cellular reproduction

• cell division

  • process by which cells duplicate their contents and then divide reproduction
• karyokinesis

  • division of nucleus
• cytokinesis

  • division of cytoplasm
• MITOSIS

  • type of cell division that produces two identical cells
  • has 4 stages
• PROPHASE

  • spindle fibers appear
  • asters start to form around centrioles
  • LONGEST STAGE IN MITOSIS
• METAPHASE

  • centrioles have moved toward the poles
  • chromosomes line up along the equatorial plate
  • each chromosome is attached to a spindle fiber at the centromere
• ANAPHASE

  • shortest stage
  • each chromosome splits
  • cytokinesis begins
• TELOPHASE

  • spindle fibers disappear
  • chromosomes uncoil or unfold
• CYTOKINESIS

  • final phase of cell division
  • cytoplasm divides forming two identical cells
• MEIOSIS - process wherein a diploid parent produces 4 unique haploid cells

  • it reduces the number of chromosomes
  • produces sex cells or germ cells or gametes
• MEIOSIS: a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores
• PROPHASE 1 - chromosomes duplicate

  • crossing over occurs
  • longest and most complex
• METAPHASE 1 - nuclear membrane and nucleolus disappear

  • produces spindle fiber
  • the chromosomes align
• ANAPHASE 1

  • chromosomes seprate and move to opposite poles
• TELOPHASE 1

  • chromosomes reach the poles
• PROPHASE 2

  • chromatids condense and become visible
  • centrioles are doubled
  • DNA does not replicate
• METAPHASE 2

  • chromosomes align at the equator
• ANAPHASE 2

  • centromeres divide
  • a cleavage furrow is produced
• TELOPHASE 2

  • chromosomes reach the poles
  • a new nuclear membrane forms
  • 4 haploid daughter cells are formed
• gametogenesis - process by which gametes or reproductive cells are formed
• spermatogenesis - production of sperm cells in the testes
• oogenesis - production of egg cells in the ovary
• both sperm and egg cells originally come from cells with 46 chromosomes, and becomes 23 chromosomes
• MEIOSIS 1

  A) METAPHASE 1

  B) PROPHASE 1

  C) ANAPHASE 1

  D) TELOPHASE 1