organising animals and plants

• What is the function of the vena cava?

  It carries blood from the body
• Which chamber of the heart receives blood from the body?

  Right atrium
• What chamber of the heart pumps blood to the lungs?

  Right ventricle
• Which chamber of the heart receives oxygenated blood from the lungs?

  Left atrium
• What is the function of the left ventricle?

  Pumps blood to the rest of the body
• What artery carries blood from the heart to the lungs?

  Pulmonary artery
• What artery carries blood from the heart to the rest of the body?

  Aorta
• What vein carries blood from the lungs to the heart?

  Pulmonary vein
• What are the main components of the human heart?

  • Right atrium
  • Right ventricle
  • Left atrium
  • Left ventricle
  • Aorta
  • Pulmonary artery
  • Pulmonary vein
  • Valves
• What are pacemaker cells and where are they found?

  They control heart rate and are found in the right atrium
• Why is the left ventricle wall thicker than the right ventricle wall?

  It pumps blood at a higher pressure throughout the body
• What is double circulation in the human heart?

  Blood passes through the heart twice for each circuit
• What are the characteristics of biological heart valves?

  • Do not damage red blood cells
  • Prone to hardening over years
  • May require replacement surgeries
• What are the four parts of blood?

  Red blood cells, white blood cells, plasma, platelets
• What is the function of red blood cells?

  They carry oxygen
• What is the role of white blood cells?

  They help fight infections
• What do platelets do?

  They help with blood clotting
• What is the function of plasma in blood?

  It carries proteins and other chemicals
• What are the characteristics of arteries?

  • Carry oxygenated blood away from the heart
  • High pressure blood flow
  • Strong and elastic walls
  • Thick muscular walls with narrow lumen
• What are the characteristics of capillaries?

  • Extremely narrow for single file blood flow
  • Supply food and oxygen to cells
  • Take away waste products like CO₂
  • Thin walls for short diffusion pathway
  • Permeable walls for easy substance exchange
• What do veins carry?

  Deoxygenated blood to the heart
• Why do veins have thinner walls than arteries?

  They carry blood at lower pressure
• What is the function of valves in veins?

  To keep blood flowing in the right direction
• What is the rate of blood flow?

  Volume of blood per number of minutes
• What is the trachea's function?

  It carries air to the bronchi
• What do bronchi do?

  They branch from the trachea
• What are bronchioles?

  They are smaller branches of bronchi
• What are alveoli?

  Small air sacs where gas exchange occurs
• What is transpiration in plants?

  • Movement of water/minerals from roots to leaves
  • Water evaporates from leaves and diffuses out
  • Creates a continuous flow of water in xylem
• What factors affect the rate of transpiration?

  • Light: More light = faster transpiration
  • Temperature: Higher temperature = faster transpiration
  • Wind: Windy conditions = faster transpiration
  • Humidity: Higher humidity = slower transpiration
• How do guard cells regulate transpiration?

  They control the opening and closing of stomata
• What happens to guard cells when they are turgid?

  They curve and open the stoma
• What happens to guard cells when they are flaccid?

  They shrink and close the stoma
• What is translocation in plants?

  • Movement of dissolved substances (sugars)
  • Transported through phloem tissues
  • For use or storage in the plant
• What is the role of xylem in plants?

  Transport water and minerals from roots
• What is the role of phloem in plants?

  Transport dissolved sugars from leaves
• What is transpiration stream?

  • Water moves up against gravity
  • Through tubes made of dead xylem cells
  • Evaporation from leaves creates a flow
• How does transpiration affect water uptake?

  • Faster transpiration increases water uptake
  • Slower transpiration helps plants survive drought
  • Regulated by guard cells and stomata
• What is the relationship between transpiration and photosynthesis?

  • More light increases photosynthesis
  • Stomata open wider for CO₂ intake
  • Faster transpiration occurs with more light
• What happens if water loss is faster than replacement?

  • Plants can wilt
  • Stomata may close to reduce loss
  • Guard cells regulate this process