Topic 1: Cell Biology:

• What is the main function of the cell wall in both animal and plant cells?

  Outer protection
• Where do reactions occur in a cell?

  In the cytoplasm
• What controls cell activities in eukaryotic cells?

  The nucleus
• What is the role of the cell membrane?

  It controls what enters and leaves the cell
• Where does respiration occur in a cell?

  In the mitochondria
• What is the function of chloroplasts in plant cells?

  Where photosynthesis takes place
• What is a vacuole in plant cells?

  A large permanent sac
• What is the main component of a bacterial cell?

  Cytoplasm
• What is the shape of the DNA in bacterial cells?

  A ring of genetic material
• What is a plasmid in bacterial cells?

  A small loop of DNA
• What is the role of ribosomes in bacterial cells?

  They make proteins
• What is the formula for magnification?

  Magnification = image size / actual size
• How do microscopes help us?

  They increase the image size to see small things
• What is binary fission?

  A simple cell division process bacteria use to reproduce
• What happens during binary fission?

  The DNA replicates and the cell divides into two identical daughter cells
• What is the cell cycle?

  The sequence of events that takes place before a cell divides
• What must happen before a cell divides?

  It needs to copy its genetic material (DNA)
• What are the phases of the cell cycle?

  1. Growth - increase in size and number of organelles
  2. DNA replication - the DNA replicates
  3. Division - cell divides
• What are stem cells?

  Cells that can differentiate into specialized cells
• What is active transport?

  The movement against the concentration gradient
• Why do multicellular organisms need exchange surfaces and transport systems?

  To meet the needs of every cell
• Where can stem cells be harvested from?

  From the umbilical cord
• What are the four characteristics of exchange surfaces in single-celled organisms?

  1. Large surface area
  2. Thin membrane
  3. Efficient blood supply (in animals)
  4. Ventilation (in gas exchange in animals)
• What are the four organs adapted for exchange?

  1. Leaves - gas exchange
  2. Gills - gas exchange in fish
  3. Small intestine - absorption of food molecules
  4. Alveoli in lungs - gas exchange
• How do leaves facilitate gas exchange?

  They have a flat shape and stomata
• How do gills facilitate gas exchange in fish?

  Oxygen and carbon dioxide move between water and blood
• What is the structure of the small intestine for absorption?

  It has a single layer of surface cells and villi
• How do alveoli facilitate gas exchange?

  They have thin walls and a capillary network
• What is osmosis?

  The movement of water molecules across a partially permeable membrane
• In which direction do water molecules move during osmosis?

  From a region of higher water concentration to a region of lower water concentration
• What type of membrane is involved in osmosis?

  A partially permeable membrane
• What are the key components of osmosis?

  • Movement of water molecules
  • Across a partially permeable membrane
  • From higher water concentration to lower water concentration
• What is the net movement of water molecules in osmosis?

  The net movement is from higher water concentration to lower water concentration
• What is the relationship between water concentration and sucrose solution in osmosis?

  Water moves from a region of higher water concentration to a sucrose solution with lower water concentration