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46 Cards in this Set
- Front
- Back
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What are the defining features of bacteria?
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no nuclear envelope
circular chromosomes some organelles propeller-like flagella almost all unicellular some gene exchange: transduction, transformation, conjugation lipids: glycerol bonded to straight-chain fatty acids via ester linkage peptidoglycan cell wall one RNA polymerase |
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What are the defining features of archaea?
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no nuclear envelope
circular chromosomes no organelles spinning flagella all unicellular gene exchange: transduction, transformation, conjugation lipids: glycerol bonded to branched fatty acids via ether linkage no peptidoglycan in cell walls DNA polymerase similar to eukaryote |
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What are the defining features of eukarya?
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yes nuclear envelope
linear chromosome many organelles different flagella; mostly in reproductive cells most multicellular sexual reproduction in most species, some transduction and transformation lipids: glycerol bonded to straight-chain membrane fatty acids via ester linkage cellulose or chitin for cell wall complex RNA polymerases |
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What synapomorphies distinguish members of each domain?
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Bacteria: peptidoglycan cell wall
Archea & Eukarya: histones Archea: branched hydrocarbons in plasma Eukarya: linear chromosomes, nuclear membrane, multicellularity |
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In what types of environments would you expect to find archaea?
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In very extreme environments with harsh conditions
very salty water, hot springs, cow intestines, swamps |
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How are bacteria classified?
What features are typically used? |
Size, shape, motility
The shape of the bacteria could be spherical (coccus), rod (bacillus), spirochete, or vibrio (curved rod). Swimming. |
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What are Koch's postulates?
How are they related to the development of the germ theory of disease? |
-Four criteria must be met to link a disease with a microbe:
1. Microbe must be present in affected and absent from unaffected 2. Microbe must be isolated & grown in pure culture 3. If inject pure culture into healthy individual, disease will result 4. Must be able to culture microbe again from the newly infected individual The pattern component of this theory is that certain diseases are infectious, and the process responsible for this pattern is the transmission and growth of certain bacteria and viruses |
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How have bacteria caused global climate change?
Which group of bacteria has been primarily responsible for our current climate? What adaptations have allowed them to make these changes? |
Cyanobacteria changed heavy CO2 & methane concentrated environment to what we have today (early photosynthesis)
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What are some other important ecological roles of bacteria?
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Nitrogen fixation
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What are the main strategies by which organisms obtain energy and carbon?
What are the sources of each? |
photoautotroph, chemoautotroph, photoheterotroph, chemoheterotroph
light, organic compounds, or inorganic compounds |
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Are the protists a monophyletic group?
Why or why not? |
No, they are paraphyletic.
they represent some, but not all, of the descendants of a single common ancestor. |
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What characteristics are most commonly used to classify the protists?
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nuclear envelope, large, many organelles, multicellulartiy, mitosis, meiosis. All eukaryotes that are not green plants, fungi, or animals.
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What is the endosymbiotic theory?
What pieces of evidence support this theory? |
The endosymbiotic theory proposes that mitochondria originated when a bacterial cell took up residence inside a eukaryote about 2 billion years ago.
Mitochondria are about the size of proteobacterium Mitochondria replicate by fission Mitochondria have their own ribosomes Mitochondria have double membranes Mitochondria have their own genomes, which are circular |
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What is the difference between primary and secondary endosymbiosis?
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Primary: engulfing chloroplasts
Secondary: engulfing eukaryotic cell and retains chloroplasts |
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What are some important ecological roles of fungi?
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Only organisms besides some bacteria that can digest both the lignin and cellulose that make up wood.
Mutualists that benefit their hosts. Provide water and nitrogen and phosphorus for plant roots parasitic fungi grow on things saprophytic fungi decompose dead matter |
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What structures make up the body of fungi?
How are these structures adaptations to their environment conditions? |
The feeding structures of a fungus is a mycelium which is made up of hyphae. in some species, hyphae come together to form multicellular structures such as muchrooms, brackets, or morels that emerge from the ground. hyphae are often divided into cell-like compartments my partitions called septa, which are broken by pores. as a result the cytoplasm is continuous.
Large surface area = more absorption |
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What life cycle do fungi follow? What key features are present in this cycle?
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Plasmogamy = fusion of cytoplasm of two individuals
Asexual reproduction: mitosis Secual reproduction: plasmogamy -> karyogamy -> meiosis -> mitosis Zygote is only diploid cell (karyogamy-->meiosis) Chytridiomycete life cycle: make chytrid-like motile gametes and spores Zygomycota life cycle: makes zygote with tough outer coat Basidiomycota: makes pedestal-like basidium Ascomycota makes sac-like ascus |
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What features are most commonly used to classify the fungi?
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Fungi are classified based on spore-producing structures
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What are some important ecological roles of plants?
