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105 Cards in this Set
- Front
- Back
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Define Botany
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The study of plants. Origin, diversity, structure and internal processes of plants.
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What are the 2 early ties we have to plants?
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Medicine and food/agriculture
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Who is the "Father of medicine" and what did he contribute to botony?
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Hippocrates; he used plants for medicinal purposes and wrote about them in Corpus Hippocraticum
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Who is the "father of botany"?
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Theophrastes
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What are Theophrastes accomplishments?
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1. Described plants in the context of what was known about animals.
2. Described over 500 species of plants 3. unsuccessfully attempted classifying as trees, shrubs, undershrubs, & herbs. 4. understood features important for modern plant classification |
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What is genus for air potato?
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Dioscorides
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What did Dioscorides contribute?
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He wrote De materia medica, precurser to all pharmacopeias. Historical use of medicinal plants for Greeks, Romans, etc.
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What has shaped human culture?
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Production, trade, and aquisition of crops.
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Change from nomadic life to full or partial agricultural subsistence was caused by what?
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Development of cereal grains.
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Cereal grains and where they originated:
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Corn: americas
Wheat, rye, barley: middle east rice: asia |
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Major plants of the new world:
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Potatoes, tomatoes, chiles, beans.
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What has fueled a worldwide change in plant distribution?
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Trade has caused invasive species and pests/blights.
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Disciplines of Modern Botany:
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Cellular level (plant molecular bio, biochem, cell bio)
Plant level (anatomy, morphology, physiology, genetics) Ecosystem level (ecology, systematics, paleobotany, forensic) |
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Characteristics of plants:
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Highly organized, tissues, organs, they interact within species & within communities (plants & animals).
Photosynthesis and produce cellulose. |
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What ouside stimuli do plants respond to?
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Light response
Temperature response moisture response touch response |
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Who developed the modern microscope?
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Anton van Leeuwenhoek
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Who discovered cells?
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Robert Hooke
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Who first identified the nucleus?
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Robert Brown
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Three methods to study cells?
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Scanning electron microscope (SEM) - scans outside film of metal w/ electrons
Transmission electron microscope (TEM) - transmits electrons through sample Light microscope - uses light |
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Prokaryotic Cells
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smaller
lack nucleus lack membrane bound organelles Bacteria/Archaea |
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Eukaryotic cells
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True nucleus
membrane bound organelles membrane bound nucleus protists, fungi, all higher plants/animals |
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Plant cells contain:
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rigid cell wall
cell membrane central vacuaole plasmodesmata chloroplasts (not every plant has) plastids (store things) |
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Plants DO NOT have:
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centrioles
lysosomes intermediate filaments cilia/flagella (except in some gametes only) |
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Nucleus structure and function
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Function:
Is directive Contains the complete set of genetic "plans" for everything DNA Structure: Separated from cell by double membrane (nuclear envelope), contains pores Inside is DNA Nucleoli (make/assemble ribosomes) |
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Chloroplast structure
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-Outer membrane
-Inner membrane -thylakoid disks (thin disks) -stack of disks is a granum -space between granum & inner membrane contains stroma (contain enzymes for Calvin Cycle) |
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Mitochondria structure
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-Outer membrane
-Inner membrane (cristae - highly folded) -Matrix (inside inner membrane) |
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Ribosome Structure
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-2 subunits
-composed of RNA and protein -free or bound to ER |
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Golgi Apparatus
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-Collecting & packaging center
-Proteins & polysaccharides -vesicles bulge off sides containing material |
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Vacuoles
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-membrane-bound sac filled w/ liquid (contains dissolved salts, ions, pigments, wastes)
-May occupy 90% of cell volume -maintain cell shape (turgor pressure, strengthens cells) -Temporary storage (above) |
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Turgor pressure changes with solution changes in what ways?
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-Hypertonic solution: cell will lose water & become Plasmolyzed
-Hypotonic solution: cell will gain water and become Turgid -Isotonic solution: cell will lose as much as it gains and become Flaccid |
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Cytoskeleton
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Protein fibers allow cell movement, help with structure, is within the cytoplasm.
