Biology 203 1st Edition Lecture 19 Outline of Last Lecture I. What is secondary growth?II. Which plants do and don’t do true secondary growth?III. Axial and radial systemsIV. Secondary growthV. Rays, periderms and barkVI. Gymnosperm woodVII. Anthophyte woodVIII. Annual RingsOutline of Current Lecture I. Animal Support and TransportII. SpiculesIII. Hydrostatic SkeletonIV. ExoskeletonsV. EndoskeletonsVI. CartilageVII. BoneVIII. Aquatic AnimalsCurrent LectureI. Animal Support and Transporta. Volume represents mass that must be supported by a super structure or ‘skeleton’b. Skeletal type and composition affects how large animals can becomec. Complexity of support and transport systems depend on surface areai. Larger body sizes require larger support systems and complementary transport systemsii. In some animals, the support system also serves as a transport systemiii. In most animal groups support and circulation are separate organ systemsd. Support systems in animals are formed by cells that produce:i. Connective tissues (bone, cartilage, and chitin)ii. Mineralized structures (calcium carbonate shells)iii. These structures provide structure and attachment sites for muscle (movement)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.II. Spiculesa. Primarily spiculesi. Inorganic materialii. Provide rigidityb. Primarily spongingi. Organic materialii. Provide flexibilityc. Sponges can have both substances to be most efficientIII. Hydrostatic Skeletona. Movement on land requires a requires a closed cavity – a coelomb. Support derived from the pressure of the fluid within the organismc. Pressure at one point (via contraction) has consequences at another pointd. Typically found in aquatic or soil dwelling organismsIV. Exoskeletonsa. Provide external covering for support, protection, and locomotionb. Serves as a protective covering and muscle attachment sitec. Found in most arthropods and mollusksd. Mollusksi. Shell serves as the exoskeletonii. It is secreted by mantle tissue (mostly mineral, non-living material)iii. The shell is produced largely from calcium carbonateiv. Grows WITH the organisme. Arthropodsi. The exoskeleton does not grow with the organismii. Ecdysis (molting) is required for growthf. Protection/Defensei. For many animals, the exoskeleton has evolved into a defense mechanismfrom predationii. Deter predatorsiii. Enhanced for camouflageiv. Constitutive defenses – defenses that are always on regardless of a prey proximity to predatorsv. Inducible defenses – defenses brought about by the presence of a predatorV. Endoskeletona. Provides internal support and protectionb. Serves as muscle attachment sitec. Grows with the other tissuesd. Found in echinoderms and chordatese. Echinodermata- Composed of CaCO3 (Calcium carbonate) and connective tissuef. Chordata - Composed of calcium phosphate and/or cartilageg. The largest animals have endoskeletonsi. Increased mass = increased weight bearingh. Specialized connective tissuei. Bone or cartilageii. Living tissue grows with organismVI. Cartilagea. Flexible connective tissue found in jawless fish, cartilaginous fish, and parts of all vertebratesb. Dense tissue composed of collagen and elastin fibers for flexibility and strengthc. Has no direct blood supplyd. Diffusion of gas and nutrients through matrixVII. Bonea. Type of dense connective tissue that is rigid and contains living cellsb. Structural support and rigidityi. Osseous tissue (calcium phosphate)ii. Collagen – a little flexibilityc. Living cells (osteocytes) in matrixd. Compact bone on exteriore. Spongy bone in interiorf. Cancellous bone is highly vascular and frequently contains red bone marrow where the production of blood cells occursVIII. Aquatic animalsa. Gravity has many constraints on land animalsb. As a fluid medium, water is densec. Neutral or positive buoyancies counteract the effect of gravityd. Surrounding water provides supporte. Cartilage skeletonsf. Bony fishes – extremely reduced bones in limbsg. Marine mammalsi. Spongy and less stiffii. Limb bones are reduced in size and