Plants and photosynthesis

• What is photosynthesis?

  A series of enzyme-controlled reactions
• What role does chlorophyll play in photosynthesis?

  It absorbs light energy for the reaction
• What is the organ of photosynthesis in plants?

  The leaf
• Why is water important for plants?

  It is used in photosynthesis and provides support
• How does water contribute to cell turgidity?

  It fills cell vacuoles, pushing against walls
• What happens to water from the xylem in leaves?

  It evaporates into air spaces
• What is transpiration?

  Loss of water vapor from the stoma
• What are limiting factors in photosynthesis?

  Factors that affect the rate of photosynthesis
• How is the rate of photosynthesis usually measured?

  By recording the volume of oxygen produced
• How can light intensity be investigated in photosynthesis?

  By moving a plant closer to a light source
• What happens to the rate of photosynthesis as temperature increases?

  It increases until a certain point
• What is the effect of increasing light intensity on photosynthesis?

  The rate of photosynthesis increases
• What is the purpose of testing a leaf for starch?

  To determine if photosynthesis has occurred
• What is the first step in testing a leaf for starch?

  Boil the leaf to kill it
• What is the purpose of decolourising the leaf with ethanol?

  To remove chlorophyll from the leaf
• What color indicates the presence of starch in a leaf test?

  Blue/black
• What minerals do plants need for healthy growth?

  Certain minerals like nitrates and phosphates
• What is the effect of nitrate deficiency in plants?

  Causes poor growth
• What growth problem is associated with potassium deficiency?

  Yellowing of leaves
• What is the effect of phosphate deficiency in plants?

  Causes poor root growth
• What factors affect the rate of transpiration?

  Temperature, humidity, and wind speed
• What is the role of xylem in plants?

  It carries water and minerals from roots
• How are minerals transported into the plant?

  They are actively transported into the roots
• What allows water to be drawn up by the xylem?

  Active transport of minerals into roots