LS1 Midterm 2 Study GuideChpt. 26 – Bacteria and Archaea (Prokaryotes)- Sulfur is cycled through assimilation (in plants and bacteria; organic sulfur in protein; SH), decomposition (in fungi and bacteria; product is H2S), and energy acquisition (chemosynthetic bacteria and photosynthetic bacteria; oxidation takes place of S; produces SO4)/anaerobic respiration (can come before/in place of assimilation; bacteria; skips decomposition; produces H2S). Not atmospheric.- Nitrogen is cycled through a bunch of shit (Fixation, ammonification, nitrification, dentrification, biosynthesis). NH3 can go wherever it wants; used multiple ways; necessary for the Earth. - Nitrogen fixation (N2 -> NH4+) is essential because N is required to biosynthesize basic building blocks of life forms; diazotrophs; N-fixing bacteria will likely outnumber the bacteria that are not capable of fixing N- Dentrification returns nitrogen to the atmosphere in the form of nitrogen gas; because of this, nitrogen fixation must continuously make nitrogen available to living organisms- In a microbial mat, the aerobic layer is at the top and anaerobic is at the bottom- Archaea lack a nucleus and form a second prokaryotic domain distinct from bacteria; both obtain energy from fermentation- Archaea thrive where energy for growth is limited; grow in highly acidic waters; tolerate high-salt conditions- Stromatolites are layered structures that record sediment accumulation by microbial communities (like tree ring thingys)Chpt. 27 – Eukaryotic Cells- Eukaryotic cells have a nucleus and are found in animals, plants, fungi, and insects.- There’s an alternation between sexual and asexual life cycles. Also an alternation in the haploid (prominent haploid phase has asexual mitosis after meiosis) and diploid (prominent diploid phase has mitosis before meiosis) cell cycles. Sexual reproduction has an advantage because it canproduce new genotypes and produces variation- Endosymbiosis is the idea that organelles of eukaryotes originated as symbiosis between separate single-celled organisms; mitochondria andchloroplasts evolved from cyanobacteria; eukaryotes acquired photosynthesis multiple times by repeated endosymbiosis- The 7 superkingdoms are: opisthokonta (most diverse group; animals and fungi; choanoflagilates; heterotrophic), amoebozoans (slime molds; plasmodial = coenocytic/one cell with multiple nuclei; cellular = feed on soil bacteria/unicellular), archaeplastida (contain chlorophyll A; green and red algae; can develop to land plants), stramenopiles (brown algae; have cells that are hairy and smooth; leaves a fossil record), alveolata (ciliates; apicomplexans; dinoflagellates; smooth cell walls; bioluminescence), rhizaria (shelled ameobae; foraminifera; radiolaria), and excavata (free-living; parasitic; symbiotic; euglenids). All contain protists (all protists have a nucleus; not an animal, plant or fungi).Chpt. 28 – Being Multicellular- Multicellularity is a synapomorphy (shared among 2 or more taxa) of the protists; synapomorphy is best described as a trait common in a single monophyletic group but not generally found outside that group- Simple multicellularity has cell adhesion, little communication or transfer ofrecources between cells, every cell is in contact with the external environment, most cells have all functions, and they are sheet-like and have 2 layers of cells; they avoid protozoan predators, maintain better position on surface of water; nuclei divide but no cytokinesis - Complex multicellularity evolved 6 separate times: animals, fungi (twice), red algae, green algae (plants), and brown algae; highly developed mechanisms for adhesion between cells, specialized structures for cell communication, tissue and organ differentiation, and the presence of both interior and exterior cells; the order in which the cells evolved is cell adhesion molecules, a mechanism of communication, and bulk transport capability; increase in atmospheric oxygen led to complex multicellularity; cells must stick together, communicate with one another, and participate ina network of genetic interactions for cell division and differentiationChpt. 29 – Plant Structure; Chpt. 30 – Plant Reproduction; Chpt. 31 – Plant Growth And Development; Chpt. 32, Sect 2 – Defense Against Herbivores; Chpt. 33 – Plant Diversity- Human use of plants: aesthetically pleasing, agriculture, fuel sources, forestry, bio-prospecting; ecological roles: produce oxygen, contribute tosoil, protect against erosion, buffer local climate, provide habitat, provide food- Photoautotrophs produce their own carbon energy source using sunlight (photosynthesis); “fix” carbon (inorganic C -> organic C)- Three types of terrestrial plants: nonvascular plants (do not have vascular tissues to conduct water and provide support; mosses), seedless vascular plants (have vascular tissues, but cannot make seeds; ferns), and seed plants (have vascular tissues and can make seeds; flowering plants/angiosperms).- Adaptations to avoid desiccation: waxy cuticle and stomata, CO2 uptake inleaves, CAM photosynthesis, guard cells- Evolutionary trend: gametophyte dominant to sporophyte dominant; water to land transition increased H2O dependence - Mosses: gametophyte dominant, H2O dependent for fertilization, dispurse via spores- Lycophytes: water fertilization, air dispersal, coal deposits- Ferns: 40% are epiphytic (growing on other things); vascular system is sporophyte dominant; H2O dependent for fertilization; disperse via spores- Gymnosperms: air pollinated, air dispersal; cycads and ginkos; conifers: pines, junipers, redwoods; lifecycle: pollination, fertilization, seed dispersal, germination, meiosis; sporophyte dominant (wind dispersal); pollen is H2O independent for fertilization; disperse via seeds; reduces competition for nutrient supply- Angiosperms: flowers; fertilized ovules become seeds; sporophyte dominant; asexual reproduction- Pollination via animals; pollen, nectar, trickery; fruit enhances pollination- Defense against herbivores: mechanical defenses (spikes, toughness); chemical (bitter taste, affects development, reduced digestibility); ecological (symbiosis of ants and acacia) Chpt. 34 – Fungi - Fungal Phrenology: Chitin walls; hyphae; regularly placed septa; complex multicellular fruiting bodies- Chitin is a polyaccharide that gives strength to the cell walls; structural support for moving through dirt- Fungi move via growth; extension of hyphae;