Fig. 8-00

Fig. 8-00a

Fig. 8-00b

Fig. 8-1a Cell Replacement Growth via Cell Division FUNCTIONS OF CELL DIVISION Human kidney cell Early human embryo LM Colorized TEM

Fig. 8-1aa Cell Replacement Colorized TEM

Fig. 8-1ab Growth via Cell Division LM

Fig. 8-1b Asexual Reproduction FUNCTIONS OF CELL DIVISION Sea stars LM Amoeba African Violet

Fig. 8-1ba LM Asexual Reproduction

Fig. 8-1bb Asexual Reproduction

Fig. 8-1bc Asexual Reproduction

Fig. 8-2 Number of chromosomes in body cells Indian muntjac deer Species Opossum Koala Human Mouse Giraffe Buffalo Dog Red viscacha rat Duck-billed platypus

Fig. 8-3 Chromosomes LM

Fig. 8-4 Duplicated chromosomes (sister chromatids) TEM Tight helical fiber Looped domains TEM Centromere Nucleosome “Beads on a string” Histones DNA double helix

Fig. 8-4a TEM Nucleosome “Beads on a string” Histones DNA double helix

Fig. 8-4b Duplicated chromosomes (sister chromatids) TEM Tight helical fiber Looped domains Centromere

Fig. 8-5 Chromosome duplication Sister chromatids Chromosome distribution to daughter cells

Fig. 8-6 Cytokinesis (division of cytoplasm) Mitosis (division of nucleus) Mitotic (M) phase: cell division (10% of time) Interphase: metabolism and growth (90% of time) S phase (DNA synthesis; chromosome duplication) G1G1 G2G2

Fig. 8-7a Nuclear envelope LM Plasma membrane Chromosome, consisting of two sister chromatids Spindle microtubules Fragments of nuclear envelope Centrosome Centromere Early mitotic spindle Centrosomes (with centriole pairs) Chromatin PROPHASEINTERPHASE

Fig. 8-7aa Nuclear envelope Plasma membrane Chromosome, consisting of two sister chromatids Spindle microtubules Fragments of nuclear envelope Centrosome Centromere Early mitotic spindle Centrosomes (with centriole pairs) Chromatin PROPHASE INTERPHASE

Fig. 8-7ab INTERPHASE LM

Fig. 8-7ac LM PROPHASE

Fig. 8-7ad LM PROPHASE

Fig. 8-7b ANAPHASE METAPHASE TELOPHASE AND CYTOKINESIS Spindle Daughter chromosomes Cleavage furrow Nuclear envelope forming

Fig. 8-7ba ANAPHASE METAPHASE TELOPHASE AND CYTOKINESIS Spindle Daughter chromosomes Cleavage furrow Nuclear envelope forming

Fig. 8-7bb METAPHASE

Fig. 8-7bc ANAPHASE

Fig. 8-7bd TELOPHASE AND CYTOKINESIS

Fig. 8-8a Cleavage furrow SEM Cleavage furrow Contracting ring of microfilaments Daughter cells

Fig. 8-8aa Cleavage furrow SEM

Fig. 8-8ab Cleavage furrow Contracting ring of microfilaments Daughter cells

Fig. 8-8b Daughter cells New cell wall Vesicles containing cell wall material Cell plate Cell wall Wall of parent cell Cell plate forming Daughter nucleus LM

Fig. 8-8ba Wall of parent cell Cell plate forming Daughter nucleus LM

Fig. 8-8bb Daughter cells New cell wall Vesicles containing cell wall material Cell plate Cell wall

Fig. 8-9 A tumor grows from a single cancer cell. Cancer cells invade neighboring tissue. Metastasis: Cancer cells spread through lymph and blood vessels to other parts of the body. Glandular tissue Blood vessel Tumor Lymph vessels

Fig. 8-10

Fig Pair of homologous chromosomes LM One duplicated chromosome Centromere Sister chromatids

Fig. 8-11a LM

Fig Multicellular diploid adults (2n  46) MEIOSIS FERTILIZATION MITOSIS 2n2n and development Key Sperm cell n n Diploid zygote (2n  46) Diploid (2n) Haploid (n) Egg cell Haploid gametes (n  23)

