cell reproduction i. introduction a. history. 1. r. r. brown, 1840’s, existence of the nucleus or...
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Cell Reproduction
I. Introduction
A. History
1. R. Brown, 1840’s, existence of the nucleus or “brain of the cell”
2. W. Fleming 1860’s dark staining threads appeared to “dance”
3. A. Weismann in 1887 proposed meiosis for sex cells
outlined the steps of mitosis
II. StrategiesA.
Prokaryotes
Prokaryotes reproduce by1. Binary
fissionor by
2. Endospore formation
Figure 17.11
Figure 17.11
B. Eukaryotes1.
Asexual
1. Asexual methods are for replacing cells by mitosis
a. Animals do fission, budding, and/or fragmenting
Advantage
Fission Budding
Figure 46.1
Fragmenting
Figure 8.1
1. Asexual methods replace cells by mitosis
b. Plants do runners, spore formation, or buddingc. Fungi do budding or spore formationd. Protistans are just weird
2. Sexual
2. Sexual = similar yet variation meiosisa. Plants do alternation of generations sporophyte and a gametophyte generation.
Figure 18.3
b. Fungi same strategy as plantsc. Protists again weird
d. Animals male and female interactions but variances are parthenogenesis, hermaphroditic, sequential hermaphroditic (protogynous = female first or protandrous = male first)
hermaphroditic
Sequential Hermaphroditic = Protogynous vs. Protandrous
d. Animals male and female interactions, but variances are monoecious, dioecious, monogamy, polygamy, and others.
Monoecious
Dioecious
Monogamy
Polygamy
III. Cell CycleA.
DefinitionB. Stages
The Cell Cycle
Figure 8.3
C. Controls1. External
External controls outside influenceWhat could be a signal?
Cell contact can inhibit cellular growth.
2. Internal
Internal controls == internal clock
Figure 8.9
Apoptosis = programmed cell death
Figure 8.11
D. Cancer
Cancer == benign, malignant, or metastaticFigure
8.12
Figure 8.13
Figure 8.14
IV. MitosisA. DefinitionB. Phases
Mitosis == prophase, metaphase, anaphase, and telophase plus interphase
Figure 8.5
Prophase = condense chromatids, dismantle nuclear membrane, and start to build spindle
Metaphase = attach chromatids to spindle fibers via centromere and line up chromatids across equatorAnaphase = move chromatids toward poles
Telophase = reverse steps of ProphaseInterphase = time between mitotic divisions and does G1, S, and G2 of cycle
V. CytokinesisA.
DefinitionB. Strategies
Plants
Animals
Figure 8.8
Figure 8.7
VI. MeiosisA. DefinitionB. Phases
Figure 9.6
Figure 9.7
VII. Comparison
Figure 9.8
VIII. Variation from MeiosisA. Independent
Assortment
Figure 10.8
Figure 10.8
B. Random Fertilization
C. Problems1. Whole Chromosomes
Figure 9.9
a. Non-disjunction is the failure of homologous pairs to separate in meiosis Ib. or sister chromatids to separate in
meiosis II.
2. Parts of Chromosomes
a. Anaphase of meiosis IDeletio
nsDuplications
Figure 13.3
Figure 13.4
Translocations
Inversions
Figure 13.5
Figure 13.6
Are these good or bad?
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