Biodiversity of Animals(11)

Asymmetrical, Radial Symmetry, Bilateral Symmetry.

Animals that have no symmetry, they are sessile. E.g. sponges.

Animals that can be divided into two mirror images through any vertical plane. Their bodies are arranged around a central axis. Common in sessile, free floating. Locomotion is not very efficient.

Animals that have a right and left half that are mirror images when cut lengthwise. They move efficiently with paired limbs. They show cephalisation.

The concentration of organs, especially sense organs, feeding appendages, and nervous tissue near the anterior and of the animal.

Skin and nervous system

Tissues, organs and systems like excretory or reproductive systems.

Digestive system.

They have two layers of tissue (ectoderm and endoderm). Their development is limited as they cannot develop organs.

Have three layers of tissues ( ectoderm, mesoderm and endoderm). This allows for tissue differentiation to perform specialised functions (organs)

Taking in food and expelling waste through the same opening. Not a very efficient system.

-Mouth and an anus -This is efficient, they can eat more when food is still in the gut, this causes specialisation of parts e.g. ingestion, digestion, absorption etc. in various parts such as stomach, small intestine.

No body cavity between ectoderm and endoderm. Single opening to sac-like digestion cavity. May be diploblastic or triploblastic.

Contains a body cavity Contains a mesoderm which holds complex organs and systems

Allows space for complex organs and systems to develop Soft bodied organisms - fluid in coelom allows for efficient hydrostatic force Allows independent movement of gut and other muscles e.g.: peristalsis is separate from locomotion

-Asymmetrical -Sessile -Aquatic -Acoelomate -No body openings -Cellular level of organisation -embedded in a jelly-like substance -Protected by a skeleton of minute spicules bringing food to cells. -Have flagellated collar cells that line the interior cavity of sponge, as the flagella beat up and down, water is drawn through the cavity. -digestion takes place intracellularly and excretion and respiration occur by diffusion.

-Simple body plan, more complex than sponges -Aquatic -Acoelomate -Radial Symmetry -Diploblastic -With a mesoglea (not mesoderm), a layer of jelly between 2 layers. -Digestive cavity with single cavity -Tentacles with stinging cells for stinging and capture of prey and defence against predators. -Two basic body forms (Polyp and Medusa) -Jelly fish, anemones and blue bottles

Polyp: Cylindrical shaped which are sessile, sea anemones and corals Medusa: Free-floating and umbrella shaped, jelly fish and blue bottles.

• Flat worms -Mostly internal parasites -Dorsoventrally-flattened, unsegmented worms -Acoelomate -One gut opening -Bilateral symmetry -Cephalisation -Triploblastic, with organs. -Tape worms, planarians

-Segmented worms -Bilateral symmetry -Cephalisation -Triploblastic -True coelom (body cavity is surrounded by a mesoderm) -Through gut -Earth worms, polychaetes, leeches

-Adaptable body plan -Bilateral symmetry -Cephalisation -Triploblastic -Coelomate -Through gut -Segmented -Haemocoel (blood filled space with an open blood system) -Chitin and cuticle make a waterproof exoskeleton -Show metamorphosis -Jointed appendages (modified for special functions e.g. mouth parts legs. -Complex muscular system

Marine animals Extinct, mostly fossilised

-Spiders, mites, scorpions -Have chelicerae: pincer-like mouth parts -4 pairs of legs -No antennae -8 simple eyes -2 body divisions (cephalothorax and abdomen)

-Millipedes, centipedes -Many body segments -1 or 2 pairs of legs per segment -1 pair of antennae -Simple eyes -2 body sections (head and trunk)