Slide 1 Chapter 12: The Cell Cycle

Slide 2 Fig The Cell Cycle

Figure 12.2 (a) Reproduction (b) Growth and development (c) Tissue renewal 20  m 100  m 200  m Why do cells divide?

Figure  m Eukaryotes Have Chromosomes

Figure  m Centromere Sister chromatids Chromosomes are duplicated before cell division!

Figure Chromosomes Chromosomal DNA molecules Centromere Chromosome arm 1

Figure Chromosomes Chromosomal DNA molecules Centromere Chromosome arm Chromosome duplication (including DNA replication) and condensation Sister chromatids 1 2

Figure Chromosomes Chromosomal DNA molecules Centromere Chromosome arm Chromosome duplication (including DNA replication) and condensation Sister chromatids Separation of sister chromatids into two chromosomes 1 2 3

Slide 9 Chromosome arrangement Somatic cells – typical body cellsSomatic cells – typical body cells 46 chromosomes in 23 pairs (humans)46 chromosomes in 23 pairs (humans) The chromosomes are not normally paired upThe chromosomes are not normally paired up Each pair is called homologous chromosomesEach pair is called homologous chromosomes Gametes – sex cellsGametes – sex cells 23 chromosomes (humans)23 chromosomes (humans) One member from each pairOne member from each pair

Slide 10 Homologous chromosomes 22 of the pairs (autosomes) are “true homologues”22 of the pairs (autosomes) are “true homologues” One of each came from mom and dadOne of each came from mom and dad Identical in length and type of genes carriedIdentical in length and type of genes carried Genes on each are slightly differentGenes on each are slightly different Sex chromosomes (23rd pair) don’t match up exactly (X vs Y)Sex chromosomes (23rd pair) don’t match up exactly (X vs Y)

Figure 13.3b Pair of homologous duplicated chromosomes Centromere Sister chromatids Metaphase chromosome 5  m

Figure 12.6 INTERPHASE G1G1 G2G2 S (DNA synthesis) MITOTIC (M) PHASE Cytokinesis Mitosis The Cell Cycle

Slide 13 Mitosis Division of the nucleusDivision of the nucleus Results in two nuclei that have the same chromosome number as the parentResults in two nuclei that have the same chromosome number as the parent The two nuclei are genetically identicalThe two nuclei are genetically identical

Slide 14 Mitosis Divided into 5 phases:Divided into 5 phases: 1.Prophase 2.Prometaphase 3.Metaphase 4.Anaphase 5.Telophase Phases are determined by chromosome movementPhases are determined by chromosome movement Chromosome movement determined by mitotic spindleChromosome movement determined by mitotic spindle Mitotic spindle controlled by centrosomeMitotic spindle controlled by centrosome

Figure 12.8 Sister chromatids Aster Centrosome Metaphase plate (imaginary) Kineto- chores Overlapping nonkinetochore microtubules Kinetochore microtubules Microtubules Chromosomes Centrosome 0.5  m 1  m The Mitotic Spindle

Figure 12.7a G 2 of Interphase Prophase Prometaphase Centrosomes (with centriole pairs) Chromatin (duplicated) Nucleolus Nuclear envelope Plasma membrane Early mitotic spindle Aster Centromere Chromosome, consisting of two sister chromatids Fragments of nuclear envelope Nonkinetochore microtubules Kinetochore Kinetochore microtubule

Figure 12.7b Metaphase Metaphase plate Anaphase Telophase and Cytokinesis Spindle Centrosome at one spindle pole Daughter chromosomes Cleavage furrow Nucleolus forming Nuclear envelope forming

Figure 12.7c G 2 of Interphase Prophase Prometaphase 10  m

Figure 12.7d 10  m MetaphaseAnaphase Telophase and Cytokinesis

Figure Chromatin condensing Nucleus NucleolusChromosomes Cell plate 10  m Prophase Prometaphase Metaphase Anaphase Telophase Mitosis in a Plant Cell

Figure (a) Cleavage of an animal cell (SEM) (b) Cell plate formation in a plant cell (TEM) Cleavage furrow Contractile ring of microfilaments Daughter cells Vesicles forming cell plate Wall of parent cell Cell plate New cell wall Daughter cells 100  m 1  m Cytokenesis: Animal vs. Plant Cell

Figure Binary Fission: Cell division in bacteria

Figure Origin of replication E. coli cell Two copies of origin Cell wall Plasma membrane Bacterial chromosome Chromosome replication begins.

Figure Origin of replication E. coli cell Two copies of origin Cell wall Plasma membrane Bacterial chromosome Origin Chromosome replication begins. Replication continues. 2

Figure Origin of replication E. coli cell Two copies of origin Cell wall Plasma membrane Bacterial chromosome Origin Chromosome replication begins. Replication continues. Replication finishes. 2 3

Figure Origin of replication E. coli cell Two copies of origin Cell wall Plasma membrane Bacterial chromosome Origin Chromosome replication begins. Replication continues. Replication finishes. Two daughter cells result

Slide 27 LE 8-3b Prokaryotic chromosomes Colorized TEM 32,500 

Figure G 1 checkpoint G1G1 G2G2 G 2 checkpoint M checkpoint M S Control system Cell Cycle Control

Figure G 1 checkpoint G1G1 G1G1 G0G0 (a) Cell receives a go-ahead signal. (b) Cell does not receive a go-ahead signal. Checkpoints

Slide 30 Cancer Kills 1 out of 5 AmericansKills 1 out of 5 Americans Disease of the cell cycleDisease of the cell cycle Cells don’t respond to the normal cell cycle checkpointsCells don’t respond to the normal cell cycle checkpoints Cancer cells DO NOT exhibit density or anchorage dependenceCancer cells DO NOT exhibit density or anchorage dependence Cancer cells divide out of control and can invade other parts of the bodyCancer cells divide out of control and can invade other parts of the body

Figure Anchorage dependence Density-dependent inhibition (a) Normal mammalian cells (b) Cancer cells 20  m

Figure Glandular tissue Tumor Lymph vessel Blood vessel Cancer cell Metastatic tumor A tumor grows from a single cancer cell. Cancer cells invade neighboring tissue. Cancer cells spread through lymph and blood vessels to other parts of the body. Cancer cells may survive and establish a new tumor in another part of the body. 4321

Figure 12.UN01 Mitosis Cytokinesis MITOTIC (M) PHASE G1G1 G2G2 S Telophase and Cytokinesis Anaphase Metaphase Prometaphase Prophase I T R HA S E E P N

Figure 12.UN05

Figure 12.UN04