GCSE Biology higher tier double award

• Eukaryotic cells


  Consist of plant cells and animal cells
• Prokaryotic cells


  Bacterial cells
• Magnification


  Image size / Actual size
• Advantages and disadvantages of microscopes

  • Light microscopes: Easy to use, cheap
  • Electron microscopes: Better magnification and resolution
• Stem cells


  Undifferentiated cells with potential to transform into specialized cells
• Specialized cells


  Nerve cells, sperm cells, egg cells, brain cells, muscle cells
• Mitosis


  One cell dividing into two identical daughter cells
• Diffusion


  Movement from high to low concentration
• Osmosis

  Movement from high to low concentration
• Active transport

  Movement from low to high concentration
• Cells, tissues, organs, organ systems

  Hierarchical organization of living things
• Lock and key model

  Describes how enzymes work
• Enzymes in the digestive system

  • Protease
  • Carbohydrase
  • Lipase
• Digestive system

  1. Mouth

  2. Esophagus

  3. Stomach

  4. Small intestine

  5. Large intestine

  6. Rectum
• Circulatory system

  Heart with 4 chambers, arteries, veins, capillaries
• Xylem

  Transports water from roots to plant
• Phloem

  Transports food up and down the plant
• Communicable disease

  Disease that can be spread between people
• Pathogen types

  • Bacteria
  • Protists
  • Fungi
  • Viruses
• Disease prevention methods

  • Hygiene
  • Self-isolation
  • Vaccination
• Lines of defense against disease

  1. Physical barriers (skin, mucus, stomach acid)

  2. Phagocytosis by white blood cells

  3. Antibodies and memory cells produced by lymphocytes
• Photosynthesis

  Process where plants use light energy, carbon dioxide and water to produce glucose and oxygen
• Respiration

  Process where organisms use glucose and oxygen to produce carbon dioxide and water, releasing energy
• Limiting factors


  Factors that limit the rate of photosynthesis (e.g. light, temperature, carbon dioxide, water, chlorophyll)
• Aerobic respiration


  Respiration that requires oxygen
• Anaerobic respiration


  Respiration that does not require oxygen
• Oxygen debt

  Oxygen required to be repaid after anaerobic respiration
• Circulatory system

  An example of an organ system, its role is to transport oxygen and nutrients to the body's tissues
• Circulatory system

  • Relies on 3 main things: blood, blood vessels, heart
• Blood flow through the circulatory system

  1. Blood flows from heart to lungs, gains oxygen, flows back to heart

  2. Oxygenated blood flows from heart to body, gives up oxygen, flows back to heart
• Heart


  Consists of 4 chambers with thick muscular walls, veins and arteries
• Atria


  Top chambers of the heart
• Ventricles


  Bottom chambers of the heart
• Valves


  Prevent blood from flowing backwards, ensure blood flows in the right direction
• Blood flow through the heart

  1. Flows into right atrium and left atrium

  2. Atria contract, push blood into ventricles

  3. Ventricles contract, push blood into pulmonary artery and aorta

  4. Atria refill with new blood, cycle repeats
• Artificial pacemaker

  Small device implanted under the skin above the heart, with a wire that carries electrical current to the heart
• Artery

  Any vessel that carries blood away from the heart
• Vein

  Any vessel that carries blood to the heart
• Arteries don't always carry oxygenated blood, and veins don't always carry deoxygenated blood
• Coronary arteries

  Small arteries that branch off the aorta and encircle the heart to supply it with oxygenated blood