Human Biological Systems, Organisation of the Body Assignment

Human Biological Systems, Organisation of the Body - Assignment Example liverworts, mosses Pteridophytes These are vascular plants which characteristically do not produce flowers and seeds. Reproduction takes place via the dispersion of spore. The dominant generation is saprophytic. Have true roots. Club mosses, ferns, horsetail Gymnosperms These are seed producing plants and seeds develop to form cones. They produce unisexual flowers. pines, ephedra, juniper, fir, redwood Angiosperms These are seed producing plants and are known as flowering plants. They show derived characteristics and produce flowers, endosperms, and fruits. Water lilies, black pepper, bluebells, cucumber (SOLOMON & MARTIN, 2005). TAQ 2. Flowering plants Monocotyledons Flowering plants Dicotyledons Monocotyledons consist of 55,000 species and are predominantly herbaceous Dicotyledons consist of 165,000 species and are woody stemmed plants The primary root soon aborts and the mature root system becomes adventitious Mature root system either primary or adventitious or both Consist of a single cotyledon Consist of two cotyledons Intrafascicular cambium is not present and leaves are parallel veined Intrafascicular cambium is present and leaves are mostly net veined Vascular bundles are scattered in two or more rings Vascular bundles are present in the form of a ring surrounding pith Floral parts are borne in sets of 3 and sometimes 4 Floral parts are borne in sets of 5 Pollen is typically triaperturate Pollen is uniaperturate (KOKWARO, 1994). TAQ 3. Classes Characteristics Examples Jelly fish, Anemones (Coelenterates) Aquatic, mostly marine and body cavity has a hypostome. The hypostome is surrounded by sensory tentacles Corals, hydra Flatworms (platyhelminthes) Flatworms are bilaterally symmetrical and have no internal body cavity. Have a distinct head and tail and have no specialized circulatory and respiratory system Planaria, tapeworms, flukes Round worms (nematodes) Non-segmented worms, bilaterally symmetrical, body has a complex cuticle around it. Ascaris lumb ricoides, Enterobius vermicularis Ringed Worms (annelids) Have elongated bodies divided into segments and are called segmented worms. The worms exist in different shapes and colors. Body cavity is lined by mesoderm and have a closed circulatory system Earthworms, leeches Snails, slugs, squids (Molluscs) Non segmented worms, have a mantle and an internal as well as external shell. A radula is also present Octopus, mussels, tusk shells Star fish, sea urchin (Echinoderms) Have a radial symmetry and the central body has several protruding arms. Tube feeds with suction pads are also present Sand dollars, sea stars Insects, spiders, crabs (Arthropods) Have segmented bodies with paired segmented appendages. Have bilateral symmetry and a chitnous exoskeleton Scorpions, centipedes, millipedes (THORP & COVICH, 1991) TAQ. 4 Classes Characteristics Examples Spiders, ticks, mites, daddy Longlegs, scorpions (Arachnida) They make webs and have two body regions. They have chelicerae and very long l egs Rust mite, clover mite, black widow spider Centipedes (Chilopoda) Segmented bodies with a single pair of legs on each segment. Have a single pair of antenna Blue ring centipede, stone centipede, earth centipede Millipedes (Diplopoda) Segmented bodies with two pairs of legs on each segment. Have a single pair of antenna. Pill millipede, bristly millipede, spotted millipede Crabs, lobsters (Crustacea) They have three major body segments namely head, thorax and abdomen. Have two pairs of antenna. They have