BIOLOGY (CETS)

• Balogy


  Study of living things
• Branches of biology

  • Zoology - study of animals
  • Botany - study of plants
  • Ecology - study of relationships between living things and their environment
  • Embryology - study of development in early stages of life
  • Anatomy - study of body structures
  • Physiology - study of body functions
  • Genetics - study of heredity
  • Cytology - study of cells
  • Microbiology - study of bacteria and unicellular organisms
• Cell


  Fundamental unit of life
• Prokaryotic cell


  • Has no membrane-bound nucleus
  • DNA is not enclosed in a nuclear membrane
  • Simpler in structure than eukaryotic cells
• Eukaryotic cell


  • Has a membrane-bound nucleus
  • DNA is enclosed in a nuclear membrane
  • More complex structure than prokaryotic cells
• Nucleus

  The control centre of the cell, enclosed in a semi-permeable nuclear membrane, containing the cell's genetic material (DNA)
• Ribosomes


  Organelles that synthesize proteins, receiving instructions from DNA and RNA
• Endoplasmic reticulum (ER)


  An interconnected network of tubes and sacs that transport materials within the cell
• Rough ER


  ER studded with ribosomes, involved in the production of proteins
• Smooth ER


  ER without ribosomes, involved in the production of lipids
• Golgi apparatus


  The packaging and distribution centre of the cell, modifying, sorting and packaging materials produced in the ER
• Vesicles


  Small membrane-bound sacs that transport materials within the cell
• Endocytosis


  The process by which a cell takes in material from outside by engulfing it in a vesicle
• Exocytosis


  The process by which a cell secretes material to the outside by fusing a vesicle with the cell membrane
• Lysosomes


  Organelles containing digestive enzymes that break down waste materials and pathogens
• Autophagy


  The process by which a cell breaks down and recycles its own components
• Peroxisomes


  Organelles that contain enzymes to break down toxic substances and produce hydrogen peroxide
• Mitochondria


  The 'powerhouses' of the cell, where ATP is produced through cellular respiration
• Chloroplasts


  Organelles found in plant cells that contain chlorophyll and are the site of photosynthesis
• Cell membrane


  The selectively permeable barrier that surrounds the cell and controls what goes in and out
• Vacuoles


  Membrane-bound sacs that store water, waste products, and other materials
• Cytoskeleton


  The network of protein filaments and tubules that give the cell its shape and allow for movement of organelles
• Microfilaments


  Thin protein filaments made of actin that provide structure and allow for cell movement
• Intermediate filaments


  Rope-like protein filaments that provide mechanical support and anchoring for the cell
• Cell junctions


  Connections between adjacent cells that allow for communication and transport
• Plasmodesmata


  Channels that connect the cytoplasm of adjacent plant cells, allowing the passage of materials between them
• Tight junctions


  Seal the space between animal cells, preventing leakage of materials
• Gap junctions


  Allow direct communication between the cytoplasm of adjacent animal cells
• Desmosomes

  Anchoring junctions that mechanical connect adjacent animal cell
• Passive transport


  The movement of substances down their concentration gradient without the use of energy
• Diffusion


  The movement of substances from an area of high concentration to an area of low concentration
• Osmosis


  The movement of water across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration
• Active transport


  The movement of substances against their concentration gradient, requiring the use of energy
• Bulk transport


  The movement of large materials in membrane-bound vesicles
• Cell cycle


  The series of events a cell goes through as it grows and divides
• Interphase


  The period of the cell cycle when the cell is actively growing and preparing for cell division
• Mitosis


  The process of cell division that produces two genetically identical daughter cells
• Stages of mitosis


  1. Prophase

  2. Prometaphase

  3. Metaphase

  4. Anaphase

  5. Telophase

  6. Cytokinesis
• Meiosis


  The process of cell division that produces four genetically distinct haploid daughter cells
• Stages of meiosis


  1. Meiosis I: Prophase I, Metaphase I, Anaphase I, Telophase I

  2. Meiosis II: Prophase II, Metaphase II, Anaphase II, Telophase II