BSC 121 Final Exam Review Questions And Correct Detailed Answers

nutrient - Correct Answers substance metabolized by or incorporated into an organism deficiency symptoms - Correct Answers develop in plants that receive to little of a nutrient what does scarcity of nutrients cause? - Correct Answers adaptations that help in acquiring nutrients essential nutrients - Correct Answers substances that a plant needs to complete the reproductive cycle macronutrients - Correct Answersl arge amounts required by plant nitrogen, potassium, calcium, mangensium, phosphorus and sulphur NPPCMS micronutrients/trace elements - Correct Answerssmaller amount required by plant limiting factors - Correct Answerscan limit growth -light -carbon dioxide -water -other mineral nutrients light - Correct Answersall photosynthetic plants require it essential resource helps form covalent bonds analogous to animals dependency on food deprived plants display deficiency symptoms chemical energy adaptations to shade - Correct Answerstranslucent thin leaves that allow light to pass through produce more chlorophyl sun and shade leaves epidermal cells shaped like lenses leaf arrangement and stem branching (tall tree leaves in forest, shady plants at forest bed) shade leaves - Correct Answersthinner mesophyll with more air spaces sun leaves - Correct Answersthicker layer of mesophyll with better ability to harvest sunlight adaptations to excessive light - Correct Answerschloroplasts can change position Xanthophyll and caratenoid pigments can absorb light energy and dissipate it as heat UV can be absorbed by cuticle, carotenoid and flavenoid compounds caratenoid - Correct Answersin leaf cells, adaptation for excessive light, gives leaves red or purple colors dangers of too much light - Correct Answerscan destroy essential photosynthetic protein (D1) in chloroplast where does most plant dry mass originate from - Correct AnswersCO2 absorbed from the atmosphere through stomata (pores in plant epidermis) photosynthetic rates - Correct Answersincrease with CO2 concentration until the calvin cycle enzyme rubisco has become fully saturated with CO2 hot and dry conditions make plants vulnerable to what? - Correct Answerslow CO2 levels when their stomata closes to conserve water (when stomata is closed, plants can't absorb CO2) thus limiting photosynthesis what substance can plants often not obtain enough of - Correct AnswersCO2 0.039 % of atmosphere many plants have adaptations that improve CO2 production what happens in greenhouses with air enriched with CO2 - Correct Answerscrops can double their growth rate water as an essential nutrient - Correct Answerssource of organic compounds (hydrogen and oxygen) solvent transporter (allows movement of minerals and other solutes throughtout the plant via vascular tissue) cytoplasmic/vacuolar water helps hydrostatic pressure--support 90% of plant weight most plants die when water content is below 45% metabolism and growth 3 major nutrients - Correct AnswersNPK nitrogen (can't be used as gas, converted to nitrate) phosphorus (used the quickest) potassium chlorosis - Correct Answersiron deficiency- yellow leaves deficiency symptoms - Correct Answerswhen plants lack essential nutrients failure to reproduce tissue death changes in leaf color soil horizons - Correct Answerslayers in natural soil topsoil, subsoil, soil base, bedrock differ in aeration, water capacity, pH mineral content, composition, thickness (depends on enviro. and human impact) soil nutrients come from activities of microorganisms what transports brings minerals up through the soil to the surface - Correct Answersroots what is used to classify soils - Correct Answersparticle size and proportion of organic and inorganic material humus - Correct Answersorganic constituents of soil derived from plant detritus, (animal waste and decaying animal bodies) humus poor - Correct Answerslittle organic material tropical rainforst (1%) humus rich - Correct Answersmore organic material cultivated farm land best for optimal growth (8%) less likely to erode fertile and easy to cultivate, high plant root growth soil comes from the ___________ of rock - Correct Answersweathering (physical and chemical breakdown of rock) leaching - Correct Answersdissolution and removal of inorganic ions as water percolates through heavy rainfall can reduce fertility by leaching large amounts of nutrients inorganic soil particles - Correct Answerscan be categorized by size how are soils classified - Correct Answersby amounts of coarse and fine materials sandy, silty, clay, loam soils sandy soils (porous) - Correct Answersallow air and water movement well aerated which helps roots get oxygen for cellular respiration water flows fast which reduces availability to roots and leaching out materials silts and clay soils - Correct Answersless porous particles fit tightly together water percolates less easily and more ionic nutrients are retained cation exchange cation exchange - Correct AnswersH+ replaces mineral cations on the surface of humus or clay particle -releases cations to soil water and plants -free ions can be washed away -acid rain adds H+ to the soil, which reduces soil fertility and pollutes streams loam - Correct Answerssand and clay preferable for agriculture b/c of combined aeration and mineral/water retention capacity fertilizers - Correct Answerscompensate for deficiencies in soil humus or mineral content to improve soil fertility organic fertilizer - Correct Answersmost mineral bound to organic molecules and released slowly (manure and compost) inorganic fertilizer - Correct Answersinorganic minerals are immediately useful but can be leached away can be harmful if washed away to other enviros. or plants fixed nitrogen - Correct Answersplants can't use atmospheric N2 gas, must get it in combined form use nitrate or ammonia (nitrate most common) microorganisms oxidize ammonia to nitrate stored in vacuoles transported in xylem what imports nitrate into root cells - Correct Answersplasma membrane transporter proteins where does most fixed nitrogen in soil come from - Correct Answersrecycled compounds in other organisms espensive process how can new fixed nitrogen be added - Correct Answerslightning, fire, air pollution, biological and industrial fixation (produces fertilizers for crops) nitrogen fixation - Correct AnswersN2 combined with H makes NH3 most done by prokaryotes biological nitrogen fixation - Correct Answersby cyanobacteria symbionts transfer nitrogen directly to plant cells prokaryotic organisms excrete substantial amounts of fixed nitrogen and their death makes even more available NH4 ammonium what do all nitrogen-fixing prokaryotes utilize to fix nitrogen? - Correct Answerslarge amounts of ATP and nitrogenase 16 ATP for every fixed nitrogen molecule industrial nitrogen fixation - Correct Answersin fertilizers produced from nitrogen gas reduction of N2 to NH3 high energy required genetically engineering nitrogen fixation into plants