Prokaryotic cell reproduction Binary Fission Eukaryotic Cell Cycle
Prokaryotic cell reproduction Binary Fission
Eukaryotic Cell Cycle
Eukaryotic Cell Reproduction: Mitosis & Meiosis Mitosis: cell reproduction for growth and replacement of cells. This makes identical copies (clones) Meiosis: cell reproduction for the production of gametes, such as egg and sperm (sex cells) How many chromosomes in a human cell such as a skin cell? How many chromosomes in egg and sperm?
Human Karyotype Is this person male or female?
46 chromosomes replication 46 chromatids 46 chromosomes Mitosis One division 23 Meiosis Two divisions 23 23 chromosomes 23
Mitosis: cell reproduction for growth and replacement of cells. This makes identical copies (clones) What are some examples of mitosis in the body? • Cuts and scrapes • Embryonic growth • Aging • Stomach cells What are some examples of mitosis in other organisms? • Asexual reproduction (budding and fragmentation) • Plants: growth of roots and stems • Regeneration (starfish arm, lizard tail)
46 chromosomes replication 46 chromatids 46 chromosomes Mitosis One division 23 Meiosis Two divisions 23 23 chromosomes 23
Sister Chromatids centromere DNA Replication Chromosome Sister Chromatids
Phases in Mitosis • Interphase: DNA replication • Prophase: chromosomes thicken, nucleus disappears • Metaphase: chromosomes line up at center • Anaphase: centromeres split, sister chromatids separate • Telophase: cytokinesis, division of the cytoplasm
Applications of Mitosis? Cancer = abnormal growth of cells
Control of the Cell Cycle MPF is a protein that triggers mitosis. Where is MPF in high amounts and in low amounts?
Regulation of Cell Cycle • What controls cell reproduction? • MPF = Maturation Promoting Factor MPF = cyclin + cdk (cdc 2) Protein Kinase = activates other proteins i. e. spindle fibers that move chromosomes • Two functions of MPF: 1. triggers mitosis 2. activates enzymes to breakdown cyclin (negative feedback)
Cancer • Transformation = process that converts a normal cell to a cancer cell • Tumor = loss of cell cycle control = abnormal growth of cells • Benign = noncancerous, Malignant = cancerous • Metastasis = spread rate of a malignant cancer to locations other than their origin (tumor cells enter blood vessels and travel to other parts of the body)
Meiosis: cell reproduction for the production of gametes, such as egg and sperm (sex cells) • Meiosis cuts the number of chromosomes in half • Meiosis occurs in gonads • Gonads are reproductive organs (such as ovaries and testes) • 2 divisions 1 st Meiotic division Interphase Prophase I Metaphase I Anaphase I Telophase I 2 nd Meiotic division Prophase II Metaphase II Anaphase II Telophase II
Homologous Pair (Homologous Chromosomes) • Chromosomes that carry genes in the same place for the same traits • One is maternal in origin (from the egg) • The other is paternal in origin (from the sperm) Hair color Eye color Skin tone hitchikers earlobes widow’s
1 st Meiotic Division • • Interphase: DNA replication Prophase I: crossing over Metaphase I: independent assortment Anaphase I: homologous pairs separate, centromeres intact • Telophase I: cytokinesis
2 nd Meiotic Division • Prophase II: reorganization, no crossing over • Metaphase II: chromosomes line up with centromere on line • Anaphase II: centromere splits, sister chromatids separate • Telophase II: cytokinesis
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