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Plants provide ecosystem services because they enhance the life-supporting attributes of the atmosphere, surface water, soil, and other physical components of an ecosystem:
plants produce oxygen plants build and hold soil plants hold water and moderate climate plants convert sunlight to chemical energy, and are key to the carbon cycle |
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What adaptations have allowed land plants to adapt to their environment?
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aquatic to terrestrial environments
out of water: waxy cuticle and stomata upright growth: vascular tissue and lignin water-transport: tracheids |
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What synapomorphies have been used to classify the different divisions of plants?
(Bryophytes, Pterophytes, Gymnosperms, Angiosperms) |
Bryophytes (non-vascular): land, cuticle, pores, stomata
Pterophytes (seedless vascular): vascular tissue, roots, tracheids Gymnosperms: seeds, pollen Angiosperms: flowers |
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What generalized life cycle do plants follow? What key features are present in this cycle?
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seed, seed distribution, germination, seedling, adult, pollen,
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How do plants obtain energy? Carbon? How is this energy used to fix carbon?
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Energy from sunlight
Carbon from CO2 in atmosphere |
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What are the 3 main organ systems in plants? What are the main functions of each? How have they been modified to perform specific functions in different environments?
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Roots, stems, leaves
Roots: water uptake, nutrient uptake, anchorage, storage Stem: support for light access and sexual reproduction, transport water and nutrients Leaves: photosynthesis Modified roots: prop roots, pneumatophores, storage roots Modified stems: cactus stems, stolons, rhizomes, tuber (potato), thorns Modified leaves: onion leaves, aloe vera stores water, pea tendrils climb, poinsettia attract pollinators, pitcher plant leaves trap insects, flowerpot leaves |
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What are the 3 plant tissue systems? What are the functions of each? How are they put together in each organ system?
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Dermal tissue, Vascular tissue, Ground tissue
Dermal tissue: (skin) protection from water loss, pathogens and herbivores, secretes waxy cuticle. stomata allow gas exchange, root hairs absorb water and nutrients. Vascular tissue: (tubes) transport substances: xylem: water and nutrients, phloem: sugars Ground tissue: (matrix) storage, photosynthesis, structural support eudicot: vascular bundles are in a ring monocot: vascular bundles are scattered throughout pith |
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What are the 3 plant cell types? How are they structurally different? How do these structural differences relate to the different functions of each cell type?
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Parenchyma, Collenchyma, Sclerenchyma
Parenchyma: generic plant cells. soft, thin primary walls, storage, photosynthesis, different pigments, metabolism Collenchyma: flexible support. thickened primary walls (no secondary walls) support growing plant, alive, flexible, (stringy part of celery) Sclerenchyma: rigid support. secondary cell walls, often lignified, dead at maturity, grittiness of a pear |
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What is primary growth? Where does it occur? What adult tissues are derived from the different meristematic tissues?
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Primary growth: apical meristems, roots and shoots elongate in all plants. procambiam -> primary vascular tissues, protoderm -> epidermis, ground meristem -> ground tissue
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What is secondary growth? Where does it occur? What distinguishes wood vs. bark? How do lateral meristems add new vascular tissue? In which direction? How does this growth provide a record of environmental conditions?
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Secondary growth: lateral meristems
Increase growth, only woody plants Cambium cells divide to increase girth Cork cambium produces outer bark, wood is secondary phloem and xylem vascular cambium stops growing during different parts of the year, showing the growth rings |
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How does water potential predict water movement? What is solute potential? Pressure potential? What creates each in plants?
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Low water concentration = low water potential
High water concentration = high water potential water flows from high -> low potential Solute potential = the tendency of water to move by osmosis, in response to differences in solute concentrations. Pressure potential = the tendency of water to move in response to pressure, created by turgor pressure on inside of cell. Water potential = solute potential + pressure potential |
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How does water potential (and flow) change in wet vs. dry environmental conditions?
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Solute potential in plant tissue drops in dry conditions and rises in wet conditions.
As soils dry, water potential declines, but if a plant's solute potential also drops, it can maintain a water-potential gradient that continues to bring water into the plant. |
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What drives water movement from soil to roots to vascular tissue to shoots? What 3 main hypotheses have been used to explain this flow? What evidence discounts or supports each of these?
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Hypotheses for passive movement:
1. Root pressure (pushed up from roots) -only pushes water about 1 yard, accounts for dew 2. Capillary action (thin tubes) -only pulls water about 1 yard 3. Cohesion-tension (pulled out stomata) -pull is created by evaporation. TRANSPIRATION. pull created by transpiration is transmitted down to roots by H-bonds |
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What is the trade-off between photosynthesis and water loss in plants? What is the cause of this trade-off? What are some adaptations that plants have made to a) limit this water loss and b) be able to maintain photosynthesis in arid environments?
