Different Cell Types of Plant and Animal Tissues

Plant Tissues

  • Dermal tissue

    • Epidermis: single outer cell layer; cuticle reduces water loss; root hairs increase absorption; trichomes limit sunlight; guard cells flank stomata

  • Ground tissue

    • Parenchyma: thin-walled, large vacuoles; photosynthesis, storage, light & gas passage
    • Collenchyma: unevenly thickened, flexible walls; supports growing regions just below epidermis
    • Sclerenchyma: lignified, very thick walls; dead at maturity; provides rigid support (fibers & sclereids)

  • Vascular tissue

    • Xylem: non-living tracheids & vessel elements; transports water/minerals root➜shoot
    • Phloem: sieve-tube elements (no nucleus) + companion cells; transports sucrose/organics bidirectionally

Animal Tissues

  • Epithelial

    • Simple squamous (flat): blood vessels, alveoli
    • Simple cuboidal (box-like): kidney tubules, glands
    • Simple columnar (tall): digestive tract, oviducts (with microvilli/cilia)
    • Stratified: protective lining (skin, mouth, vagina)
    • Glandular: unicellular (goblet) or multicellular secretory units

  • Connective

    • Loose (areolar): elastic support around organs
    • Dense (fibrous): collagen-rich tendons & ligaments
    • Specialized
      • Reticular: lymphoid organs
      • Cartilage: chondrocytes in lacunae (hyaline, elastic, fibro-)
      • Bone: osteoblasts, osteocytes (lacunae), osteoclasts; rigid ECM
      • Blood: erythrocytes, leukocytes, thrombocytes in plasma
      • Adipose: adipocytes store lipids; white (adults) & brown (infants) fat

  • Muscular

    • Skeletal: striated, multinucleated, voluntary
    • Smooth: non-striated, single nucleus, involuntary (viscera, vessels)
    • Cardiac: striated, single nucleus, branching, involuntary (heart)

  • Nervous

    • Neuron: dendrites (to cell body) ➜ axon (to synapse)
    • Neuroglia: support, nourish, protect neurons

Key Comparisons

  • Support cells: collenchyma (flexible, young plants) vs. cartilage/bone (animals)
  • Transport: xylem & phloem (plants) vs. blood (animals)
  • Protective outer layer: epidermis with cuticle (plants) vs. stratified epithelium/skin (animals)
  • Storage: parenchyma vacuoles & sclereids (plants) vs. adipocytes (animals)

Essential Functions At-a-Glance

  • Cuticle: minimizes transpiration
  • Stomata (guard cells): gas exchange, transpiration regulation
  • Sieve-tube elements: organic nutrient flow; lack nucleus
  • Fibroblasts: synthesize ECM in connective tissue
  • Chondrocytes: maintain cartilage matrix
  • Osteoclasts: bone resorption, calcium release
  • Actin & myosin filaments: basis of muscle contraction