2026-05-13 19:06

Status: #new

Tags: #biology #plants

Plant Tissue

• 4 types of plant tissue:
  • Meristematic Tissue
  • Dermal Tissue
  • Vascular Tissue
  • Ground Tissue

Meristematic Tissue

• Similar to human stem cells
• Can undergo rapid mitosis $\to$ they are undifferentiated
• Develop into specialized cells when they mature

3 types of Meristematic tissue

Apical Meristem

• Shoots and roots elongate due to apical (tips) meristem

Intercalary Meristem

• Allow grass plants to continue to regrow from the stem

Lateral Meristem

• Allows plants to grow in diameter
• Vascular Cambium adds to plant diameter (found in all plants)
• Cork Cambium adds a woody later (only in woody plants)

Dermal Tissue

• Dermal Tissue is the outer protective layer of cells
• The outer most layer of cells (in non-woody plants) is known as the Epidermis

3 Types of Dermal Tissue

Guard Cells

• These are a pair of kidney shaped cells that form a structure around the stoma (stomata) where plants have holes for gas exchange
• When turgid, they stiffen, as the stoma opens
• Becomes flaccid when stoma closes
• Signals within cells control where a stoma is opened or closed

Trichomes

• Small hair growths on a plants surface
• Keeps plant surface cool and moist
• Secretes protective substances
• Physically punctures predators

Root Hairs

• Tiny structures to increase surface area
  • This helps secure the plant in the soil
  • Maximize nutrient exchange

Vascular Tissue

• Runs along the length of a plant to deliver water and nutrients

Two types of Vascular Tissue

Xylem

• Two Tubes:
  • Tracheid (Smaller Diameter)
  • Vessel Elements (Larger-Diameter)
• The xylem is made of hollowed dead cells which transport water and minerals.

Phloem

• Phloem are made of two types of cells
  • Sieve tube elements (non-nuclei containing)
  • Companion cells (nuclei-containing)
• Living tissue that transport nutrient (sucrose) where companion cells maintain both cell types

Ground Tissue

• Ground Tissue accounts for most of the plant
  • Functions include:
  • Photosynthesis
  • Nutrient Storage
  • Structural Support

References