Finding prokaryotic genes and non intronic eukaryotic genes Lecture 8 Global Sequence1.
Genes are in Nucleus of Eukaryotic Cells
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Transcript of Genes are in Nucleus of Eukaryotic Cells
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Genes are in Nucleus of Eukaryotic Cells
1930s
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Concluded: Genes are on Chromosomes
Prokaryotes: Circular chromosomes, Binary Fission
Eukaryotes: Linear chromosomes, Mitosis and Meiosis
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Chromosome Number
Field Horsetail
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Drosophila melanogaster Chromosomes
Diploid (2n = 8), 4 distinct chromosomes
3 autosomes, one pair of sex chromosomes (X & Y)
female male
polytene chromosomes
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Rice Chromosomes
Oryza sativa 2n = 24; 12 pairs of chromosomes
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Human Chromosomes22 pairs of autosomes, one pair of sex chromosomes (X & Y)
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Descriptions of Eukaryotic Chromosomes
Unreplicated (G1) and Replicated (G2)
one chromatid two sister chromatids per chromosome per chromosome
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Descriptions of Eukaryotic Chromosomes
All unreplicated chromosomes pictured
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Descriptions of Eukaryotic Chromosomes
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Eukaryotic Cell Cycle
Eukaryotes: Linear Chromosomes, Mitosis and Meiosis
Replicated Unreplicated
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Mitosis - growth and healing
Interphase
Prophase - Chromosomes condense
Metaphase Chromosomes align independently
Anaphase Sister chromatids segregate
TelophaseCytokinesis
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Mitosis - Prophase
A A
a ab b
BB
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Mitosis - Metaphase & Anaphase
A A
a a
b b
BB
A A
a a
b b
B B
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Mitosis - Telophase
A A
a a
b b
B B
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Highlights of Mitosis
Diploid cellReplicated chromosomes
Diploid cellsUnreplicated chromosomes
A A a a b bBB
A
ab
B
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Cytokinesis
Cell furrow Cell plate
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Meiosis - Formation of Haploid Gametes
Diploid cell (one)Replicated chromosomes
Haploid cells (four)Unreplicated chromosomes
A A a a b bBB
A
a
b
B
A
b a B
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Highlights of Meiosis
1. Chromosomes replicate once, cell divides twice
2. Homologous chromosomes pair then segregate
3. Chromosome number is reduced - diploid to haploid
4. Each gamete receives one of each type of chromosomewith one copy of each type of gene
OR
A
a b
B
a
A b
B
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Stages of Meiosis I - Prophase
Leptonema - chromosomes condense
Zygonema - homologous chromosomes pair
Pachynema - Tetrads easily seen, crossing over occurs
Diplonema - Chiasma easily seen
Diakinesis - Terminalization, chiasmata resolved
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Stages of Meiosis I - Prophase
Leptonema -chromosomes condense
Zygonema - homologous chromosomes pair
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Stages of Meiosis I - Prophase
Pachynema - tetrads easily seen, crossing over occurs
Diplonema - chiasma easily seen
Diakinesis - terminalization, chiasmata resolved
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Meiosis I
Diploid to Haploid
Reductional Division
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Meiosis II
Haploid cell with replicated chromosomesto
Haploid cells with unreplicated chromosomes
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Meiosis I & II
Figure 12.9
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Compare and Contrast: Mitosis & Meiosis
Griffith et al. Introduction to Genetic Analysis.
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Mitosis vs. Meiosis
Figure 12.11
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Spermatogenesis vs. Oogenesis
Figure 12.13
In testis
continuousproduction
In ovaries
In 3 monthsfetus, allin Meiosis Iprophase
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Gametogenesis in Plants
Figure 12.15.