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Unformatted text preview: Complex insect life cycles 2 types of life cycle 1. Paleopterans (odonata & Ephemeroptera), wings develop externally via progreesive moults, reproductive structures usually develop in adult moult, immutare=nymphs 2. Neoptern Superorders (hemimetabolous life cycle ), abrupt change from wingless larval stage to winged adult (metaphorphosis) extremely successful Insect flight mechanism Direct vs. indirect, involve 2 different setups in terms of how the thorax, flight muscles, and wings are arranged Direct muscles attached directly to wings (allows independent control of wings and rapid change in fligt direction and speed) Indirect flight muscles deform the thoracic box, leading to the movement of the wings as a consequence (more efficient because energy is conserved at several points) Different fly gropus fly at different wingbeat frequencies (5 Hz- butterfly to 1000 Hz- midge) Lower wing beat = synchronous, higher wing beat = asynchronous PART 4 Respiration Consist of cellular and external respiration Cellular = energy bound up in food is released, in mitochondria, glucose [O] = energy CO2 and H2O External respiration = supples O2, disposes CO2 Small organisms = gasses are exchanged via direct diffusion across cell membrane Evolution = increase size = metabolic rates = more complex respiratory systems suited for specific O2 requirement and the environment Aquatic animals must have efficient respiratory mechanisms (20% of energy for breathing) Larger animals have evolved speed surfaces for respiration (used to ventilate and dissolve gas to be transported across the body) 3 main types 1. Gills 2. Lungs 3. Trachea (transport gases) Respiratory pigment = increase in efficient of gas uptake ( haemoglobin) Circulation...
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