual reproduction is the creation of offspring from a single parent.
Binary fission produces two daughter cells genetically identical to the parent cell.
Binary fission occurs in prokaryotes.
parent cell
DNA
duplicates
cell begins
to divide
daughter
cells

47. 5.5 Multicellular Life
KEY CONCEPT: Cells work together to carry out complex functions.

48. Multicellular organisms depend on interactions among different cell types.
vascular
tissue
leaf
stem
lateral
roots
primary
root
SYSTEMS
root system
shoot system
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.
CELL
TISSUE
ORGAN

49. organ system cells  tissues  organs 
cells tissue organ organ system organism
Lung cell  Lung tissue  Lung  Respiratory System  Person

50. 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.
Outer: skin cells
Middle: bone cells
Inner: intestines

51. Stem cells are unique body cells.
Stem cells have the ability to
divide and renew themselves
remain undifferentiated in form
develop into a variety of specialized cell types

52. Stem cells come from adults and embryos.
Adult stem cells can be hard to isolate and grow.
The use of adult stem cells may prevent transplant rejection.
The use of embryonic stem cells raises ethical issues
Embryonic stem cells can be grown indefinitely in culture.
First, an egg is fertilized by a sperm cell in a petri dish. The egg divides, forming an inner cell mass. These cells are then removed and grown with nutrients. Scientists try to control how the cells specialize by adding or removing certain molecules.

53. The use of stem cells offers many currently realized and potential benefits.
Stem cells are used to treat leukemia and lymphoma.
Stem cells may cure disease or replace damaged organs.
Stem cells may revolutionize the drug development process.

54. Trachea Grown With Stem Cells
Stem cells in bone marrow are being used to treat EB
Bone Marrow Transplant-Mayo Clinic
Trachea Grown With Stem Cells

55. 6.1 Chromosomes and Meiosis
KEY CONCEPT: Gametes have half the number of chromosomes that body cells have.

56. You have body cells and gametes.
Body cells are also called somatic cells.
Sex cells (germ cells) are called gametes.
Sex cells are located in the ovaries and testes.
Gametes are sex cells: egg and sperm.
Gametes have DNA that can be passed to offspring.
body cells
sex cells (sperm)
sex cells (egg)

57. Your cells have autosomes and sex chromosomes.
Your body cells have 23 pairs of chromosomes.
Homologous pairs of chromosomes have the same structure.
For each homologous pair, one chromosome comes from each parent.
Chromosome pairs 1-22 are autosomes.
Sex chromosomes, X and Y, determine gender in mammals.
Females: XX
Males: XY

58. Common Name
Diploid numbers (2n)
Human 46
Donkey 42
Dog 78
Cat 38
Mouse 40
Frog 26
Fruit fly 8
Corn 20
Potato 48
Yeast 32
Mold 4

59. Body cells are diploid; gametes are haploid.
Fertilization between egg and sperm occurs in sexual reproduction.
Diploid (2n) cells have two copies of
every chromosome.
Body cells are diploid.
Half the chromosomes come from each parent.

60. Haploid (n) cells have one copy of every chromosome.
Gametes are haploid.
Gametes have 22 autosomes and 1 sex chromosome.

61. Meiosis makes haploid cells from diploid cells.
Meiosis occurs in sex cells.
Meiosis produces gametes.

62. 6.2 Process of Meiosis
KEY CONCEPT : During meiosis, diploid cells undergo two cell divisions that result in haploid cells.

63. Cells go through two rounds of division in meiosis.
Meiosis reduces chromosome number and creates genetic diversity.

64. Meiosis I and meiosis II each have four phases, similar to those in mitosis.
Pairs of homologous chromosomes separate in meiosis I.
Homologous chromosomes are similar but not identical.
Sister chromatids divide in meiosis II.
Sister chromatids are copies of the same chromosome.
homologous chromosomes
sister
chromatids
sister
chromatids

65. Meiosis I occurs after DNA has been replicated.
divides homologous chromosomes in four phases.

66. Meiosis II divides sister chromatids in four phases
DNA is not replicated between meiosis I and meiosis II.

67. Meiosis differs from mitosis in significant ways.
Meiosis has two cell divisions while mitosis has one.
In mitosis, homologous chromosomes never pair up.
Meiosis results in haploid cells; mitosis results in diploid cells.

68. Haploid cells develop into mature gametes.
Gametogenesis is the production of gametes which differs between females and males.
Sperm primarily contribute DNA to an embryo.
Eggs contribute DNA, cytoplasm, and organelles to an embryo.
During meiosis, the egg gets most of the contents; the other cells form polar bodies.

69. FYI
Unlike men, who produce new sperm daily throughout most of their lifetime, women are born with all their eggs in their ovaries. To be more precise, a woman is born with about one to two million immature eggs, or follicles, in her ovaries.
Throughout her life, the vast majority of follicles will die. When a woman reaches puberty and starts to menstruate, only about 400,000 follicles remain. With each menstrual cycle, a thousand follicles are lost and only one lucky little follicle will actually mature into an egg, which is released into the fallopian tube, kicking off ovulation. That means that of the one to two million follicles, only about 400 will ever mature.
Relatively little or no follicles remain at menopause, which usually begins when a woman is between years of age. The remaining follicles are unlikely to mature and become viable eggs because of the hormonal changes that come along with menopause.

70. Meiosis http://www.youtube.com/watch?v=rB_8dTuh73c

71. Video I don’t usually show these videos, but they are on here just in case you want to use them.
The Cell cycle (5 min)
diaFormat=
Mitosis video Quiz (Full Video: 20 min)
Format=
Mitosis
2a.htm
Mitosis Rap -

72. Video I don’t usually show these videos, but they are on here just in case you want to use them.
Meiosis Video Quiz (25 min)
What is Meiosis?
Mitosis and Meiosis Animation
Sexual reproduction (30 minutes)