BIOL 152 9thEdition Lecture 11 Outline of Last Lecture I Archaea and Bacteria are Fundamentally Different II Oxygen III Working Together Metabolic Cooperation IV Slime Molds Blurring the Lines V Cellular Slime Molds Outline of Current Lecture I Why Become Multicellular Part 2 II Multicellularity III Plants vs Animals IV General Requirements Current Lecture 1 Multicellularity is defined in part by the presence of distinct cell types What does this mean a Different cell types express different genes I Why Become Multicellular Advantages o Can get more nutrients o Reproduction o More support o Can avoid predators protection structural protection Challenges o Requires more energy o Adhesion o Diffusion Size Concentration Distance Media air water Structural Changes needed Part 2 These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute I Multicellularity Meaning complex Evolved independently several times at least 6x Includes animals plants algae and fungi Unicellular Simple Multicellular Multicellular Evolution of multicellularity required o Communication between cells o Different genes Diffusion o One of the last things needed to overcome 1 Cell Adhesion o Stick together o Accomplished how exaptation o Originally used for in the unicellular cousins o How Depends on organism Animals transmembrane proteins o Cadherins o Integrins Plants polysaccharide o Pectins Originally used for o Choanoflagellates Have same genes that make cadherin and integrin May use to hypotheses Stick to substrates Help capture food bacteria Simple multicellularity induced b detection of food 2 Communicate o How Molecular signals Cellular adaptation Animals gap junctions gaps that connect animal cells Plants plasmodesmata gaps that connect plant cells o Originally Used For Predator detection Food Environment temp salinity pH oxygen content Sexual reproduction 3 Cell Differentiation gene regulation o Genetic program to guide cell division differentiation o How Developmental Biology Depends on which genes are turned on or off and when as cells replicate Genes signaling and regulation Ultimately controlled by environmental conditions o Common themes Genes regulated differentiation over TIME o 3 D differentiation must be regulated over SPACE Unicellular regulate in TIME mostly Evolution of multicellularity added regulation in SPACE II Plants vs Animals Differences inform how multicellularity is achieved o Plant cell wall o Animal no cell wall III General Requirements o Timing is everything