BIOL 2030 Lecture Notes - Lecture 4: Pseudopodia, Wave, Ford Power Stroke Engine

• School: York University
• Department: Biology
• Course: BIOL 2030
• Professor: Andrew Donini

Document Summary

Topic 1: outline unicellular eukaryotes (protozoa/protista) [chapter 5] Introduction: locomotion, nutrition, digestion & excretion, osmoregulation. A cilium propels water parallel to the surface of the attachment: provides the (cid:373)ea(cid:374)s for (cid:862)directed(cid:863) (cid:373)ove(cid:373)e(cid:374)t, prevents stagnant layer of water accumulating around body. Ciliary beating: a circular motion with 2 components: power stroke: stiffened cilia propel water parallel to cell surface, recovery stroke: cilia bends towards body to reduce resistance. Body of cilia covered by distinct rows of cilia. Movement of organism is achieved by coordinating beating of cilia: metachronal beating movements produce the appearance of a travelling wave. Cilia beat can reverse permitting avoidance reaction. Cilia beat obliquely (i. e. at an angle), therefore organism moves in a spiral path. Sessile do(cid:374)"t (cid:373)ove arou(cid:374)d, a(cid:374)chored i(cid:374) o(cid:374)e locatio(cid:374) Moves water across cell surface i. e. prevents stagnation. Brings food particles towards the organism: pulsellum a flagellum that propels the cell in a cell body first direction. Moves organism through water like a tadpole.