General Biology 2

• Plant Anatomy


  Deals with structure; in-depth detailed examination to identify position, relations, structure, and function of body parts
• Plant Morphology


  The study of the physical form and external structure of plants
• Parts of the Plant Body

  • Root System
  • Shoot System
  • Leaf
  • Flower
  • Seed
  • Fruit
• Root System

  1. Primary Root

  2. Lateral Root

  3. Root Hairs - absorbs nutrients and materials in small crevices

  4. Stele - surrounded by an endodermis with a Casparian Strip; controls water transport

  5. Pericycle/Cambium - provides strength to the root; responsible for the development of lateral roots

  6. Vascular Bundle - located centrally to withstand stretching forces and allows material transport to be controlled
• Shoot System

  1. Epidermis - covers outer surface; functions to waterproof and protect the stem; controls gas exchange

  2. Cortex and Pith - found internally; transport and storage of materials

  3. Cambium - lateral growth of the stem

  4. Vascular Bundles - to resist compression and bending near the outer edge of the stem
• Leaf

  1. Palisade Mesophyll - the site of photosynthesis; facing the sunlight

  2. Spongy Mesophyll - the main site of gas exchange

  3. Stomata - on the underside of the leaf; maintains an open channel for gas exchange

  4. Vascular Bundles - located centrally; includes xylem and phloem
• Flower is present in angiosperms and possesses colorful petals or sepals, bearing the reproductive parts
• Seed is the mature ovule of a flowering plant, considered as the embryo
• Fruit is a seed-bearing structure of a plant formed from the ovary
• Modifications of Plant Parts

  • Tap Roots
  • Adventitious Roots (For Food Storage)
  • Adventitious Roots (For Support)
• Types of Tap Roots

  • Conical Roots - broad at the base, conical at the apex, e.g., carrot
  • Fusiform Roots - swollen in the middle, tapering towards both ends, e.g., radish
  • Napiform Roots - spherical at the base, tapered toward the apex, e.g., turnip
  • Tuberous Roots - no specific shape, thick and fleshy, e.g., sweet potato
• Types of Adventitious Roots for Food Storage

  • Simple Tuberous Roots - swollen and do not assume any shape, e.g., sweet potato
  • Nodulose Roots - single beads, swollen at the apex and have a definite shape, e.g., ginger
  • Fasciculated Tuberous Roots - the cluster of adventitious roots for food storage, e.g., Dahlia
  • Moniliform Roots - swollen and constricted, e.g., grasses
  • Annulated Roots - discs placed one over the other, e.g., Ipecac
• Types of Adventitious Roots for Support

  • Prop Roots - developed from the branches of the tree, hanging downwards and penetrating the ground
  • Stilt Roots - grows obliquely from the basal node of the stem
  • Climbing Roots - arise from the nodes and attach themselves to some support to climb over it
  • Clinging Roots - enters the crevices of some support and fixes the plant
  • Buttress Roots - vertically elongated basal part of the stem which spread in different directions in the soil
• Plant Physiology


  Deals with the ways that plants function
• Plant Nutrition


  Refers to the supply and absorption of chemical compounds for the growth and metabolism of the plant
• Essential Elements and their Function in Plants

  • CHO - Major constituent of organic plant material; assimilation of redox reactions
  • B - Mitotic activity for root development
  • Ca - Structural component of the cell wall and membrane
  • Cl - Water splitting system of PSII; stomatal opening regulation
  • Cu - Co-factor for metalloprotein
• Elements and their functions in plants

  • CHO: Major constituent of organic plant material; assimilation of redox reactions
  • B: Mitotic activity for root development
  • Ca: Structural component of the cell wall and membrane
  • Cl: Water splitting system of PSII; stomatal opening regulation
  • Cu: Co-factor for metalloproteins and enzymes
  • Fe: Regulatory component of proteins and metabolites
  • Mg: Chlorophyll synthesis
  • Mn: Photodestruction of chlorophyll and chloroplast structure
  • Mo: Enzyme activation; chlorophyll synthesis
  • Ni: Root nodule growth
  • N: General plant growth of roots, stem, and leaf
  • P: Energy transferring process of photosynthesis and respiration
  • K: Cell extension and stomatal regulation; enzyme activation; photosynthetic activity
  • S: Assimilation of redox reactions
  • Zn: Enzymatic function and reactivity; stem elongation; protein and starch synthesis
• Vascular Tissue System components

  • Xylem: Sends water and dissolved minerals from the roots to the upper parts of the plant; Tracheids: tapered, thick, found in gymnosperms; Vessels: long tube, has perforation plates, common in angiosperms
  • Phloem: Sieve tube members: large, cylindrical, tapered; functional without nuclei; connected by sieve plates; Companion cells: adjacent to sieve tube; has nuclei; transports to other plant parts
• Reproduction and Development of Flowering Plants