Fig INTERPHASE BEFORE MEIOSIS Sister chromatids Duplicated pair of homologous chromosomes Chromosomes duplicate. Pair of homologous chromosomes in diploid parent cell

Fig MEIOSIS I Homologous chromosomes separate. INTERPHASE BEFORE MEIOSIS Sister chromatids Duplicated pair of homologous chromosomes Chromosomes duplicate. Pair of homologous chromosomes in diploid parent cell

Fig MEIOSIS I Sister chromatids separate. MEIOSIS II Homologous chromosomes separate. INTERPHASE BEFORE MEIOSIS Sister chromatids Duplicated pair of homologous chromosomes Chromosomes duplicate. Pair of homologous chromosomes in diploid parent cell

Fig. 8-14a MEIOSIS I: HOMOLOGOUS CHROMOSOMES SEPARATE Sister chromatids remain attached Pair of homologous chromosomes INTERPHASE Sister chromatids Homologous chromosomes pair up and exchange segments. Chromosomes duplicate. Pairs of homologous chromosomes line up. Pairs of homologous chromosomes split up. Nuclear envelope Chromatin Centromere Microtubules attached to chromosome Sites of crossing over Spindle Centrosomes (with centriole pairs) PROPHASE IMETAPHASE I ANAPHASE I

Fig. 8-14aa INTERPHASE Nuclear envelope Chromatin Centrosomes (with centriole pairs)

Fig. 8-14ab TELOPHASE I AND CYTOKINESIS Sister chromatids remain attached Pair of homologous chromosomes Sister chromatids Centromere Microtubules attached to chromosome Sites of crossing over Spindle PROPHASE IMETAPHASE I ANAPHASE I Cleavage furrow

Fig. 8-14ac Pair of homologous chromosomes Sister chromatids Centromere Microtubules attached to chromosome Sites of crossing over Spindle PROPHASE I METAPHASE I

Fig. 8-14ad TELOPHASE I AND CYTOKINESIS Sister chromatids remain attached ANAPHASE I Cleavage furrow

Fig. 8-14b TELOPHASE II AND CYTOKINESIS Sister chromatids separate ANAPHASE II Cleavage furrow TELOPHASE I AND CYTOKINESIS Two haploid cells form; chromosomes are still doubled. MEIOSIS II: SISTER CHROMATIDS SEPARATE PROPHASE IIMETAPHASE II During another round of cell division, the sister chromatids finally separate; four haploid daughter cells result, containing single chromosomes. Haploid daughter cells forming

Fig. 8-14ba TELOPHASE II AND CYTOKINESIS Sister chromatids separate ANAPHASE II PROPHASE II METAPHASE II Haploid daughter cells forming

Fig. 8-14bb PROPHASE II METAPHASE II

Fig. 8-14bc LM

Fig. 8-14bd TELOPHASE II AND CYTOKINESIS Sister chromatids separate ANAPHASE II Haploid daughter cells forming

Fig Duplicated chromosome (two sister chromatids) MITOSIS Prophase Chromosome duplication Chromosomes align at the middle of the cell. Metaphase Sister chromatids separate during anaphase. Anaphase Telophase Daughter cells of mitosis 2n2n 2n2n Prophase I Metaphase I Anaphase I Telophase I MEIOSIS Chromosome duplication Homologous chromosomes come together in pairs. MEIOSIS I Site of crossing over between homologous (nonsister) chromatids Homologous pairs align at the middle of the cell. Chromosome with two sister chromatids Homologous chromosomes separate during anaphase I; sister chromatids remain together. Daughter cells of meiosis I Sister chromatids separate during anaphase II. Haploid n  2 MEIOSIS II Parent cell (before chromosome duplication) 2n  4 Daughter cells of meiosis II n n n n

Fig. 8-15a Duplicated chromosome (two sister chromatids) MITOSIS Prophase Chromosome duplication Chromosomes align at the middle of the cell. Metaphase Prophase I Metaphase I MEIOSIS Chromosome duplication Homologous chromosomes come together in pairs. MEIOSIS I Site of crossing over between homologous (nonsister) chromatids Homologous pairs align at the middle of the cell. Parent cell (before chromosome duplication) 2n  4

