A large fraction of the thermal energy generated in the engine of a car is rejected to the air by the radiator through the circulating water. Should the radiator be analyzed as a closed system or as an open system? Explain.
General Zoology Week 8, Exam 4 Material Phylum Arthro pod : jointed foot legs) Consists of over 1 million species and makes up about 80% of all living species Can be found in all freeliving habitats Organization I. Features of the first arthropods—trilobites Trilobites—marine organisms that lived between 550200 MYA External Features: head & trunk regions o Biramous (two branched) appendages; found in other primitive, aquatic arthropods like horseshoe crabs o One pair of antennae and one pair of compound eyes Ommatidia: lightsensing units of compound eye o No specialized mouthparts Exoskeleton hard outer covering o Protects body o Allows for efficient muscle attachment o Allows legs to be rigid and jointed o Usually made of chitin a polysaccharide (sugar polymer) similar to cellulose; chitin can be combined with: Protein to be tough, yet flexible Protein and tanning compounds (i.e. Phenol) to be hard and brittle Movement and muscles o Dorsal and ventral longitudinal muscles move body segments o Protractor and retractor muscles move legs forward and backward, respectively o Extender and flexor muscles move legs away from and toward the body’s midline, respectively Nervous system o Supraesophageal ganglion functions as the brain o Circumesophageal connective connects upper and lower ganglia o Subesophageal ganglion controls feeding and mouthparts o Ventral nerve cord o Segmental ganglia controls muscles and legs of segments Circulatory system o Open system (hemocoel blood cavity) Digestive system o The ectodermis, which secretes chitinous material, invagenates, or pushes in on itself, to form the foregut and hindgut o The endodermis, which does NOT secrete chitinous material, opens to form the midgut o Foregut food storage and/or grinding o Midgut absorption of nutrients o Hindgut water absorption II. Terrestrial Adaptations in Arthropods Terrestrial Adaptations are present in three lineages: oArachnida (scorpions, spiders, ticks, mites, etc.) oMyriapoda (centipedes and millipedes) oInsecta (I think you get the picture) Excretory Products o Unlike aquatic arthropods which produce ammonia or annelids and onychophorans which produce urea, terrestrial arthropods uric acid (insects) and guanine (spiders and scorpions); producing these wastes requires a higher energy cost, but it allows the waste to be less toxic and conserve more water Excretory System o Malpighian Tubules (M.T.): tubular extensions from the gut that remove guanine or uric acid from the blood (hemolymph); tubules are located between the midgut and hindgut Guanine and water are removed from the blood by the M.T. Guanine and water are then moved to the hindgut where the water is reabsorbed and the guanine is excreted Respiratory System o Tracheae that carry air directly to tissues (found in myriapods, insects, and some arachnids) o Lungs that oxygenate blood (only found in arachnids; one pair of book lungs) III. Arthropod Diversity Subphylum Chelicerata oNamed for their chelicerae: mouthparts formed from pincers at the ends of appendages oBody consists of two main parts: Cephalothorax: front section of animal built for feeding and locomotion; houses the chelicerae, walking legs, and a pair of pedipalps, which can function as tactile organs (spiders) or as large, modified weapons (claws of scorpions) Abdomen: back section of animal built for respiration o Other feature include a loss of antennae, a primitively marine ancestry, and the presence of coxal glands (used for collecting and excreting waste) o Earliest members: Sea scorpions (Eurypterids); large marine predators that lived 500 to 225 MYA o Class Arachnida—Terrestrial chelicerates Respiration book lungs and/or tracheae Excretion Malpighian tubules, guanine Reproduction sperm transfer and internal fertilization Superclass Myri pod : many legs o Centipedes: 8,000 species, 20 to over 300 pairs of legs o Millipedes: 12,000 species, 34 to over 400 pairs of legs o Retained Primitive Features: Head and trunk regions One pair of antennae Compound eyes o Terrestrial Adaptations: Uniramous (single branched) appendages Uric acid production Malpighian tubules o Centipedes: Class Chilo po (Mouth foot) Fast moving predators One pair of legs per segment Flat body poison claws (modified first legs held underneath mouthparts) No defensive secretions o Millipedes: Class Diplo pod (Two feet) Slow moving detritivores Two pairs of legs per segment No poison claws Defensive secretions (some can produce a form of cyanide)