Mitosis/Meiosis Diagrams Ch. 12 and 13. Figure 12.7 G 2 of InterphaseProphasePrometaphase Centrosomes (with centriole pairs) Chromatin (duplicated) Nucleolus.

Mitosis/Meiosis Diagrams

Ch. 12 and 13

Figure 12.7

G2 of Interphase Prophase Prometaphase

Centrosomes(with centriole pairs)

Chromatin(duplicated)

Nucleolus Nuclearenvelope

Plasmamembrane

Early mitoticspindle

AsterCentromere

Chromosome, consistingof two sister chromatids

Fragments of nuclearenvelope

Nonkinetochoremicrotubules

Kinetochore Kinetochoremicrotubule

Metaphase

Metaphase plate

Anaphase Telophase and Cytokinesis

Spindle Centrosome atone spindle pole

Daughterchromosomes

Cleavagefurrow

Nucleolusforming

Nuclearenvelopeforming

10

m

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BioFlix: Mitosis

Figure 12.6

INTERPHASE

G1

G2

S(DNA synthesis)

MITOTIC(M) PHASE

CytokinesisM

itosi

s

Figure 12.9b

Chromosomemovement

Microtubule

Motor protein

Chromosome

Kinetochore

Tubulinsubunits

CONCLUSION

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Animation: Cytokinesis Right-click slide / select ”Play”

Figure 12.13

(a) Bacteria

(b) Dinoflagellates

(d) Most eukaryotes

Intact nuclearenvelope

Chromosomes

Microtubules

Intact nuclearenvelope

Kinetochoremicrotubule

Kinetochoremicrotubule

Fragments ofnuclear envelope

Bacterialchromosome

(c) Diatoms andsome yeasts

G1 checkpoint

G1

G2

G2 checkpointM checkpoint

M

SControlsystem

Figure 12.15

Figure 12.17

(a) Fluctuation of MPF activity and cyclin concentration during the cell cycle

(b) Molecular mechanisms that help regulate the cell cycle

MPF activityCyclinconcentration

Time

M M MS SG1G2 G1

G2 G1

Cdk

Degradedcyclin

Cyclin isdegraded

MPF

G2checkpoint

Cdk

Cyclin

M

S

G1

G 2

Figure 12.18

A sample of humanconnective tissue iscut up into smallpieces.

Enzymes digestthe extracellularmatrix, resulting ina suspension offree fibroblasts.

Cells are transferred toculture vessels.

Scalpels

Petridish

PDGF is addedto half thevessels.

Without PDGF With PDGF

10 m

1

2

3

4

Figure 12.19

Anchorage dependence

Density-dependent inhibition

Density-dependent inhibition

(a) Normal mammalian cells (b) Cancer cells

20 m 20 m

Figure 12.20

Glandulartissue

Tumor

Lymph vesselBloodvessel

Cancercell

Metastatictumor

A tumor growsfrom a singlecancer cell.

Cancer cells invade neighboringtissue.

Cancer cells spreadthrough lymph andblood vessels to other parts of the body.

Cancer cells may survive and establisha new tumor in another part of the body.

4321

Figure 13.3

Pair of homologousduplicated chromosomes

Centromere

Sisterchromatids

Metaphasechromosome

5 m

APPLICATION

TECHNIQUE

Figure 13.3b

Pair of homologousduplicated chromosomes

Centromere

Sisterchromatids

Metaphasechromosome

5 m

Figure 13.4

Sister chromatidsof one duplicatedchromosome

Key

Maternal set ofchromosomes (n 3)Paternal set ofchromosomes (n 3)

Key

2n 6

Centromere

Two nonsisterchromatids ina homologous pair

Pair of homologouschromosomes (one from each set)

Figure 13.5

Key

Haploid (n)Diploid (2n)

Egg (n)

Haploid gametes (n 23)

Sperm (n)

Ovary Testis

Mitosis anddevelopment

Diploidzygote(2n 46)

Multicellular diploidadults (2n 46)

MEIOSIS FERTILIZATION

Figure 13.8

MEIOSIS I: Separates homologous chromosomes

Prophase I Metaphase I Anaphase I Telophase I andCytokinesis

Centrosome(with centriole pair)

Sisterchromatids

Chiasmata

Spindle

Homologouschromosomes

Fragmentsof nuclearenvelope

Duplicated homologouschromosomes (red and blue)pair and exchange segments;2n 6 in this example.

Centromere(with kinetochore)

Metaphaseplate

Microtubuleattached tokinetochore

Chromosomes line upby homologous pairs.

Sister chromatidsremain attached

Homologouschromosomesseparate

Each pair of homologous chromosomes separates.

Cleavagefurrow

Two haploid cellsform; each chromosomestill consists of twosister chromatids.

MEIOSIS I: Separates sister chromatids

Prophase II Metaphase II Anaphase IITelophase II and

Cytokinesis

Sister chromatidsseparate

Haploid daughtercells forming

During another round of cell division, the sister chromatids finally separate;four haploid daughter cells result, containing unduplicated chromosomes.

Figure 13.9

Prophase

Duplicatedchromosome

MITOSIS

Chromosomeduplication

Parent cell

2n 6

Metaphase

AnaphaseTelophase

2n 2n

Daughter cellsof mitosis

MEIOSIS

MEIOSIS I

MEIOSIS II

Prophase I

Metaphase I

Anaphase ITelophase I

Haploidn 3

Chiasma

Chromosomeduplication Homologous

chromosome pair

Daughter cells of

meiosis I

Daughter cells of meiosis II

n n n n

SUMMARY

Property Mitosis Meiosis

DNAreplication

Number ofdivisions

Synapsis ofhomologouschromosomes

Number of daughter cellsand geneticcomposition

Role in the animal body

Occurs during interphase beforemitosis begins

One, including prophase, metaphase,anaphase, and telophase

Does not occur

Two, each diploid (2n) and geneticallyidentical to the parent cell

Enables multicellular adult to arise fromzygote; produces cells for growth, repair,and, in some species, asexual reproduction

Occurs during interphase before meiosis I begins

Two, each including prophase, metaphase, anaphase,and telophase

Occurs during prophase I along with crossing overbetween nonsister chromatids; resulting chiasmatahold pairs together due to sister chromatid cohesion

Four, each haploid (n), containing half as manychromosomes as the parent cell; genetically differentfrom the parent cell and from each other

Produces gametes; reduces number of chromosomesby half and introduces genetic variability among the gametes

Figure 13.10-3

Possibility 1 Possibility 2

Two equally probablearrangements ofchromosomes at

metaphase I

Metaphase II

Daughtercells

Combination 1 Combination 2 Combination 3 Combination 4

Figure 13.11-5Prophase Iof meiosis

Nonsister chromatidsheld togetherduring synapsis

Pair of homologs

Chiasma

Centromere

TEM

Anaphase I

Anaphase II

Daughtercells

Recombinant chromosomes

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Animation: Genetic Variation Right-click slide / select “Play”