Fig. 8-15b Sister chromatids separate during anaphase. Anaphase Telophase Daughter cells of mitosis 2n2n 2n2n Anaphase I Telophase I Chromosome with two sister chromatids Homologous chromosomes separate during anaphase I; sister chromatids remain together. Daughter cells of meiosis I Sister chromatids separate during anaphase II. Haploid n  2 MEIOSIS II Daughter cells of meiosis II n n n n

Fig Metaphase of meiosis I POSSIBILITY 1 POSSIBILITY 2

Fig Metaphase of meiosis I Metaphase of meiosis II POSSIBILITY 1 POSSIBILITY 2

Fig Metaphase of meiosis I Metaphase of meiosis II Combination a POSSIBILITY 1 POSSIBILITY 2 Combination bCombination c Combination d Gametes

Fig. 8-17

Fig Prophase I of meiosis Duplicated pair of homologous chromosomes

Fig Homologous chromatids exchange corresponding segments. Prophase I of meiosis Duplicated pair of homologous chromosomes Chiasma, site of crossing over

Fig Metaphase I Homologous chromatids exchange corresponding segments. Sister chromatids remain joined at their centromeres. Prophase I of meiosis Duplicated pair of homologous chromosomes Chiasma, site of crossing over Spindle microtubule

Fig Metaphase I Metaphase II Homologous chromatids exchange corresponding segments. Sister chromatids remain joined at their centromeres. Prophase I of meiosis Duplicated pair of homologous chromosomes Chiasma, site of crossing over Spindle microtubule

Fig Metaphase I Metaphase II Recombinant chromosomes Gametes Recombinant chromosomes combine genetic information from different parents. Homologous chromatids exchange corresponding segments. Sister chromatids remain joined at their centromeres. Prophase I of meiosis Duplicated pair of homologous chromosomes Chiasma, site of crossing over Spindle microtubule

Fig LM

Fig Meiosis I Nondisjunction: Pair of homologous chromosomes fails to separate. NONDISJUNCTION IN MEIOSIS I NONDISJUNCTION IN MEIOSIS II

Fig Meiosis I Nondisjunction: Pair of homologous chromosomes fails to separate. NONDISJUNCTION IN MEIOSIS I Meiosis II Nondisjunction: Pair of sister chromatids fails to separate. NONDISJUNCTION IN MEIOSIS II

Fig Meiosis I Abnormal gametes Gametes Nondisjunction: Pair of homologous chromosomes fails to separate. NONDISJUNCTION IN MEIOSIS I Number of chromosomes Meiosis II Nondisjunction: Pair of sister chromatids fails to separate. Abnormal gametes Normal gametes n n n  1 n – 1 n  1 NONDISJUNCTION IN MEIOSIS II n – 1

Fig Abnormal egg cell with extra chromosome Normal sperm cell n  1 n (normal) Abnormal zygote with extra chromosome 2n  1

Fig Chromosome 21 LM

Fig. 8-22a Chromosome 21

Fig. 8-22b

Fig Age of mother Infants with Down syndrome (per 1,000 births)

Fig. 8-24

Fig. 8-T01

Fig. 8-UN01 Duplication of all chromosomes Genetically identical daughter cells Distribution via mitosis

Fig. 8-UN02 Duplicated chromosome Chromosome (one long piece of DNA) Centromere Sister chromatids

Fig. 8-UN03 Interphase Cell growth and chromosome duplication G2G2 Mitotic (M) phase S phase DNA synthesis; chromosome duplication G1G1 Genetically identical “daughter” cells Cytokinesis (division of cytoplasm) Mitosis (division of nucleus)

Fig. 8-UN04 MITOSIS Male and female diploid adults (2n  46) MEIOSIS Sperm cell Human Life Cycle Key Haploid (n) Diploid (2n) Haploid gametes (n  23) Egg cell Diploid zygote (2n  46) and development FERTILIZATION 2n2n n n

Fig. 8-UN05 Daughter cells Parent cell (2n) MITOSIS Chromosome duplication 2n2n2n2n MEIOSIS MEIOSIS I Parent cell (2n) Chromosome duplication Daughter cells n MEIOSIS II Pairing of homologous chromosome Crossing over n nn

Fig. 8-UN06 (a) LM (b) (c) (d)