Final Exam Notes PDF

Sure, here are notes on the topics you requested: Unit 1: Plant Fundamentals Seeds: ○ Plant biology's essential role: Seeds contain nutrition for the embryo, facilitate germination, and play a crucial role in plant reproduction. ○ Basic structure and functio...

Sure, here are notes on the topics you requested: Unit 1: Plant Fundamentals Seeds: ○ Plant biology's essential role: Seeds contain nutrition for the embryo, facilitate germination, and play a crucial role in plant reproduction. ○ Basic structure and function: Seeds consist of an embryo, endosperm (or cotyledons), and a seed coat. The embryo develops into a new plant, while the endosperm provides nourishment. Germination occurs when environmental conditions are favorable, triggering the embryo to grow. ○ Factors preventing germination: Seeds may remain dormant due to unfavorable conditions like temperature, moisture, or light. Classification: ○ Current system: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. ○ Evolutionary limitations: This system doesn't always accurately reflect evolutionary relationships. ○ Evolutionary tree diagrams: Practice identifying major groups and key characteristics by analyzing evolutionary tree diagrams. Latin Binomial: ○ Scientific name format: Genus (capitalized) followed by species (lowercase). ○ Example: Homo sapiens (human) Cyanobacteria:  ○ Essential organisms: Photosynthetic bacteria, vital for ecological balance and evolution. ○ Autotrophs and heterotrophs: Autotrophs produce their own food, while heterotrophs consume other organisms. Cyanobacteria are autotrophs. ○ Endosymbiosis: The process by which cyanobacteria were engulfed by larger cells, leading to the evolution of chloroplasts in plants. ○ Connection to green algae and land plants: Cyanobacteria are ancestors of green algae, which eventually evolved into land plants. Plant Evolution: ○ Key features of land plants: Developed as plants adapted to life on land, including features like roots, stems, leaves, vascular tissue, and cuticles. ○ Importance of these features: Roots anchor plants, stems provide support and transport, leaves capture sunlight, vascular tissue transports water and nutrients, and cuticles reduce water loss. Life Cycles: ○ Major plant groups: Mosses, ferns, seed plants, and flowering plants. ○ Differences and similarities: Life cycles vary in the dominance of gametophyte (haploid) and sporophyte (diploid) generations. Spores and seeds differ in structure and function. Flowers, fruits, and seeds are unique to seed plants. ○ Fertilization and meiosis: Fertilization occurs when a sperm cell unites with an egg cell. Meiosis produces haploid gametes (spores or gametes).  ○ Double fertilization in angiosperms: A unique process in flowering plants where a sperm cell fertilizes both an egg cell and a polar nucleus, leading to the formation of the zygote and endosperm. Flower Parts: ○ Know the names and functions of major flower parts, such as sepals, petals, stamens (anthers and filaments), and pistils (stigma, style, and ovary). Angiosperm Families: ○ Learn the names, key characteristics, and important crop members of nine major angiosperm families. ○ Consider which family is most important for feeding the human race and why. Unit 2: Plants and People Crop Domestication: ○ Process of domestication: Selecting plants with desirable traits and cultivating them over generations. ○ Timeline: Domestication began around 10,000 years ago. ○ Major domesticated crops: Wheat, rice, maize, potatoes, tomatoes, beans, etc. ○ Selected traits: Larger fruits, seeds, or roots; less bitter taste; easier harvesting; disease resistance. ○ Biological basis of traits: Traits are determined by genes, which are segments of DNA that code for proteins.  Balter Publication on Crop Domestication: ○ Significance of wheat spikelets: The shape of wheat spikelets (rough or smooth) indicated whether they were wild or domesticated. ○ Changes over time: Spikelets became smoother as humans selected for easier harvesting. ○ New findings: The publication suggested earlier domestication in the Americas than previously thought. ○ Hypotheses for the rise of agriculture: Climate change and societal development may have both played a role. Mutations: ○ Ultimate source of genetic variation: Mutations are random changes in DNA that can create new alleles (alternative forms of a gene). ○ Not always impactful: Most mutations have no effect or are harmful. Beneficial mutations can be selected for through natural or artificial selection. John Chapman & Apple Orchards: ○ Apple propagation: Apples grown from seeds do not produce the same fruit as the parent tree due to genetic variation. Grafting is used to preserve desired traits. ○ Modern orchard operations: Focus on efficiency and uniformity, often using clonal propagation. ○ Changing relationship with apples: Apples have become more widely available and diverse in varieties. Meristems:  ○ Plant growth centers: Meristems are regions of actively dividing cells responsible for plant growth. ○ Stem cells: Meristem cells are stem cells, capable of differentiating into various cell types. ○ Types of meristems: Shoot apical meristem (SAM) and root apical meristem (RAM) are responsible for primary growth (lengthening). The vascular cambium is responsible for secondary growth (widening). ○ Grafting: Meristems are used in grafting to join two different plants. Sexual Reproduction & Meiosis: ○ Genetic variation: Sexual reproduction increases genetic variation through the mixing of genes during meiosis. ○ Apple pollination: Apples are self-incompatible, requiring pollen from another tree for fertilization. ○ Chromosomes and meiosis: Chromosomes are thread-like structures that contain DNA. Meiosis, a specialized form of cell division, results in the production of haploid gametes with unique combinations of chromosomes due to crossing over and independent assortment. Stomata & Water Transport: ○ Water movement in plants: Water enters plants through roots and is transported upward through the xylem vessels to leaves. ○ Stomata: Pores on the leaves that regulate water loss and gas exchange. ○ Turgor pressure: The pressure exerted by water within plant cells, maintaining their rigidity.  ○ Cohesion-tension model: Explains how water is pulled up the xylem due to cohesion between water molecules and tension created by transpiration. ○ Root water uptake: Roots absorb water and minerals through osmosis and active transport. ○ Endodermis and Casparian strip: The endodermis is a layer of cells in the root that regulates water and ion uptake. The Casparian strip is a waterproof band that surrounds the endodermal cells, preventing water from entering the root apoplastically. Soils: ○ Composition: Soils consist of a mixture of minerals, organic matter, water, and air. ○ Organic matter benefits: Improves soil structure, water retention, nutrient availability, and microbial activity. ○ Clay: Fine-grained soil particles that hold water and nutrients but can be compacted. ○ Loam: Ideal soil composition with balanced amounts of sand, silt, and clay. ○ Air space: Essential for root respiration and oxygen availability. ○ Cation exchange: The process by which soil particles exchange cations (positively charged ions) with plant roots, providing nutrients. ○ Acidic soils: Nutrient-poor due to low availability of essential nutrients. Can be improved by adding lime to raise pH. Nitrogen & Carbon in Soils:  ○ Nitrogen: Essential nutrient for plant growth, obtained from the atmosphere or soil. ○ Haber-Bosch process: Industrial process for producing nitrogen fertilizer from atmospheric nitrogen. ○ Regenerative agriculture and carbon farming: Practices that aim to improve soil health, increase carbon sequestration, and reduce environmental impact. Unit 3: Deep Dive Photosynthesis & Respiration: ○ Photosynthesis: Process by which plants convert light energy into chemical energy (glucose). ○ Respiration: Process by which cells break down glucose to produce ATP, the energy currency of the cell. ○ Interconnectedness: Photosynthesis and respiration are interconnected, as photosynthesis provides the glucose used in respiration. Photosynthesis in depth: ○ Light-dependent reactions: Convert light energy into ATP and NADPH. ○ Carbon fixation reactions (Calvin cycle): Use ATP and NADPH to fix carbon dioxide into glucose. ○ Pigments: Chlorophyll and other pigments absorb light energy. ○ Electron transport chain (ETC): Transfers electrons from excited chlorophyll to produce ATP.  ○ ATP synthase: Enzyme that uses the proton gradient generated by the ETC to produce ATP. ○ RUBISCO: Enzyme that catalyzes the initial step of carbon fixation. ○ C3 photosynthesis: The most common type of photosynthesis, named for the three-carbon compounds produced in the first step of carbon fixation. GMO Discussion: ○ GMOs (Genetically Modified Organisms): Organisms whose DNA has been altered through genetic engineering. ○ Debate: GMOs have potential benefits but also raise concerns about safety, environmental impact, and ethical implications. ○ Selective breeding: Traditional method of improving crops through artificial selection. ○ Glyphosate-resistant crops: Crops engineered to be resistant to the herbicide glyphosate, leading to the emergence of glyphosate-resistant weeds. ○ Bt crops: Crops genetically modified to produce Bacillus thuringiensis (Bt) toxin, which kills insect larvae like caterpillars. Gene Editing: ○ Precise modifications: Makes targeted changes to specific DNA sequences. ○ No foreign DNA: Typically does not introduce foreign DNA into the organism. ○ Examples: CRISPR-Cas9  ○ Often considered less drastic: Changes may be similar to naturally occurring variations. Genetic Engineering: ○ Broader term: Includes techniques like gene editing, but also encompasses the insertion of foreign DNA from other organisms. ○ May introduce foreign DNA: Can involve transferring genes from one organism to another. ○ Examples: Creating GMOs (Genetically Modified Organisms) by inserting genes for herbicide resistance or pest resistance. ○ Can create novel traits: Allows for the introduction of traits not found in the original organism. C4 Photosynthesis: ○ Adaptation to hot and dry environments: C4 photosynthesis is more efficient in hot and dry conditions by concentrating CO2 around RUBISCO, reducing photorespiration. ○ Process: C4 plants initially fix CO2 into four-carbon compounds, which are then transported to specialized cells where CO2 is released for use in the Calvin cycle. ○ Potential benefits of engineering C4 photosynthesis into C3 crops: Could improve crop yields and water use efficiency in challenging environments. ○ Examples: Corn, sugarcane, sorghum, millet, etc. C3 Photosynthesis: ○ Most common type: Found in most plants.  ○ Initial carbon fixation: CO2 is directly fixed by RUBISCO into 3-phosphoglycerate (a 3-carbon compound). ○ Photorespiration: RUBISCO can also bind to oxygen, leading to a wasteful process called photorespiration, especially under hot and dry conditions. ○ Less efficient in hot and dry conditions: High temperatures and low CO2 levels can increase photorespiration, reducing photosynthetic efficiency. ○ Examples: Wheat, rice, soybeans, etc. Key Themes: Plant Evolution: Understanding the evolutionary history of plants, including the development of key features and the diversification of plant groups. Life Cycles: Understanding the different life cycles of plants and the importance of reproduction in plant survival. Photosynthesis: Understanding the process of photosynthesis, its importance for plant growth and global carbon cycling, and the adaptations that have evolved to improve photosynthetic efficiency. Plant-Human Interactions: Exploring the history of plant domestication, the impact of agriculture on human civilization, and the challenges and opportunities presented by modern agricultural practices. Genetic Variation: Understanding the sources of genetic variation in plants and its importance for adaptation and crop improvement. Soil Science: Recognizing the importance of healthy soils for plant growth and sustainable agriculture.