Mitosis

Cellular Reproduction and the Cell Cycle

What do all cells require to survive? ,[object Object],– produce required molecules – direct life processes ,[object Object],[object Object]

Why do cells divide? ,[object Object],[object Object],[object Object]

Cell Cycle ,[object Object],[object Object],– Cell grows, adding more cytoplasmic constituents – DNA is replicated – cell divides into two identical daughter cells

Essential Feature of Cell Division ,[object Object]

Two Fundamental Types of Cells (organisms): ,[object Object],[object Object]

Prokaryotic Cell ,[object Object],[object Object],[object Object],[object Object],[object Object]

Eukaryotic Cell ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

During non-division phase of cell cycle ,[object Object],[object Object],– cell can only use DNA to produce molecules when in extended state

– easier to sort and organize DNA into daughter cells During division phase of cell cycle ,[object Object],[object Object],– each chromosome is a single molecule of DNA

Prokaryotic Cell Cycle ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Cell wall Plasma membrane Chromosome

[object Object],[object Object],[object Object],What is Mitotic Cell Division? ,[object Object],[object Object],[object Object],=> Maintains chromosome ploidy of cell

Ploidy – refers to the number of pairs of chromosomes in cells ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Each species has a characteristic number of chromosomes: Prokaryotes – one chromosome Crayfish – 200 chromosomes Human – 46 chromosomes => 23 pairs of chromosomes

Diploid organisms receive one chromosome from female parent (= maternal ) and one chromosome from male parent (= paternal ) A “matched” pair of maternal and paternal chromosomes are called homologues

Structure of a eukaryotic chromosome ,[object Object],Chromatid Chromatid centromere

[object Object],[object Object],[object Object],duplicated chromosome ,[object Object],[object Object],[object Object]

daughter chromosomes sister chromatids

Eukaryotic Cell Cycle ,[object Object],[object Object],[object Object],[object Object],[object Object]

Interphase ,[object Object],[object Object],G 1 – cell grows in size – organelles replicated - majority of cell life span (90%) in this stage S – replication of DNA – synthesis of proteins associated with DNA

G 2 – synthesis of proteins associated with mitosis

Simplified cell cycle G 1 G 2 S Mitotic Cell Division

Mitotic Cell Division ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Mitosis 4 phases: 1 st – Prophase (3 major events) 2 nd – Metaphase 3 rd – Anaphase 4 th – Telophase and Cytokinesis

Prophase i) chromosomes condense ,[object Object],ii) spindle fibers form iii) chromosomes are captured by spindle

Chromosomes Condense ,[object Object],[object Object],[object Object],[object Object],[object Object]

Mitotic Spindle Forms ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

[object Object],[object Object],[object Object]

Spindle Captures Chromosomes ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

sister chromatid sister chromatid centromere spindle fiber kinetochores centriole aster fibers

[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

chromatin nucleolus nucleus centrioles condensing chromosomes

Metaphase ,[object Object],[object Object],[object Object],centrioles spindle fibers chromosomes

Anaphase ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

free spindle fibers V-shaped chromatid

Telophase ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

[object Object],[object Object],chromosomes decondensing nuclear envelope reforming nucleolus reappears pinching of cell membrane at equator

Cytokinesis ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Mitotic Cell Division Functions: ,[object Object],[object Object],[object Object],[object Object]

Summary of Mitosis ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Cancer ,[object Object],[object Object],[object Object],[object Object]

Cancer Progression ,[object Object],[object Object],[object Object]

G2 Phase Production of mitosis proteins The Cell Cycle

Mitosis animation http://www.sci.sdsu.edu/multimedia/mitosis/mitosis_qt1.html

Mitosis

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Mitosis