2022 paper 1

• What is the function of the nucleus in a cell?

  • Contains genetic information
  • Controls cell activities
• What is the role of mitochondria in a cell?

  • Site of aerobic respiration
  • Provides energy for the cell
• How does the cell membrane function?

  • Controls movement of substances
  • Regulates entry and exit of materials
• What is the purpose of a control variable in an experiment?

  • Kept constant during experiments
  • Ensures only independent variable is tested
• Define active transport and how it differs from diffusion.

  • Active transport: moves substances against gradient
  • Requires energy; diffusion is passive
• What is the role of enzymes in the digestive system?

  • Break down large food molecules
  • Convert them into smaller, soluble ones
• Describe the structure and function of the human heart.

  • Four chambers
  • Pumps blood, supplies oxygen and nutrients
  • Removes waste from the body
• How does the structure of arteries differ from veins?

  • Arteries: thick, elastic walls for high pressure
  • Veins: thinner walls, valves to prevent backflow
• What is the function of red blood cells?

  • Transport oxygen from lungs to tissues
• How do vaccines protect against diseases?

  • Stimulate immune system
  • Produce antibodies for immunity
• What is the difference between bacterial and viral infections?

  • Bacterial: caused by bacteria, treated with antibiotics
  • Viral: caused by viruses, not treated with antibiotics
• How do white blood cells defend against pathogens?

  • Ingest pathogens
  • Produce antibodies and release antitoxins
• What is herd immunity?

  • Large portion of community immune
  • Reduces disease spread
• What is the word equation for photosynthesis?

  • Carbon dioxide + water → glucose + oxygen
• How does light intensity affect the rate of photosynthesis?

  • Rate increases with light intensity
  • Until another factor becomes limiting
• What is anaerobic respiration and how does it differ from aerobic respiration?

  • Anaerobic: occurs without oxygen, less energy
  • Aerobic: uses oxygen, produces more energy
• How does exercise affect respiration?

  • Increases energy demand
  • Leads to increased respiration rate
• What is the function of the cell membrane?

  Controls movement of substances in and out
• What is the function of the cytoplasm?

  Where most chemical reactions take place
• What is the function of the cell wall in plant cells?

  Provides structural support and protection
• What is the function of chloroplasts in plant cells?

  Site of photosynthesis converting light energy
• What is the function of the vacuole in plant cells?

  Maintains cell pressure and stores nutrients
• What is the function of the atria in the heart?

  Receive blood returning to the heart
• What is the function of the ventricles in the heart?

  Pump blood out of the heart
• What is the function of the coronary arteries?

  Supply oxygenated blood to the heart muscle
• What is the function of the lungs in the human body?

  Facilitate exchange of oxygen and carbon dioxide
• What is the function of the alveoli in the lungs?

  Gas exchange occurs; oxygen enters blood
• What is the function of white blood cells?

  Defend the body against pathogens
• What is the function of antibodies?

  Bind to antigens on pathogens, neutralizing
• What is the function of antitoxins?

  Neutralize toxins released by pathogens
• What is the function of memory cells in the immune system?

  Remember specific pathogens for faster response
• What is the balanced chemical equation for photosynthesis?

  6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
• What factors can limit the rate of photosynthesis?

  Light intensity, CO₂ concentration, temperature
• What is the word equation for aerobic respiration?

  Glucose + oxygen → carbon dioxide + water
• What is the word equation for anaerobic respiration in animals?

  Glucose → lactic acid + energy
• What is the function of mitochondria in cells?

  Site of aerobic respiration producing energy
• What are the functions of the cell membrane, cytoplasm, and cell wall?

  • Cell membrane: Controls movement of substances
  • Cytoplasm: Site of chemical reactions
  • Cell wall: Provides support and protection
• What are the functions of chloroplasts and vacuoles in plant cells?

  • Chloroplasts: Site of photosynthesis
  • Vacuoles: Maintain pressure and store substances
• What are the functions of the heart's atria and ventricles?

  • Atria: Receive blood returning to the heart
  • Ventricles: Pump blood out of the heart
• What are the functions of the coronary arteries and lungs?

  • Coronary arteries: Supply blood to heart muscle
  • Lungs: Facilitate gas exchange with blood