ECOL 182R Exam 1 Review PDF

ECOL 182R Exam 1 Review Theory An explanation of a natural phenomenon that can be supported by many observations. The same results happen over and over using the scientific method. Example is the Theory of Gravity Plants - Autotrophic - Eukaryotic - Multicellular - Generally adapted to l...

ECOL 182R Exam 1 Review Theory An explanation of a natural phenomenon that can be supported by many observations. The same results happen over and over using the scientific method. Example is the Theory of Gravity Plants - Autotrophic - Eukaryotic - Multicellular - Generally adapted to live on land (terrestrial) - Have a cell wall - Take in CO2 Animals - Heterotrophic - Eukaryotic - Multicellular - Take in oxygen - Specialized sensory organs Water on Earth 71% of Earth’s surface is water 97% of this water is salt water, 3% is freshwater Properties of water Polarity: Water is polar, so it dissolves more substances than any other liquid (Universal solvent) Cohesion: Water is “sticky” and creates surface tension Adhesion: Water sticks to other things, such as capillary action inside plants. Inside plants, water molecules pull each other up against gravity, osmosis passively absorbs water through the roots, and water evaporates through the stomata. Nutrients in different biomes 3 classes of soil: Clay, silt, sand Sand: greatest particle size = greatest room between particles Different biomes are challenging for different reasons Deserts have very little nutrient release Tropical forests have multiple soils (acidic) and soils are very nutrient poor. Adaptations to low nutrients Plants: Waxy leaves, root allocation, spines and hairs, carnivory Animals: Structural adaptations, resource adaptations, metabolic adaptations Photosynthesis Conversion of inorganic carbon dioxide into organic compounds using water and light energy Lecture 2 - Mechanisms of Evolution Natural selection: genetic variation among individuals in a population lead to some outcompeting others, parts of genes are passed down from generation that survives. Adaptations: inherited traits favored by natural selection. Evolution by natural selection requires: - Individuals in a population vary in some trait - At least some variation is genetically based - Certain genotypes produce more surviving offspring than others - Differences in survival among genotypes due to an agent of selection Other mechanisms Genetic drift → random chance Population bottleneck by chance Gene flow → transfer of alleles Mutation → alteration of a gene Lecture 3 - Speciation Population → all of the individuals of a species living within a specific area Species → a group of individuals that interbreed and are capable of producing viable offspring Isolation and Divergence Isolation then genetic divergence Allopatric (different countries) speciation→ Physical barrier Sympatric (same country) speciation → No physical barrier ○ Time (ex. Hawthorn fruit fly) Speciation is complete when the two populations can no longer interbreed and produce viable offspring. There is no longer any gene flow. Mechanisms of reproductive isolation 1. Prezygotic → before the zygote a. Allopatric barrier b. Sympatric barrier i. Behavioral isolation 2. Postzygotic → after the zygote formation a. Hybrid inviability i. Does not develop ii. Die before birth b. Hybrid sterility Lecture 4 - Phylogenies Domain → Genus → Species Nomenclature: Naming Organisms Binomial method 1. Genus → species 2. Specific epithet → second part (ex. Homo Sapien) 3. Authority → Scientist of group of scientist name Phylogenetic Tree Phylogenetic relationships Lecture 5- Plant Diversity Stem: Main support for the plant, holding leaves and branches Transports water and minerals Can be photosynthetic in some plants Stores materials Can be adapted for specialized functions in some plants Herbaceous Stems: Woody Stems: Soft, Green, Flexible Hard, secondary growth (wood) Dies to ground at the end of the season May go dormant at end of season Root Functions Anchor plant to its substrate Absorb water and minerals Produce hormones Leaf Photosynthesis: Harvest sunlight and capture CO2, chloroplasts make energy Minimize water loss: Moisture is lost because of CO2 intake, waxy surface and stomata used to prevent loss Transport water and sugar in veins: Xylem pulls water from roots, phloem cycles sugar to the rest of the plant as a vascular bundle Adapt to environment Flower Protects sexual organs Produces fruit Fruit functions as a seed dispersal tool Attracts pollinators Plants are pollinated to reproduce, pollinators do it freely Plant Cells Cellulose is the main component of the cell wall Plasmodesmata allows for communication between cells Vacuole has many functions Digestion, storage, defense, allows plant cells to be large without lots of cytoplasm required. Chloroplasts and Mitochondria Chloroplast is the site of photosynthesis, functions as a semi-autonomous organelle Mitochondria is the site of cellular respiration, also semi-autonomous. Converts chemical energy in sugar into ATP Plant life cycle: All land plants… Develop from an embryo, protected by tissues of parent plant Have multicellular, gamete producing structures Have protected, multicellular, spore-producing structures (sporangia) that produce spores Plant Evolution Land plants evolved once from ancestral green alga First plants were non-vascular (no xylem to cycle water or phloem to cycle sugar) First vascular plants were “ferns” and “fern allies”. No seeds, so reliant on water to reproduce. First seed plants are conifers. First plants that can do seed dispersal from water Key Characteristics of Plant groups Lecture 6: Plant Adaptations Challenges to life on land for plants Water provides a lot of resources for plants Adaptations of Land Plants Plant body: obtaining resources, maintaining moisture, and staying upright Symbiosis with fungi (mycorrhizae) Mycorrhizae provides water and nutrients via hyphae Plant provides sugars from photosynthesis Multicellular with specialized functions Waterproofing Stem support Root systems Leaf Morphology There is a large diversity in leaves, but all leaves should not: Lose too much water Allow pathogens in Be too delicious Act like a sail Be too costly to make Leaf Functions Photosynthesize (Capture light and CO2) Minimize water loss (Guard cells and cuticle) Transport water and sugar (Vascular bundle in leaf veins) Adapt to environment (Stomatal crypt) Waterproofing Common theme of land plants is to reduce dependence on water. Oldest plants had no true roots, stomata or seeds. Later land plants could disperse farther from water Vascular tissues, guard cells, seeds all helped with this. Stem Adaptations Not all plants have woody growth, only present in seed plants Wood originated in gymnosperms and angiosperms Woody tissue present in stems and roots Not all plants have vascular tissues Rhizoids only anchor (not true roots) Vascular tissues are important to cycle water and nutrients, originated in ferns Mitosis vs Meiosis Major Types of Sexual Life Cycles Haploid Dominant: Multicellular, haploid stage is the most obvious Alternation of Generations: Haploid and diploid stages are both multicellular and both dominate at some point. Multicellular structures develop to protect the reproductive structures Aided the transition to life on land Plants and some algae have an “alternation of generations”