Plant Structure and Function

Roots

• Underground plant organs that absorb water and minerals from the soil
• Types of roots:
  • Taproot: single, large root that grows straight down (e.g. carrot)
  • Fibrous root: multiple, thin roots that spread out (e.g. grass)
• Functions:
  • Anchorage: hold the plant in place
  • Absorption: absorb water and minerals
  • Storage: store food and nutrients

Stems

• Above-ground plant organs that support leaves, flowers, and fruits
• Functions:
  • Support: hold up leaves, flowers, and fruits
  • Transport: transport water, minerals, and sugars between roots and leaves
  • Storage: store food and nutrients
• Types of stems:
  • Herbaceous: non-woody, soft stems (e.g. tomato)
  • Woody: hard, lignified stems (e.g. tree trunk)

Leaves

• Flat, green organs that carry out photosynthesis
• Structures:
  • Blade: flat part of the leaf
  • Petiole: stalk that attaches leaf to stem
  • Veins: transport water, minerals, and sugars
• Functions:
  • Photosynthesis: convert light energy into chemical energy
  • Respiration: release oxygen and absorb carbon dioxide
  • Transpiration: release water vapor into the air

Flowers

• Reproductive structures that produce seeds and fruits
• Structures:
  • Petals: colorful parts that attract pollinators
  • Sepals: green, leaf-like parts that protect the bud
  • Stamen: male reproductive organs (filaments and anthers)
  • Carpels: female reproductive organs (stigma, style, and ovary)
• Functions:
  • Attract pollinators (e.g. bees, butterflies)
  • Produce seeds and fruits

Fruits

• Mature ovary of a flower, containing seeds
• Functions:
  • Protect and nourish seeds
  • Disperse seeds away from parent plant
• Types of fruits:
  • Simple fruits (e.g. banana, tomato)
  • Aggregate fruits (e.g. raspberry, strawberry)
  • Composite fruits (e.g. pineapple, fig)