LIFESCI 1 Lecture Notes - Lecture 7: Blastula, Selective Breeding, Meristem
Document Summary
From unicellular to simple multicellular to complex multicellular. Evolutionary transition from being single celled to multicellular organisms. Have to be able to stick together in some way. Little communication: transfer of resources from one cell to another. Advantages: larger organism, so less available as food to other organisms; attached to one position. Many stages of mitosis, but last stage doesn"t work, so no division many nuclei in one cell. Seen in slime molds, algae, and in fungus. Red algae, green algae, brown algae examples of complex multicellularity. More developed mechanisms for adhesion and communication between cells. Cell differentiation into different tissue types and organ systems. Small subset of organism is responsible for reproduction. Organism most likely to die if loses one portion, unlike simple multicellular organisms. 3-dimensional: internal cells have access to completely different environment compared to outer cells. Development of bulk transport: developed circulatory system in animals, more extensive vacuole system in plants.
