Animalia, Plantae, Fungi Taxonomy

• Taxonomy classifies organisms into Kingdom Animalia, Kingdom Plantae, and Kingdom Fungi.

Kingdom Animalia: Phyla and Classes

• Consists of multicellular, eukaryotic organisms that are heterotrophic and lack cell walls.
• Classified into various phyla based on body structure.

Phylum Porifera

• Porifera have many tiny pores (ostia) through which water flows, exiting through a large opening (osculum).
• They live in water, mostly in the ocean, attached to surfaces.
• These are filter feeders that suck in water, trap food, and expel water.
• Porifera lack real organs, such as a brain, heart, or stomach.
• Their bodies are supported by spicules or spongin, which act as a skeleton.
• Sponges are an example of Porifera.

Phylum Cnidaria

• Cnidaria primarily live in the ocean, with some in freshwater.
• These have tentacles with stinging cells (cnidocytes) used to catch prey and defend.
• Their body exhibits radial symmetry, arranged around a central point.
• Cnidaria have two body forms:
  • Polyp (sea anemones and corals): Attached to a surface.
  • Medusa (jellyfish): Free-swimming and umbrella-shaped.
• Cnidaria boast of a simple body structure, lacking a brain or bones, with only a mouth and a body cavity.
• Tentacles are used to capture food and bring it to the mouth.
• Reproduction occurs in two ways:
  • Asexual (budding in polyps).
  • Sexual (releasing eggs and sperm in water).
• Corals form colonies of tiny polyps.
• Examples include Class Hydrozoa (Hydras), Class Scyphozoa (Jellyfish), and Class Anthozoa (Corals, Sea Anemones).

Phylum Platyhelminthes

• Platyhelminthes have flat, soft bodies that aid in oxygen absorption.
• Their bodies exhibit bilateral symmetry, divided into two equal halves.
• Lacking a skeleton or segments, they are soft-bodied and unsegmented.
• They can be parasitic, living inside other animals such as tapeworms and flukes.
• Some are free-living, residing in water or moist soil, like planarians.
• Platyhelminthes possess a simple digestive system with only one opening for food and waste, except for tapeworms that absorb food through their skin.
• They lack a circulatory or respiratory system, absorbing oxygen through their skin.
• Reproduction occurs sexually or asexually, with some capable of regenerating body parts.
• Examples include Class Turbellaria (free-living flatworms), Class Trematoda (flukes), and Class Cestoda (tapeworms).

Phylum Nematoda

• Nematoda have round, smooth, long, thin, and cylindrical bodies.
• Bodies exhibit bilateral symmetry, with left and right sides as mirror images.
• They are unsegmented, unlike earthworms.
• Nematoda possess a complete digestive system with a separate mouth and anus.
• They are found almost everywhere (soil, water, plants, and animals).
• Some are parasites infecting humans, animals, and plants (e.g., hookworms, pinworms).
• Nematoda move by thrashing, using muscles to wiggle side to side.
• Nematoda reproduce sexually with separate male and female worms.
• Examples include Ascaris lumbricoides, hookworms, pinworms, and filarial worms.

Phylum Annelida

• Annelida have segmented bodies divided into repeating sections.
• They exhibit bilateral symmetry.
• Annelida have a true body cavity (coelom) that aids in movement and organ function.
• They have a complete digestive system with a separate mouth and anus.
• Most Annelida have a closed circulatory system with blood vessels.
• They live in water or soil.
• Uses muscles and bristles (setae/parapodia) to crawl or swim.
• Reproduction is primarily sexual, though some are hermaphrodites.
• Examples include Class Polychaeta (bristle worms), Class Oligochaeta (earthworms), and Class Hirudinea (leeches).

Phylum Mollusca

• Mollusca are soft-bodied animals, often covered by a hard shell.
• They exhibit bilateral symmetry.
• The body is divided into three parts:
  • Head: Contains sensory organs and mouth.
  • Foot: Used for movement (crawling, swimming).
  • Visceral Mass: Contains internal organs (heart, stomach, intestines).
• Most Mollusca have a shell made of calcium carbonate.
• A mantle secretes the shell.
• Most Mollusca have a tongue-like organ with tiny teeth (radula) for scraping food.
• Aquatic species respire through gills, while land species use lungs.
• Circulatory system can be open (most mollusks) or closed (cephalopods like octopuses and squids).
• Some reproduce sexually, but some are hermaphrodites.
• Examples include Class Gastropoda (snails, slugs), Class Bivalvia (clams, oysters), and Class Cephalopoda (octopuses, squids).

