CAMPBELL BIOLOGY IN FOCUS © 2014 Pearson Education, Inc. Urry Cain Wasserman Minorsky Jackson Reece Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge 9 The Cell Cycle

© 2014 Pearson Education, Inc. Figure 9.1

© 2014 Pearson Education, Inc. Figure 9.2 (a) Reproduction 100  m (c) Tissue renewal (b) Growth and development 200  m 20  m

Cellular Organization of the Genetic Material  All the DNA in a cell constitutes the cell’s genome  A genome can consist of a single DNA molecule (common in prokaryotic cells) or a number of DNA molecules (common in eukaryotic cells)  DNA molecules in a cell are packaged into chromosomes © 2014 Pearson Education, Inc.

Figure 9.3 Eukaryotic chromosomes 20  m

© 2014 Pearson Education, Inc. Figure 9.4 Centromere 0.5  m Sister chromatids

© 2014 Pearson Education, Inc. Figure Centromere Chromosomal DNA molecules Chromosomes Chromosome arm 1

© 2014 Pearson Education, Inc. Figure Centromere Sister chromatids Chromosomal DNA molecules Chromosomes Chromosome arm Chromosome duplication 1 2

© 2014 Pearson Education, Inc. Figure Centromere Sister chromatids Separation of sister chromatids Chromosomal DNA molecules Chromosomes Chromosome arm Chromosome duplication 1 3 2

© 2014 Pearson Education, Inc. Figure 9.6 Cytokinesis Mitosis S (DNA synthesis) G1G1 G2G2

© 2014 Pearson Education, Inc. Figure 9.UN03

© 2014 Pearson Education, Inc. Video: Animal Mitosis Video: Microtubules Mitosis Animation: Mitosis Video: Microtubules Anaphase Video: Nuclear Envelope

© 2014 Pearson Education, Inc. Figure 9.7f G 2 of Interphase 10  m

© 2014 Pearson Education, Inc. Figure 9.7g Prophase 10  m

© 2014 Pearson Education, Inc. Figure 9.7h Prometaphase 10  m

© 2014 Pearson Education, Inc. Figure 9.7i 10  m Metaphase

© 2014 Pearson Education, Inc. Figure 9.7j Anaphase 10  m

© 2014 Pearson Education, Inc. Figure 9.7k Telophase and Cytokinesis 10  m

© 2014 Pearson Education, Inc. Figure 9.11a 10  m Nucleus Nucleolus Chromosomes condensing Prophase 1

© 2014 Pearson Education, Inc. Figure 9.11b 10  m 2 Prometaphase Chromosomes

© 2014 Pearson Education, Inc. Figure 9.11c 10  m 3 Metaphase

© 2014 Pearson Education, Inc. Figure 9.11d 10  m 4 Anaphase

© 2014 Pearson Education, Inc. Figure 9.11e 10  m 5 Telophase Cell plate

© 2014 Pearson Education, Inc. Figure 9.14 G 1 nucleus immediately entered S phase and DNA was synthesized. Experiment Experiment 1 Experiment 2 Results S S S M G1G1 M M G1G1 G 1 nucleus began mitosis without chromosome duplication. Conclusion Molecules present in the cytoplasm control the progression to S and M phases.

© 2014 Pearson Education, Inc. Figure 9.15 M checkpoint S M G1G1 G2G2 G 1 checkpoint G 2 checkpoint Control system

© 2014 Pearson Education, Inc. Figure 9.16a G1G1 G 1 checkpoint Without go-ahead signal, cell enters G 0. G0G0 With go-ahead signal, cell continues cell cycle. (a) G 1 checkpoint G1G1

 The cell cycle is regulated by a set of regulatory proteins and protein complexes including kinases and proteins called cyclins © 2014 Pearson Education, Inc.

 An example of an internal signal occurs at the M phase checkpoint  In this case, anaphase does not begin if any kinetochores remain unattached to spindle microtubules  Attachment of all of the kinetochores activates a regulatory complex, which then activates the enzyme separase  Separase allows sister chromatids to separate, triggering the onset of anaphase © 2014 Pearson Education, Inc.

Figure A sample of human connective tissue is cut up into small pieces. Petri dish Scalpels

© 2014 Pearson Education, Inc. Figure A sample of human connective tissue is cut up into small pieces. 2 Enzymes digest the extracellular matrix, resulting in a suspension of free fibroblasts. Petri dish Scalpels

© 2014 Pearson Education, Inc. Figure A sample of human connective tissue is cut up into small pieces. 2 3 Enzymes digest the extracellular matrix, resulting in a suspension of free fibroblasts. Cells are transferred to culture vessels. Petri dish Scalpels 4 PDGF is added to half the vessels.

© 2014 Pearson Education, Inc. Figure A sample of human connective tissue is cut up into small pieces Enzymes digest the extracellular matrix, resulting in a suspension of free fibroblasts. Cells are transferred to culture vessels. PDGF is added to half the vessels. Without PDGF With PDGF Cultured fibroblasts (SEM) 10  m Petri dish Scalpels

 Another example of external signals is density- dependent inhibition, in which crowded cells stop dividing  Most animal cells also exhibit anchorage dependence, in which they must be attached to a substratum in order to divide  Cancer cells exhibit neither density-dependent inhibition nor anchorage dependence © 2014 Pearson Education, Inc.

Figure 9.18 Anchorage dependence: cells require a surface for division 20  m Density-dependent inhibition: cells divide to fill a gap and then stop Density-dependent inhibition: cells form a single layer 20  m (a) Normal mammalian cells (b) Cancer cells

© 2014 Pearson Education, Inc. Figure 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. A small percentage of cancer cells may metastasize to another part of the body. Breast cancer cell (colorized SEM) Lymph vessel Blood vessel Cancer cell Metastatic tumor Glandular tissue Tumor 5  m 2 3 4

© 2014 Pearson Education, Inc. Figure 9.19a 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. Glandular tissue Tumor 1 23

© 2014 Pearson Education, Inc. Figure 9.19b 43 Cancer cells spread through lymph and blood vessels to other parts of the body. A small percentage of cancer cells may metastasize to another part of the body. Lymph vessel Blood vessel Cancer cell Metastatic tumor

© 2014 Pearson Education, Inc. Figure 9.UN02 S G1G1 G2G2 Mitosis Telophase and Cytokinesis MITOTIC (M) PHASE Anaphase Metaphase Prometaphase Prophase