Campbell's Biology Ch 12

Front 1

Cell Cycle

Back 1

Key roles of cell division

The Cell Theory

Front 2

The Cell Theory

Back 2

All organisms are composed of cells
Cells are the basic unit of structure and function
All cells come from pre-existing cells.

Front 3

Creation of cells in UNICELLULAR organisms

Back 3

1) Reproduction
(Mitosis)
Two cells created just like the first cell.

Creates whole organism

Front 4

Creation of cells in MULTICELLULAR organisms

Back 4

1) Growth and Development
2) Tissue Renewal and Repair
3) Reproduction

Front 5

Mitosis

Back 5

Concept 12.1
Most cell division results in genetically identical daughter cells
Cell division part of the cell cycle

Front 6

Cellular Organization of Genetic Material

Back 6

1) Genome
2) Prokaryotes
3) Eukaryotes

Front 7

Genome

Back 7

Cell's or organism's genetic material

Front 8

Prokaryotes

Back 8

Single DNA molecule
Circular chromosome

Front 9

Eukaryotes

Back 9

Multiple, Linear, DNA molecules
Linear chromosomes

Front 10

Vast amount of human DNA

Back 10

"A typical human cell, for example, has about 2m of DNA -- a length about 250,000 times greater than the cell's diameter. Yet before the cell can divide, all of this DNA must be copied"

ACCURATELY

Front 11

Cellular organization of Genetic Material

Back 11

Chromosome (100s-1,000s genes)

Somatic Cells (46 chromosomes)

Gametes (23 chromosomes)
-Egg cells and sperm cells

Front 12

Chromatin

Back 12

In Eukaryotes
-Contains both DNA and associated proteins

Front 13

Distribution of Chromosomes during Cell Division

Back 13

1) Before division
-Chromatin
2) After DNA duplicated
-Chromosomes condense

Front 14

Duplicated Chromosome

Back 14

SISTER CHROMATIDS attached at CENTROMERE
--Still only counts as one chromosome

--> Separate during division
--Now individual chromosomes

Front 15

Mitosis definition

Back 15

Division of the nucleus

Front 16

Cytokinesis

Back 16

Division of the cytoplasm

Front 17

Meiosis definition

Back 17

Nonidentical daughter cells

Gamete formation (46 --> 23)

Front 18

Cell cycle time

Back 18

Normal cell (hours)
Embryonic cell (minutes)

Front 19

Cell Cycle

Back 19

Interphase
Prophase
Prometaphase
Metaphase
Anaphase
Telophase

Front 20

Interphase

Back 20

Alternates with the mitotic phase
DNA DUPLICATION

Subphases: (proteins and cytoplasmic organelles)
G1 -- Growth
S -- Replication
G2

90% of time in interphase

Front 21

G2 Interphase

Back 21

1) Nuclear envelope
2) Nucleoli
3) Centrosome
4) Uncondensed Chromosomes

Front 22

G2 Interphase Image

Back 22

Front 23

Prophase

Back 23

1) Nuclear Envelope
2) Condensed, discrete chromosomes (sister chromatids)
3) Nucleoli disappear
4) Mitotic Spindle begins to form
5) Centrosomes move away from each other

Front 24

Mitotic Spindle

Back 24

Comes from centrosomes (microtubule organizing centers)

Microtubules assemble from centrosomes

Front 25

Prophase Image

Back 25

Front 26

Prometaphase

Back 26

1) Nuclear Envelope Fragments
2) Microtubules can invade nuclear area
3) Chromosomes more condensed
4) Chromatids have kinetochores
5) Kinetochore and Nonkinetochore microtubules

Front 27

Kinetochore Stuff

Back 27

Kinetochore- PROTEINS associated with DNA

Kinetochore microtubules- (spindle microtubules)
Chromosome walking (motor proteins)
Tug of war, line chromosomes up at metaphase plate
Depolymerization (kinetochore end)
Pulls chromosomes from metaphase place to poles

Front 28

Prometaphase Image

Back 28

Front 29

Metaphase

Back 29

1) Centrosomes at opposite poles of cell
2) Metaphase Plate
3) Each kinetochore is attached to a kinetochore microtubule

Front 30

Metaphase Image

Back 30

Front 31

Anaphase

Back 31

SHORTEST STAGE OF MITOSIS
1) Cohesin Proteins cleaved
(Sister chromatids part suddenly)
2) Daughter chromosomes move toward opposite ends (centromere first)
3) Kinetochore microtubules shorten
4) Nonkinetochore microtubules lengthen

Front 32

Nonkinetochore Microtubules

Back 32

Overlap with those from other poles
Motor proteins walk them away from each other
Polymerization at overlapping ends
Elongate cell during Anaphase

Front 33

Anaphase Image

Back 33

Front 34

Telophase

Back 34

1) Daughter Nuclei Form
2) Nucleoli reappear
3) Chromosome less condensed
Spindle depolymerized

Ends Mitosis

Front 35

Telophase Image

Back 35

Front 36

Cytokinesis

Back 36

Division of cytoplasm

Cleavage furrow (animal cells)
Actin microfilaments (like purse string)

Front 37

Plant Cytokinesis

Back 37

Cell plate
Vesicles from Golgi--Membrane fuses with plasma membranes

Front 38

Binary Fission

Back 38

Cell replication in Prokaryotes (bacteria)
Singular circular chromosome
DNA duplication

Front 39

Cell cycle control system

Back 39

Regulated at checkpoints (regulatory proteins survey cell)

G1 checkpoint
1) Go ahead (S, G2, M phases)
2) No go-ahead (G0)

**Most cells G0 phase**

Front 40

Stop and Go Signs at checkpoints

Back 40

1) Growth Factors
proteins
2) Density-dependent inhibition
contact and nutrients
3) Anchorage Dependence
attachment to substratum

Front 41

Cancer

Back 41

Loss of cell cycle controls
NO density-dependent inhibition
NO anchorage dependence

Front 42

Tumor

Back 42

Mass of cells either:

1) Benign (cells remain in place)
2) Malignant (cells become invasive)
3) Metastasis
Cells spread throughout body (blood and lymph)
Secondary tumors

Front 43

Regulatory proteins and genes

Back 43

Regulatory proteins normal: cell division regulated

Regulatory genes (DNA --> proteins)
Proto-oncogenes ("go")
Tumor suppressor genes ("stop")

Transformation
Gene mutations --> abnormal proteins
Proto-oncogenes --> oncogenes "GOOOOOO"
No tumor suppressor genes

Front 44

Cancer: Multistep process

Back 44

Mutations in regulatory genes
Multiple mutations in a SINGLE cell

Carcinogens
1) Smoking
2) UV light
3) Asbestos
4) Viruses

--Can be predisposed (inherited mutations)