Plant Transportation Systems

Autotrophs

  • Autotrophs produce their own energy through photosynthesis, converting solar energy into glucose.
  • Glucose is then converted into ATP (energy) via respiration.
  • Plants have specialized cells organized into tissues, organs, and organ systems for growth and function.
  • Three main systems in plants:
    • Root system
    • Shoot system
    • Reproductive system

Specialized Cells and Tissues

  • Plants have specialized cells that work together to form specialized tissues.

Root Hair Cells

  • Root hair cells have hair-like extensions, increasing the surface-area-to-volume ratio (SA:V).
  • Increased SA:V maximizes water diffusion from the soil into the plant via osmosis.
  • Water is transported to the leaves for photosynthesis.
  • Root cells undergo cellular respiration for energy to grow and repair.
  • The long, thin shape maximizes oxygen intake and carbon dioxide removal.

Palisade Mesophyll Cells

  • Located on the upper side of the leaf, just below the upper epidermis.
  • Upper epidermis cells have a waxy layer to prevent water loss.
  • Most photosynthesis occurs in palisade cells.
  • Cells are tightly packed and close to the surface to maximize light absorption.
  • Contain many chloroplasts to perform photosynthesis.

Guard Cells (Stomata)

  • The waxy cuticle layer prevents gas or water from entering or leaving the leaf, thus controlling water loss.
  • Gases and water vapor transport occurs through stomata, pores in the epidermis.
  • Stomata are usually located on the lower side of the leaf in the lower epidermis layer.
  • Pores are formed by two guard cells containing chloroplasts, which open and close to regulate gas exchange.
  • Guard cells respond to light (opening at daybreak, closing at night) and hydration levels.
  • Stomata close if the leaf is losing too much water; they remain open if humid and well-hydrated.
  • "Turgid" is the scientific term for "swollen".

Stomata Function

  • Observation (Knowledge) “What”: Guard cells are found on the surface of leaves in plants and are responsible for regulating the plant's water loss by closing and opening tiny pores called stomata.
  • Linking statement “How”: When the guard cells need to allow gas exchange for photosynthesis to occur they take up water, swell and become turgid opening the stomata,
  • Inference “why”: but when plants need to reduce water loss, the guard cells release water and become flaccid causing the stomata to close.

Stomata in Different Plants

  • Adaptations are traits that enable the survival of a species.

Plant Adaptations

  • Waxy coating on epidermis: Regulation of water, preventing loss and preventing contact with air currents.
  • Sunken guard cell: Air gets trapped increasing humidity within the space and reducing the concentration gradient for osmosis to occur leading to lower transpiration rates
  • Allelopathic: Toxins are released into ground preventing growth of other plants surrounding it.

Xerophytic Plants and Sunken Stomata

  • In xerophytic plants, sunken stomata are a crucial adaptation for survival in arid environments.
  • Sunken stomata reduce water loss by trapping air, increasing humidity, and reducing the concentration gradient for osmosis, leading to lower transpiration rates.