BIO 2135 Lecture Notes - Lecture 11: Osmoregulation, Hydrostatic Skeleton, Sensillum
14 Feb 2017
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Document Summary
No musculature to push the food through the digestive tract relies on body movements. Originally, people couldn"t figure out how it arose. Acoelomates all specialize in miniaturization get smaller and smaller use minimal numbers of cells to the point where there is a critical number. Some organisms in this group crawl in the water in between sand grains. Moutled protein cuticle reinforced with alpha chitin or collagen. No surface cilia (non living layer causes it to disappear) Loss of the coelom replace it with fluid that bathes the organs. Pair of amphids contain sensory cells, used to sample environment in which they are living. Epitheliomuscular pharynx no mesoderm in gut. Three circumoral rings with 6, 6, 4 sensilla in the rings. May seem to be radially symmetric from the mouth roundworms . Use whiplike motion to get around in water.
