BIOL 1108 Lecture Notes - Lecture 6: Cell Adhesion, Multicellular Organism, Genetic Programming
24 Oct 2018
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Complex multicellularity arose several times in evolution. Complex multicellularity depends on cell adhesion, communication, and a genetic. In complex multicellular organisms, bulk flow circumvents the limitations of diffusion. program for development. Plants and animals evolved complex multicellularity independent of each other, and solved similar problems with different sets of genes. The evolution of large and complex multicellular organisms, which required abundant oxygen, is recorded by fossils. Simple multicellularity: the 36 remaining groups have at least simple multicellularity. Form is filamentous, hollow balls or flat sheets. Most cells retain a full range of functions. All cells are still in contact with environment. Surface area to volume (sa/v): stolen from wikipedia. Sa:v of cells (and organisms) has enormous impact on biology. Ex. many aquatic microorganisms have increased sa to increase drag. This reduces rate of sinking and allows them to float with less energy expenditure. An increased surface area to volume ratio also increases exposure to the environment.