Phylum Arthropoda

• Arthropoda is the largest group of animals, including insects, spiders, crabs, and centipedes.
• They have segmented bodies divided into head, thorax, and abdomen.
• Arthropoda have an exoskeleton made of chitin for protection and support.
• Jointed legs and appendages aid in movement, grabbing, and adapting to various environments.
• They exhibit bilateral symmetry.
• Arthropoda have an open circulatory system where blood flows in open spaces.
• They have highly developed sense organs, like compound eyes, antennae, and sensitive hairs.
• Respiration occurs through gills (aquatic arthropods), tracheal tubes (insects), or book lungs (spiders and scorpions).
• Usually reproduces sexually.
• Molting (ecdysis) involves shedding the exoskeleton as they grow.
• Examples include:
  • Insects: butterflies, ants, and beetles (six legs, wings)
  • Arachnids: spiders, scorpions, and ticks (eight legs, no antennae)
  • Crustaceans: crabs, lobsters, and shrimp (mostly aquatic, two pairs of antennae).
  • Myriapods: centipedes and millipedes (many legs).

Phylum Echinodermata

• Echinodermata are marine animals like starfish, sea urchins, and sea cucumbers.
• Adults exhibit radial symmetry.
• They have spiny or bumpy skin.
• The endoskeleton is made of calcium carbonate plates under their skin.
• Echinodermata feature a unique water vascular system for movement, feeding, and respiration.
• Tube feet, are small suction-like structures aid in movement and capturing food.
• They have a simple nervous system consisting of a nerve ring instead of a brain.
• The ability to regenerate lost arms or body parts.
• Reproduction occurs sexually, with separate sexes releasing eggs and sperm into the water.
• Examples include starfish, sea urchins, and sea cucumbers.

Phylum Chordata

• Chordata include animals like fish, amphibians, reptiles, birds, and mammals.
• The notochord is a flexible rod-like structure that supports the body, which becomes the backbone in some
• Has a dorsal hollow nerve cord, a tube-like nerve structure that forms the brain and spinal cord.
• Pharyngeal slits or gill slits are openings in the throat area; in fish, they develop into gills.
• A post-anal tail extends beyond the anus, present in embryos (some lose it as adults).
• Exhibits bilateral symmetry.
• Chordata have a closed circulatory system with blood flowing in vessels, and most have a heart.
• They reproduce sexually.
• Examples include fish (e.g., sharks, bony fish), amphibians (e.g., frogs, salamanders), reptiles (e.g., snakes, turtles), birds (e.g., eagles, penguins), and mammals (e.g., humans, dogs, whales).

Kingdom Plantae: Phyla and Classes

• Consists of multicellular, eukaryotic, and autotrophic (photosynthetic) organisms.
• Have cell walls made of cellulose.
• Divided into different phyla based on structure and reproduction.
  • Phylum Bryophyta (non-vascular plants).
    • Ex: Class Hepaticae (liverworts), Class Musci (mosses), Class Anthocerotae (hornworts).
  • Phylum Pteridophyta (vascular, spore-producing plants).
    • Ex: Class Filicopsida (true ferns), Class Lycopodiopsida (club mosses), Class Equisetopsida (horsetails)
  • Phylum Gymnosperms (non-flowering seed plants).
    • Ex: Class Cycadopsida (cycads), Class Ginkgopsida (ginkgo), Class Coniferopsida (conifers), Class Gnetopsida (gnetophytes).
  • Phylum Angiosperms (flowering plants).
    • Ex: Class Monocotyledonae (monocots: grasses, lilies), Class Dicotyledonae (dicots: roses, oaks, sunflowers).

Kingdom Fungi: Phylum and classes

• Are eukaryotic, mostly multicellular (except yeasts).
• The group is heterotrophic (decomposers, parasites, or symbionts).
• Cell walls are chitin.
• Fungi reproduce by spores, sexually or asexually.
  • Phylum Chytridiomycota - one of the earliest fungal groups and is unique among fungi due to its production of flagellated spores (zoospores), which allow movement in aquatic environments.
    • Habitat is mostly aquatic, but some are terrestrial.
    • Cell walls are chitin.
    • Both sexual and asexual reproduction.
    • Zoospores have flagella, making them the only fungi with active movement.
    • Some are decomposers, while others are parasites of plants, animals, and other fungi.
    • Ex: Batrachochytrium dendrobatidis – A chytrid fungus responsible for chytridiomycosis, a deadly disease in amphibians. Synchytrium endobioticum – Causes potato wart disease in plants.
  • Phylum Zygomycota - a group of fungi that primarily live in soil or on decaying organic matter. They are best known for their fast-growing molds, such as those found on bread and fruits.
    • Habitat: Found in soil, decaying matter, and as parasites on plants/animals.
    • Reproduction:
      • Asexual reproduction via sporangiospores (spores produced in a sporangium).
      • Sexual reproduction through zygospores, which form when two compatible mating types fuse.
    • Have coenocytic hyphae (multinucleated, without septa/cell walls between cells).
    • Ex. Rhizopus stolonifer – Common bread mold. Mucor – Found in soil and decaying organic material. Pilobolus – Known as the "hat-thrower fungus", it launches spores toward light
  • Phylum Acomycota - the largest group of fungi, known as sac fungi due to their unique spore-producing structure called an ascus. These fungi are found in diverse habitats and include many economically and medically important species.
    • Habitat: Found in soil, decaying organic matter, freshwater, marine, and as plant or animal parasites.
    • Ex. Penicillium, Morchella, Truffles