  • Meristems: Apical Meristems - plant lengthening; responsible for primary growth; gives rise to primary tissues and grows new leaves and fruits; Lateral Meristems - plant widening; responsible for secondary growth to support an increase in width e.g. bark; Intercalary Meristems - regenerates the parts removed by grazing animals in grasses
  • Growth Rings: Dead xylems; each ring marks the passage of one year, which is used to estimate the age of the plant (dendrochronology)
  • Apical Dominance: Auxin production prevents growth in lateral buds, ensuring the plant grows up towards the light
• Plant Hormones and their functions

  • Abscisic Acid (ABA): Seed germination, leaf senescence, stomatal aperture, adaptation to environmental stress
  • Auxin: Stimulates cell elongation; growth of pre-existing roots
  • Brassinosteroids: Abiotic stress responses; seed germination; reproductive development; regulates plant defense
  • Cytokinin (CK): Seed development; cell differentiation; chloroplast formation
  • Ethylene (ET): Defense from necrotrophic pathogens; fruit ripening
  • Gibberellins (GA): Response to nutritional limitation
  • Jasmonic Acid (JA): Defense from necrotrophic pathogens and herbivore insects; tendril coiling, leaf senescence, fruit ripening, tuber formation, stomatal opening
  • Salicylic Acid (SA): Defense response from biotrophic and hemi-biotrophic pathogens
• Plant growth and development are controlled by plant hormones (phytohormones)
• Methods of Sexual Reproduction in Flowering Plants

  • Vegetative propagation (asexual reproduction from plant cutting)
  • Spore formations (e.g. mould, ferns)
  • Pollen transfer (flowering plants or angiosperms)
• Pollination

  The transfer of pollen grains from an anther to a stigma
• Fertilization


  Fusion of a male gamete with a female gamete to form a zygote
• Seed Dispersal

  Fertilization of gametes results in the formation of seeds
• Seed Dispersal

  Fertilization of gametes results in the formation of a seed, which moves away from the parental plant
• Cross-pollination


  The transferring of pollen grains from one plant to the ovule of a different plant
• Animal Morphoanatomy


  The study of anatomical forms and structures with an emphasis on characteristics useful in distinguishing the species
• Bilateral Symmetry


  Divides an organism into mirror image halves
• Radial Symmetry


  The organism can be divided into similar halves by passing at a plane at any angle along a central axis
• Spicules

  Small needlelike or sharp-pointed structures of calcite or silica that make up the skeleton of a sponge. Can be megascleres or microscleres
• Classes of Phylum Porifera

  • Demospingiae
  • Sclerospongiae
  • Calcarea
  • Hexactinellida
• Classes of Phylum Cnidaria

  • Cubozoa
  • Scyphozoa
  • Anthozoa
  • Hydrozoa
• Worm Phyla

  • Platyhelminthes
  • Nematoda
  • Annelida
• Classes of Phylum Echinodermata

  • Crinoidea
  • Asteroidea
  • Echinoidea
  • Holothuroidea
  • Ophiuroidea
• Classes in Phylum Echinodermata

  • CLASS CRINOIDEA - sea lilies and feather stars
  • CLASS ASTEROIDEA - sea stars
  • CLASS ECHINOIDEA - sea urchins
  • CLASS HOLOTHUROIDEA - sea cucumbers
  • CLASS OPHIUROIDEA - basket stars and serpent stars, or brittle stars
  • CLASS CONCENTRICYCLOIDEA - sea daisies
• Phylum Arthropoda

  • They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated segments, and paired jointed appendages
• Subphylums in Phylum Arthropoda

  • SUBPHYLUM CHELICERATA - chelicerates; arthropods without jaws (e.g., spiders, scorpions)
  • SUBPHYLUM MYRIAPODA - multi-segmented, each segment bears a pair of legs (e.g., millipedes, centipedes)
  • SUBPHYLUM CRUSTACEA - body segmented, covered with carapace (e.g., shrimp, crabs)
  • SUBPHYLUM HEXAPODA - Class Insecta. Divided into two subclasses, apterygota (wingless insects) and pterygota (winged insects)
• Phylum Chordata


  • Single, hollow nerve cord beneath dorsal surface; brain and spinal cord
  • Notochord: flexible rod on the dorsal side of gut
  • Pharyngeal slits connect pharynx with outside gills
  • Postanal tail extends beyond anus; it regresses into the tailbone in humans
  • Segmentation: reflected in arrangement of muscles and vertebral column
• Subphylums in Phylum Chordata

  • SUBPHYLUM UROCHORDATA - Commonly called Tunicates. Sessile marine animals as adults- motile as larva
  • SUBPHYLUM CEPHALOCHORDATA - Commonly known as Lancets. Have all features of the ideal chordate. Bury themselves in sand, and filter-feed through mouth
  • SUBPHYLUM VERTEBRATA - The vertebrates. 7 extant classes. 3 fishes, 4 tetrapods. All possess some form of segmented vertebra