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Conundrum:
needs CO2 from air to make food, maximize exposure to air to get CO2, air steals water, minimize exposure to air to save water. a) stomatal opening and closing b) thick cuticle, thick epidermis, stomata only on lower side of leaf |
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How do stomata open and close? (Movement of ions and water)
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low water potential due to high K+ causes water inflow and swelling = turgid (open)
stomata close when K+ exits, water potential lowers outside of cell, water flows out of guard cells = flacid (closed) |
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What makes up phloem sap? What structures does if flow through? What is a sugar source vs. sink? how is sugar loaded at the source? (know this process) What evidence supports this mechanism? What drives the bulk movement of phloem sap throughout the plant? Is the direction of this movement always the same? Why or why not? How is phloem sap unloaded at the sink?
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Phloem sap = 30% sugar, minerals, amino acids, hormones, water
Phloem sap flows from sugar sources to sinks (sources=leaves, sinks=flowers/fruit and roots) 1. active transport loads sugar into companion cell/sieve-tube member 2. low water potential at source 3. water flows in from xylem, creating pressure 4. pressure at source -> bulk flow to sink 5. sugar removal at sink |
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What substances make up a plant? Where do plants obtain the different nutrients they need to make these substances?
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Water = 80-85% wet weight
Carbohydrates & other organic compounds = 95% dry weight -cellulose (C, H, O) -proteins & DNA (also N, P, S) Inorganics = 5% dry weight |
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What are macro/micro/essential nutrients? How do we test for which nutrients are essential?
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macronutrients: Fundamental building blocks (C, H, O, P, S, K, N, Ca, Mg)
micronutrients: Trace catalysts- enzyme cofactors <0.01% of plant essential: required to complete lifecycle OR known component of specific structure Hydroponics test for symptoms of nutrient deficiency |
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What nutrients are mobile vs. non-mobile? Which nutrients are more likely to be mobile?
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Mobile nutrients: deficiency appears in older leaves
Non-mobile nutrients: deficiency appears in younger leaves |
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Why is fertilizer mostly N, P, and K?
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N: proteins (amino acids), N-bases of nucleic acids
P: sugar-phosphate backbone of nucleic acids, phospholipids for membrane, ATP K: regulates cellular water balance (Macronutrients obtained from soil) |
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How is soil created? Why is its texture and composition so important to the plants that grow in it? (Know the major properties of sand, clay, and humus)
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Weathering creates soil
Pores - air & water Nutrient availability Water storage Sand: low water availability, low nutrient availability, high oxygen availability, high root penetration Clay: high water availability, high nutrient availability, low oxygen availability, low root penetration Organic matter: high water availability, high nutrient availability, high oxygen availability, high root penetration |
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How do roots take up important nutrients? How does this process differ for cations vs anions?
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Most mineral uptake occurs through root hairs.
Roots exude acid to release nutrients Nutrients now available in solution Cations released through cation exchange Pumping out H+ creates electrochemical gradient Cations enter through channels along electrochemical gradient Specific anions enter through symporters against their electrochemical gradients |
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How does a plant prevent the import/transport of unwanted/toxic substances? Why are the endodermis/Casparian strip so important in this selectivity (relate to water transport?
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Absence of transport proteins in endodermis limits uptake of toxic/superabundant ions.
The presence of the Casparian strip allows endodermal cells to act as a selective filter preventing some ions from entering the symplast and reaching the xylem |
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What are some important symbiotic relationships and specialized adaptations that plants use to obtain limiting nutrients?
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Epiphytes (particle capture)- absorb nutrients through air, often grow on branches or leaves of trees
Parasites- make own sugars through photosynthesis and tap the xylem of other species for water and essential nutrients Carnivorous- make their own carbohydrates via photosynthesis but use carnivory to supplement the nitrogen available in the environment |
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What are some of the most commonly used applications of plant biotechnology? What new traits are plant genetic engineers trying to add to these plants? What are some of the potential benefits of these traits?
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-increase crop yields/profits
-stress-resistant plants -reduce environmental impacts of farming -nutritional enhancements -produce plants with new properties -bioremediation |
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What steps are needed to create a transgenic plant using recombinant DNA technology?
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Recombinant DNA Technology-
Must be able to: -Identify/clone the gene -Manipulate the gene -Express-DNA gene products |
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What are some potential effects of genetically modified crops on the environment? Are all of these effects necessarily environmentally damaging (might some be beneficial)? What are some mechanisms that plant genetic engineers and farmers are using to address environmental concerns?
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Pest resistance --> evolution of resistant pests & weeds
Risks to nontarget organisms Testing for risks |
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What are some potential effects of genetically modified crops on human health? Are all of these effects necessarily harmful? What are some steps that are taken to address these concerns?
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Allergies
More nutrients (golden rice) not all necessarily harmful Labeling "non-GMO" etc. |
