Plant Parts: Roots and Stems

Plant Parts

Roots

• Underground plant structures that absorb water and nutrients from the soil
• Anchor the plant in place and store food
• Types:
  • Taproot: single, main root that grows straight down (e.g., carrots)
  • Fibrous root: many small roots that spread out (e.g., grasses)
  • Adventitious root: roots that grow from stems or leaves (e.g., ivy)

Stems

• Above-ground plant structures that support the plant and transport materials
• Functions:
  • Support leaves, flowers, and fruits
  • Transport water, nutrients, and sugars between roots and leaves
  • Store food and water
• Types:
  • Herbaceous stem: soft, green stem that dies back to the ground at the end of the growing season (e.g., tomato plants)
  • Woody stem: hard, brown stem that persists for many years (e.g., trees)

Leaves

• Organs that carry out photosynthesis, producing energy for the plant
• Structure:
  • Blade (lamina): flat part of the leaf where photosynthesis occurs
  • Petiole: stalk that attaches the leaf to the stem
  • Veins: tubes that transport water, nutrients, and sugars
• Functions:
  • Absorb light energy and convert it into chemical energy
  • Release oxygen and absorb carbon dioxide
  • Regulate water loss through transpiration

Petals

• Colorful, often fragrant structures that attract pollinators (e.g., bees, butterflies)
• Typically found in flowers, which are reproductive structures
• Functions:
  • Attract pollinators to facilitate fertilization
  • Protect the reproductive organs (stamens and pistils)
  • Provide nectar and other rewards for pollinators

Seeds

• Reproductive structures that contain the embryo of a new plant
• Functions:
  • Contain stored food and nutrients for the developing embryo
  • Protect the embryo from environmental stressors
  • Facilitate dispersal and germination of the new plant
• Structure:
  • Seed coat: protective outer layer
  • Endosperm: stored food and nutrients
  • Embryo: immature plant that will grow into a new individual

Plant Parts

Roots

• Absorb water and nutrients from the soil, anchor the plant, and store food
• Taproot: single, main root that grows straight down (e.g., carrots)
• Fibrous root: many small roots that spread out (e.g., grasses)
• Adventitious root: roots that grow from stems or leaves (e.g., ivy)

Stems

• Support leaves, flowers, and fruits, transport materials, and store food and water
• Herbaceous stem: soft, green stem that dies back to the ground at the end of the growing season (e.g., tomato plants)
• Woody stem: hard, brown stem that persists for many years (e.g., trees)

Leaves

• Carry out photosynthesis, producing energy for the plant
• Consist of blade (lamina), petiole, and veins
• Absorb light energy, convert it into chemical energy, and release oxygen
• Regulate water loss through transpiration

Flowers and Petals

• Colorful, often fragrant structures that attract pollinators (e.g., bees, butterflies)
• Attract pollinators to facilitate fertilization, protect reproductive organs, and provide nectar and rewards

Seeds

• Contain the embryo of a new plant, stored food and nutrients, and protect the embryo
• Consist of seed coat, endosperm, and embryo
• Facilitate dispersal and germination of the new plant