Objectives:

Identify steps of cell cycle

Catalyst: Make a T-chart for prokaryotic and eukaryotic cells.

TODAYTODAY

I Present – you take down infoI Present – you take down info Let’s Practice TogetherLet’s Practice Together

– Two quick Practice SheetsTwo quick Practice Sheets– Utilizing selector toolUtilizing selector tool

Then you prove your Then you prove your knowledge!!!!!knowledge!!!!!– WhiteboardsWhiteboards– FlipbookFlipbook

How many cells do we begin with?

1

How do we get more?

A: Go to Wal-MartB: Email Mr. LandC: Cellular Division

process by which cells reproduce themselves

CELL DIVISION

Cell Cycle

The time it takes a cell to reproduce varies depending on cell type

CELLS & George Wythe

Why would a cell divide?Why is the school divided by grade

levels?

How do cells get water and energy?Why must we have multiple lunch

shifts?

All cells except sex cells

produces cells with the exact same DNA

and characteristics

MITOSIS

Binary Fission Bacteria replicate its chromosomes and then

divides in two

Budding Little buds sprout from parent and then grow up

– same chromosomes

Sporulation Fungi produces spores that are released into

the air – same chromosomes

CELL CYCLE 2 Stages

Cell Division

Cell Division

InterphaseInterphase

INTERPHASE

G1 PHASE•“gap 1” Phase

• period when cell growth and development occur

S PHASE•“synthesis” Phase

• DNA replication / synthesis occurs

G2 PHASE• “gap 2” Phase• when organelles needed in

cell division are made (centrioles, spindle fibers)

CELL CYCLE 2 Stages

Cell Division

Cell Division

InterphaseInterphase

Cell Division

M Phase

(Mitosis)

CELL Division is composed of 2 separate stages

Cytokinesis(division of cytoplasm)

Back to Interphase

MNEMONIC DEVICE!!! REMEMBER!!

What happens if Mr. Gibney drinks 4 bottles of gatorade and chills on the couch for an hour.

He gets up and goes to the bathroom and is in such a hurry that he kinda misses.

PMAT

PROPHASEPROPHASEMETAPHASEMETAPHASEANOPHASEANOPHASETELOPHASETELOPHASE

1. PROPHASE1. PROPHASE longest phaselongest phaseChromosomes Chromosomes

appear & attach to appear & attach to spindlespindle

Nucleolus and Nucleolus and nuclear membrane nuclear membrane breaks downbreaks down

2. METAPHASE2. METAPHASEShortest phaseShortest phaseChromosomes line up Chromosomes line up

at center of the cellat center of the cell

3. ANAPHASE3. ANAPHASECentromeres splitCentromeres splitChromosomes Chromosomes

separate to become separate to become individualsindividuals

Ends when the Ends when the movement of movement of chromosomes stopschromosomes stops

4. TELOPHASE4. TELOPHASEChromosomes uncoil Chromosomes uncoil

into chromatininto chromatinNuclear membrane Nuclear membrane

reformsreformsSpindle breaks apartSpindle breaks apart

Division of the cytoplasm of the cell

CYTOKINESIS

Meiosis

Humans have 23 pairs of chromosomes for a total of 46 chromosomes

Chromosomes exist in pairs called homologuesDiploid cells have two sets of chromosomes –

Ex: all cells (skin, hair, eye) except for sex cellsHaploid cells have one half the chromosomes –

Ex: only sex cells

Sex cells are also called gametesMeiosis is the process by which sex cells

make sure they have the right number of chromosomes

Meiosis takes place in the gonads: testes and ovaries

Sex ChromosomesWomen:

Men:

Many women ask why oh “y”

XX

Xy

Diploid!!

Haploid or Diploid

Haploid!!

Haploid!!

MeiosisThe process of cell division so that each new cell has 1/2 the number of chromosomes as the original.

MITOSIS MEIOSISCell Divides

Once

Results in 2 cells with 46 Chromosomes

• Cell Divides Twice

• Results in cells with 23 Chromosomes

• Makes 4 sperm cells or 1 egg cell

Stages of Meiosis

The stages of Meiosis in order are: Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, and Telophase II

Spermatogenesis – makes four sperm cells from each parent cell

Oogenesis – makes one ovum and three polar bodies from each parent cell (polar bodies are discarded)

PRACTICE!!!!!

I’ve Presented – you’ve taken down infoLet’s Practice Together

Two quick Practice Sheets Utilizing selector tool

Then you prove your knowledge!!!!! Whiteboards Flipbook

WHITEBOARD PRACTICE

POD Group Competitions

G1 PHASE•This is the period when cell growth and development occur

CELL CYCLE 2 Stages

?

Cell Division

Interphase?

