BIOL208 Lecture Notes - Lecture 10: Food Quality, Wu Xing, Heterotroph
11 Oct 2018
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Lecture 10 energy acquisition heterotrophs: herbivores- organisms that eat plants, carnivores- organisms that eat animals, detritivores- organisms that eat already non-living (dead) organic matter (been dead for a while, food quality: Five elements make up 93- 97% of biomass of plants, animals, fungi and bacteria. Low n concentrations but high carbon content, overcome plant physical (cellulose and lignin) and chemical defences (toxins and digestion reducing compounds) C:n ratio lower for needles and leaves than woody tissue- hence they have more nutritional value. Strong mouthparts for repeated chewing and crushing seeds. Large number of microbial symbionts (digest cellulose: carnivory: hunting requires a lot of energy and has low success rate, high nitrogen content of food. Little variation in c:n variation in foods hence many prey species available to single carnivore. Food quality is low, poor in nitrogen, nitrogen supply is low to plants so plants have nitrogen use efficiency (nue) so they absorb n before dropping leaves.
