ecosystems

• What is the palisade layer in a leaf?

  A layer of tightly packed cells with chloroplasts
• Why is the palisade layer important for photosynthesis?

  It ensures almost all light is absorbed
• What are stomata?

  Open pores for gas exchange
• How do stomata help during low water conditions?

  They can close to conserve water
• What is the function of spongy mesophyll in a leaf?

  It allows gases to diffuse in and around the leaf
• What is the waxy cuticle?

  The waterproof top layer of the leaf
• What is the purpose of the waxy cuticle?

  It prevents water from escaping
• How does temperature affect the rate of photosynthesis?

  Increasing temperature increases the rate
• What happens to enzymes at temperatures above 45°C?

  They begin to denature and stop working
• What is the effect of high chlorophyll concentration on photosynthesis?

  It results in a high rate of photosynthesis
• How does increasing carbon dioxide concentration affect photosynthesis?

  It increases the rate because it's a reactant
• What happens when carbon dioxide concentration exceeds a certain threshold?

  Further increases do not raise the rate
• How does light intensity affect the rate of photosynthesis?

  Increasing light intensity increases the rate
• What occurs if light intensity is increased beyond a certain threshold?

  The rate of photosynthesis will not increase
• What are the main factors affecting the rate of photosynthesis?

  • Temperature
  • Carbon dioxide concentration
  • Chlorophyll concentration
  • Light intensity
• What are the two different forms of respiration?

  Aerobic and anaerobic
• What is aerobic respiration?

  It uses oxygen to release energy
• What is anaerobic respiration?

  It does not use oxygen for energy release
• How can anaerobic respiration be exploited in food production?

  For making bread or alcohol
• What is the equation for aerobic respiration?

  Oxygen + glucose → water + carbon dioxide
• When do living things respire anaerobically?

  When there is limited oxygen available
• What is the equation for anaerobic respiration in animals?

  Glucose → lactic acid
• Why do you continue to breathe heavily after strenuous activity?

  To break down lactic acid
• What is meant by "repaying your oxygen debt"?

  It refers to the need for oxygen to break down lactic acid
• How does an increase in breath volume affect gas exchange?

  It increases the rate of gas exchange
• What happens to gas exchange when breathing rate increases?

  More oxygen is taken in and more carbon dioxide is released
• What are the key differences between aerobic and anaerobic respiration?

  • Aerobic respiration uses oxygen; anaerobic does not.
  • Aerobic produces more energy than anaerobic.
  • Anaerobic respiration results in lactic acid in animals.
• How does the body respond to increased energy demands during exercise?

  • Increases breathing rate
  • Increases breath volume
  • Enhances gas exchange in lungs