S PHASE• DNA replication / synthesis occurs

•Part of interphase

1. PROPHASE1. PROPHASE longest phaselongest phaseChromosomes Chromosomes

appear & attach to appear & attach to spindlespindle

Nucleolus and Nucleolus and nuclear membrane nuclear membrane breaks downbreaks down

G2 PHASE• when organelles needed in

cell division are made (centrioles, spindle fibers)

3. ANAPHASE3. ANAPHASECentromeres splitCentromeres splitChromosomes Chromosomes

separate to become separate to become individualsindividuals

Ends when the Ends when the movement of movement of chromosomes stopschromosomes stops

Cell Division

CELL Division is composed of 2 separate stages

Back to Interphase

2. METAPHASE2. METAPHASEShortest phaseShortest phaseChromosomes line up Chromosomes line up

at center of the cellat center of the cell

Division of the cytoplasm of the cell

CYTOKINESIS

4. TELOPHASE4. TELOPHASEChromosomes uncoil Chromosomes uncoil

into chromatininto chromatinNuclear membrane Nuclear membrane

reformsreformsSpindle breaks apartSpindle breaks apart

Meiosis

Humans have pairs of chromosomesFor a total of chromosomesChromosomes exist in pairs called

23

46

Homologues

Sex ChromosomesWomen:

Men:

Many women ask why oh “y”

XX

Xy

Diploid!!

Haploid or Diploid

Haploid!!

Haploid!!

MITOSIS MEIOSISCell Divides

Once

Results in 2 cells with 46 Chromosomes

• Cell Divides Twice

• Results in cells with 23 Chromosomes

• Makes 4 sperm cells or 1 egg cell

Stages of Meiosis

– makes four sperm cells from each parent cell

– makes one ovum and three polar bodies from each parent cell (polar bodies are discarded)

spermatogenesis

oogenesis

THE FUNDAMENTAL RELATIONSHIP

Chromosome Gene Message Product

(DNA) (mRNA) (protein)

Flipbook

You have 9 cardsFirst card = Flip book of Cellular Division

plus your nameCard 1 – G1 (write definition) - InterphaseCard 2 – S Phase - Interphase, Card 3 –

G2 - InterphaseCard 4-8 – do phases of mitosis plus draw

pictures

Cancer is a disease Cancer is a disease of cells and genes.of cells and genes.

Navajo word for cancer translates as:Navajo word for cancer translates as:

The sore that will not The sore that will not heal.heal.

Per year in the United States alone:Per year in the United States alone:

over 1.2 million new cases (150/hour) over 1.2 million new cases (150/hour)

over over ½ million deaths (25% of all ½ million deaths (25% of all deaths)deaths)

more than $50 billion spent for more than $50 billion spent for healthcarehealthcare

about $15 billion spent for researchabout $15 billion spent for research

“Cigarette smoking is the most significant cause of lung cancer and the leading cause of lung cancer death in both men and women. Smoking is also responsible for most cancers of the larynx, oral cavity, and esophagus. In addition, it is highly associated with the development of and deaths from bladder, kidney, pancreatic, and cervical cancers.” National Cancer Institute

Cancer is a complex genetic disease caused primarily by environmental factorsNote well:Note well: “genetic” is not the same as “inherited”

(most cancers are not usually inherited)

Tumor = Neoplasm = Growing mass of cells

1) Benign

2) Malignant

invasive

metastatic

21_44_Tumors.jpg

21_42_metastasis.jpg

Transplantable keratoma

BENIGN

Ameloblastoma

Adult viral-induced renal Adult viral-induced renal adenocarcinoma grafted to the back of adenocarcinoma grafted to the back of

a tadpolea tadpole

MALIGNANTMALIGNANT

Carcinoma = epithelial

Sarcoma = connective tissue or muscle

Blood = leukemias

Brain and Nerve

time

Normal

Malignant

Hamster cells in tissue culture

Normal Cells Cancer Cells

Scanning Electron Microscopy (SEM) of cells growing in tissue culture

Human karyotype

Normal Cancer

Human lung cancer cells in tissue culture have become multi-nucleate

Six features common to cancer cells from: Hanahan, D. and R.A. Weinberg (2000) “The Hallmarks of Cancer,” Cell

100:57-70

1. Self-sufficiency in growth signals or response2. Insensitivity to growth inhibitory signals

3. Evasion of programmed cell death

4. Limitless replication potential

5. Sustained stimulation of blood vessel growth6. Tissue invasion and metastasis

Mainly: loss of control of cell division

Three probable causes of cancer

1. Defective DNA repair mechanisms2. Transformation of a normal gene into an oncogene

3. Malfunction of a tumor suppressor gene

Healthy, dividing cell

Damage to cell

Damage control Stop cell division Assess damage Cellular repair

Successful repair

Return toReturn to cell cyclecell cycle

Failed repair

CancerCancer

Extensive damage

Cell deathCell deathmodified from Biology of Cancer by R.W. Phillis and S. Goodwin

Cancer results from mutations, often environmentally

induced, in genes that stimulate

or suppress cell division and cell-to-cell signaling.

These genes commonly code for transcription factors and

other genetic control elements.

““While much is known While much is known about the science of about the science of

cancer, its prevention cancer, its prevention depends largely, if not depends largely, if not exclusively, on political exclusively, on political

action.”action.”S. Epstein, University of Illinois Medical Center