Cell Reproduction I. Introduction A. History 1. R. Brown, 1840’s, existence of the nucleus or “brain of the cell”. 2. W. Flemming 1860’s dark staining threads appeared to “dance”. outlined the steps of mitosis 3. A. Weismann & Eduard Strasburger in 1887 proposed meiosis for sex cells.

II. Strategies A. Prokaryotes reproduce by 1. Binary fission or by 2. Endospore formation Figure 17.11

B. Eukaryotes 1. Asexual methods Why? Advantage vs. Disadvantage a. Animals do i. Fission ii. Budding Figure 29.1

and/or iii. Fragmenting Figure 8.1

b. Plants do runners, spore formation, or budding c. Fungi do budding or spore formation d. Protistans are just weird.

2. Sexual similar yet variation via meiosis Advantage vs. Disadvantage a. Plants do alternation of generations  sporophyte and a gametophyte generation. Figure 18.3

b. Fungi similar strategy as plants c. Protists again weird d. Animals male and female interactions but variances are i. Parthenogenesis,

ii. Hermaphrodite simultaneous, or sequential hermaphrodite (Protogynous vs. Protandrous).

iii. Monoecious vs. Dioecious,

iv. Monogamy vs. Polygamy.

III. Cell Cycle A. Definition B. Stages Figure 8.3

C. Controls 1. External = outside influences What could be a signal? a. Hormones? b. Cell contact can inhibit cellular growth. c. Environmental cues.

2. Internal = a. Biological clocks Figure 8.9

b. Apoptosis = programmed cell death Figure 8.10

D. Cancer 1. Classification a. benign b. malignant c. metastatic Figure 8.15

2. Prevention Figure 8.16 Figure 8.14

IV. Mitosis A. Definition B. Phases Mitosis  Prophase, Metaphase, Anaphase, and Telophase plus Interphase Figure 8.5

2. Prophase = condense chromatids, dismantle nuclear membrane, and start to build spindle 3. Metaphase = attach chromatids to spindle fibers via centromere and line up chromatids across equator 4. Anaphase = move chromatids toward poles 5. Telophase = reverse steps of Prophase 1. Interphase = time between mitotic divisions and does G1, S, and G2 of cycle

V. Cytokinesis A. Definition B. Strategies 2. Animals 1. Plants Why? Figure 8.7 Figure 8.8

VI. Meiosis B. Phases A. Definition Figure 9.5

VII. Comparison Figure 9.6

VIII. Variation from Meiosis A. Independent Assortment Figure 10.8 B. Random Fertilization C. Crossing Over

IX. Problems A. Whole Chromosomes 1. Non-disjunction I is the failure of homologous pairs to separate in Anaphase I of meiosis I 2. Non-disjunction II or sister chromatids to separate in Anaphase II of meiosis II. Figure 9.7

B. Parts of Chromosomes 1. Occur when? 2. Types b. Duplications a. Deletions b. Duplications Figure 13.3 Figure 13.4

3. Are these good or bad? c. Translocations d. Inversions Figure 13.5