Cell Division Overview

  • Asexual vs Sexual Reproduction: Key methods of reproduction in biology.
  • Gametes: Sex cells; include ova (egg) and sperm.
  • Cell Division Types:
    • Binary Fission: Method of asexual reproduction in bacteria; involves chromosome duplication and division into two cells.
    • Mitosis: Division process for somatic cells.
    • Meiosis: Division process for gamete formation.

Chromosome Structure and Number

  • Chromosome Types:
    • Diploid Cells (2n): Two sets of chromosomes (e.g., human somatic cells, n=46).
    • Haploid Cells (n): One set of chromosomes (e.g., gametes, n=23).
  • Chromosome States:
    • Unduplicated: Single chromosome.
    • Duplicated: Chromosome made of two sister chromatids.

Cell Cycle

  • Phases:
    • G1 Phase: Cell growth and functional activity.
    • S Phase: DNA replication occurs, each chromosome is duplicated.
    • G2 Phase: The cell checks for errors and prepares for mitosis.
  • Mitosis Stages:
    • Prophase: Chromatin condenses into visible chromosomes.
    • Prometaphase: Nuclear envelope breaks down, spindle fibers attach to kinetochores.
    • Metaphase: Chromosomes align at the metaphase plate.
    • Anaphase: Sister chromatids separate and move to opposite poles.
    • Telophase: Nuclear envelope reforms, followed by cytokinesis leading to two daughter cells.

Cytokinesis

  • Animal Cells: Form a cleavage furrow through a contractile ring.
  • Plant Cells: Form a cell plate which develops into a new cell wall.

Cancer Biology

  • Cancer Definition: Uncontrolled cell division leading to the formation of tumors.
  • Tumor Types:
    • Benign: Non-cancerous, localized growth.
    • Malignant: Cancerous, may metastasize to other body parts.
  • Key Terms:
    • Proto-oncogenes: Normal genes that can become oncogenes when mutated.
    • Tumor Suppressor Genes: Genes that regulate cell division and prevent tumor formation.
  • Additional Concepts: Angiogenesis, mutations, apoptosis.

Review Activities

  • Utilize resources such as video materials and PowerPoint presentations for a comprehensive review of cell division and cancer biology.