PPT

• All animals need to exchange substances with the environment.
• Diffusion is a process by which substances move from an area of high concentration to an area of low concentration.
• Surface area is the area of a cell's outer boundary.
• The difference in concentration is the difference in concentration between two areas.
• Distance is the distance between two areas.
• Surface area to volume ratio is the ratio of surface area to volume.
• Bacteria have a surface area to volume ratio of 6,000,000/m.
• Whale have a surface area to volume ratio of 0.06/m.
• The maximum size limit of a single cell is the maximum size limit of a single cell.
• All organisms larger than the size limit are multicellular.
• Surface area to volume ratio gets smaller as the cell gets larger.
• Solving the surface area to volume problem involves avoidance, geometric solutions, increasing surface area, decreasing effective volume, increasing rate of supply, high concentration of nutrients, improving nutrient transport within, improving efficiency to reduce demand, division of labor within the cell, and division of labor between cells.
• Multicellularity has evolved many times in eukaryotes.
• The Symbiotic Theory suggests that different species are involved in multicellularity.
• The Syncytial Theory suggests that ciliates and slime molds commonly occur in multinucleated cells.
• The classification of living things includes Archaea, Bacteria, and Eukarya.
• The Colonial Theory, proposed by Haeckel in 1874, suggests that the same species are involved in multicellularity.
• Phylogenetic trees provide important information about similar characteristics in closely related species.
• Green algae (Chlorophyta) have over 7000 species.
• Species in the Canidae family include Canis lupus, Canis latrans, and Taxidea taxus.
• The Volvocine model includes species such as Chlamydomonas, Gonium, Pandorina, Eudorina, and Volvox.
• Species in the Felidae family include Pantherapardus and Felis catus.
• Gonium is a unicellular flagellate that reproduces through isogamy.
• Species in the Mustelidae family include Mustela nivalis and Mustela erminea.
• Pandorina is a colonial organism with 8, 16, or 32 cells in one layer, spherical in shape, and reproduces through isogamy.
• Species in the Lutra lutra and Taxidea taxus families are also included in the Canidae, Felidae, and Mustelidae families respectively.
• Eudorina has 16 or 32 cells, with 16 cells not specialized and 32 cells divided into 4 for motility and the rest for reproduction, and reproduces through heterogamy.
• Species in the Carnivora, Felidae, and Mustelidae families are all members of the Canidae, Felidae, and Mustelidae families respectively.
• Pleodorina has 32 to 128 cells, with division of labor between vegetative and reproductive cells, and reproduces through heterogamy.
• Species in the Canis, Lutra, and Taxidea genera are also included in the Canidae, Felidae, and Mustelidae families respectively.
• Volvox has spherical colonies (500-50000 cells), with cell differentiation into somatic/vegetative cells and gonidia, and reproduces through intercellular communication.
• Anisogamy, or anisogamy/heterogamy, is a transition from isogamy to oogamy.
• Advantages of multicellularity include increase in size of the organism, increase in surface area to volume ratio, and increase in cell specialization.
• Problems of multicellularity include interdependence and complexity.
• Chromatin - DNA, RNA, proteins
• The nucleus is the control center of the cell.
• Ribosomes - protein synthesis
• Kingdoms & Domains: Chapter 18-3
• As we discovered more about the natural world, not all organisms fit into Linnaeus’s 2 kingdoms.
• Examples of organisms that don't fit into Linnaeus’s 2 kingdoms include bacteria, fungi, plant, and animal.