Competitive Exams: Revision Terminology Part 14

Stomata

  1. Apple & Mulberry type – only on lower side – Walnut, Oak, Peech.

  2. Potato type – more on lower side – most plants

  3. Oat type – equal on both side – maize, oat.

  4. Water lily – Only upper surface - lotus

  5. Potamogeton type – inactive – in submerged plants.

Ground tissue system

(i) Extrastelar – Hypodermis, cortex, endodermis

(ii)Intrastelar, pericycle, medullary rays, medulla

Primary structure of dicot stem

  1. Epidermis – outermost, maintain shape, impermeable to liquid & gases, prevent water loss, multicellular hairs.

  2. Cortex – of parenchyma, protective, support, storage.

    1. Hypodermis – multilayered, mechanical support

    2. General cortex – Parenchyma, mechanical support

    3. Endodermis - innermost

  3. Vascular tissue – from procambium – centrifugally end arch open, Collateral arranged in ring, Intrafasicular Cambium between xylem & phloem

  4. Pith – parenchymatous, Central, Medullary rays – storage & conduction

  • Primary Structure of monocot stem – no cambium (closed VB)Scattered, no difference of pith & cortex Epidermis Hypodermis (Thick wall, Lignified, Sclerenchymatous)

  • Each Vascular Bundle is surrounded by Bundle sheath (Sclernchymatous)

  • Conjoint, Collateral, end arch, (In Triticum – pith cavity present)

  • Secondary Growth

    1. Cambium between xylem & Phloem = Intrafasicular Cambium

    2. Parenchymatous cell between Vascular Bundle – meristamatic -> Interfasicular Cambium

  • (1) & (2) from vascular cambium

    1. Fusiform initial – Narrow, elongated

      1. Secondary phloem – outer

      2. Secondary xylem – inner

    2. Ray initial – Spherical, parenchymatous.

  • Monocot leaf – motor or bulliform cells – Rolling of leaves in dry weather

  • Roots of epiphytes & aquatic plants may contain chloroplasts

  • Stele dicot stem = Eustele

  • Monocot dicot stem = Atactostele

  • Protoxylem lacuna = schizo-lysogenous cavity

  • Pith cavity – Ricinus in dicots.

  • Root – endodermis -> Casparian strips (barrage) -> Prevent leakage of nutrients -> passage cells – allow radial diffuser of water

  • Dicot root = 3 – 6 strands – exarch

  • Monocot root – polyarch = exarch

  • Lateral roots arise from pericycle – inner layer of parenchyma – endogenous.

  • Xylem – bulk of root after secondary growth

  • Rounded Cork cell in lenticel = complementary cells (have inter cellular space & allow diffusion)

  • Wood = secondary xylem formed by Vascular Bundle cambium during secondary growth

    1. Wood angiosperm – vessel present – porous, hardwood

    2. Gymnosperm – no vessel – non porous, soft wood

  • Roots annual rings not well marked due to uniform temperature (except willow).

  • Wood can be Heartwood – deal, dark, more durable, resistant to microorganisms – Extractive or Sapwood – peripheral, wetter, light, water conducting

  • In Wounds callus forms the proturberance producing knots.

  • W. Dudgeon initiated ecology in India (father of India ecology = R. Misra)

  • Development of a communing related to set of condition = sere -> last = climare

  • Plant growing in savanna = psilophytes.

  • Plants growing in desert/stepper = Eremophytes.

  • Succulents (drought avoiding)

  1. Stem – opumitia, Euphorbia, E.Splendens, E.Tirucalli, areus.

  2. Leaf – aloe, agave, Begonia, Bryophyllum.

  3. Root – Asparagus, ceiba parviflora