Plant structures and their functions

• What are auxins in plants?

  A group of plant hormones
• What is the role of auxins in plant growth?

  They inhibit root growth and stimulate shoot growth
• How are auxins used commercially?

  In rooting powders and selective weedkillers
• What is biomass?

  Total mass of organic material
• What does ethene do in plants?

  Stimulates ripening in fruit
• What are gibberellins?

  Plant hormones that regulate germination
• How can gibberellins be used commercially?

  To control flower and fruit formation
• What is gravitropism?

  A plant's growth response to gravity
• What are guard cells responsible for?

  Controlling the rate of transpiration
• How do guard cells regulate stomata?

  By changing shape based on water volume
• What does the inverse square law state about light intensity?

  It is inversely proportional to the square of the distance

  
• What is lignin's role in plants?

  Strengthens the walls of xylem cells
• What is a limiting factor in plant growth?

  A variable that limits the rate of a reaction
• What is the lower epidermis in a leaf?

  A layer containing stomata and guard cells
• What is negative plant tropism?

  Growth of a plant away from a stimulus
• What is the palisade mesophyll layer?

  Main photosynthetic tissue in plants
• Why does the palisade mesophyll layer contain many chloroplasts?

  It receives the most light for photosynthesis
• What is phloem's function in plants?

  Transport sugars from leaves to the plant
• What is photosynthesis?

  An endothermic reaction converting light energy
• What is the overall equation for photosynthesis?

  6CO₂ + 6H₂O ⟶ C₆H₁₂O₆ + 6O₂
• What is phototropism?

  A plant's growth response to light
• What is plant tropism?

  The growth response of a plant to a stimulus
• What is positive plant tropism?

  Growth of a plant towards a stimulus
• Who are producers in an ecosystem?

  Photosynthetic organisms at the food chain's start
• What are root hair cells specialized for?

  Uptake of water and minerals from soil
• What are rooting powders?

  Powder containing auxins for root growth
• What is the spongy mesophyll layer's function?

  Specialized for gas exchange in leaves
• What are stomata?

  Small holes for gas exchange in plants
• How do stomata control water loss?

  By opening or closing via guard cells
• What is translocation in plants?

  Movement of sugars via the phloem
• What is transpiration?

  Water loss from leaves via diffusion
• What factors affect the rate of transpiration?

  Light intensity, temperature, and air flow
• What is the upper epidermis in a leaf?

  A layer of transparent cells for light passage
• What is a vascular bundle?

  Part of the transport system in vascular plants
• What is the function of the waxy cuticle?

  Reduces water loss from leaf surfaces
• What is xylem's role in plants?

  Transport water and dissolved minerals
• How does xylem transport water?

  From roots to leaves of the plant