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Cell Wall
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-Composed largely of cellulose (long-stranded polysaccharides, linked glucose molecules)
-Cellulose fibers bundled, multidirectional -Bundles are held together by pectin -Middle lamella (layer of pectin compounds, cements primary cell walls of adjacent cells together) |
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Cell wall function
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coating secreted by cells
supports/protects provides routes for water/minerals microtubules from cytoplasm through Golgi apparatus Thin primary cell wall produced first, stretches/expands. After cell stops growing, wall thickens/solidifies |
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What cements and what strengthens cell walls?
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Pectin cements cell walls together, lignin strengthens cell wall (together makes stronger)
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What are plasmodesmata?
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Tiny channels through adjacent cell walls. Connects the cytoplasm of the adjacent cells to allow small molecules and ions to pass through.
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Cell membrane structure
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double membrane of lipids
hydrophilic heads on outside, hydrophilic tails on inside away from water proteins embedded in membrane |
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Cell membrane function
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Passage of materials through selectively permeable membrane
Receive info from surroundings |
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Types of passage across cell membranes:
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Diffusion
Osmosis Facilitated diffusion Active transport |
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What is diffusion?
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Net movement of particles from area of high concentration to area of lower concentration by random motion
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What is osmosis?
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Net movement of water by diffusion through a selectively permeable membrane.
Special kind of diffusion. |
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Define hypertonic, hypotonic, and isotonic:
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Hypertonic: solution has higher concentration of solute than cell
Hypotonic: solution has lower concentration of solute than cell Isotonic: solution has equal concentration of solute to cell |
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Define facilitated diffusion:
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Movement of substances from higher concentration to lower concentration through special passageways in the cell (carrier proteins)
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Define active transport:
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Assisted movement of substances from area of lower concentration to area of higher concentration, against concentration gradient.
Requires energy (ATP), carrier proteins in cell membrane, K+ into cell, Na+/H+ out of cell. |
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What are the chemical processes in most plant cells?
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Photosynthesis and cellular respiration
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What are anabolic reactions?
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Chemical reactions that store energy inside the cell. Ex. photosynthesis
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What are catabolic reactions?
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Energy is released from molecules. Ex. Cellular respiration
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What is oxidation and reduction?
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OIL RIG
Oxidation is loss of electrons. Reduction is gain of electrons. |
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What is photosynthesis? What is the reaction?
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The storage of solar energy to chemical energy (stored energy)
CO2 + H2O --> C6H12O6 + O2 +H2O |
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What are the two cycles of photosynthesis?
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Light cycle (needing light energy) and the dark cycle (calvin cycle)
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What do the light reactions consist of? Where does it take place?
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Occurs in the thylakoid.
Light energy to chemical energy. Chlorophyl absorbs light/ e- gets excited to higher energy state. Transferred to acceptor molecule/lost e- is replaced by water splitting, oxygen is released. Temporarily stores energy from the split H+ in the form of ATP and NADPH. |
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What do the dark reactions consist of? Where do they take place?
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Occurs in the stroma (area between thylakoid membrane and inner membrane). Most common is Calvin Cycle.
Uses the energy from light reactions (ATP & NADPH) to convert CO2 into sugars (carbon fixation) for future use as polysaccharides which are easily stored in large #'s. Controlled by enzymes, depends on products of light reactions. RuBP + CO2 --> six carbon molecule |
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Why is visible light used in photosynthesis?
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Because there is not enough energy in the large wavelengths such as Infrared and too much energy in the shorter wavelengths such as UV, gamma, x-ray.
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What is a photon?
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They make up light, they are packets of light energy.
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The primary chlorophyl used in green plants:
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chlorophyl a, initiates photosynthesis in green plants.
Chlorophyl all have similar structure with Mg2+ center and different small side chains. Ring w/ Mg center is the part that absorbs light. |
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What are carotenoids?
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THEY ARE NOT CHLOROPHYL!!
Accessory pigments (red/orange), they help chlorophyl by expanding the spectrum for light absorption and protect chlorophyl and the thylakoid membrane from excessive light. When excited they transfer energy to chlorophyl a. |
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What are antenna complexes?
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Chlorophyl a, accessory pigments, and pigment binding proteins are arranged in units called antenna complexes.
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What are reaction centers?
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Antenna complexes absorb light and transfer it wo reaction centers, which consist of chlorophyl and proteins that directly participate in photosynthesis.
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Photosystem II
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Electrons are excited by light energy at different wavelength than PSI. Non-cyclic electron transport.
Water is split and O2 is produced. |
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Photosystem I
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Involved in non-cyclic electron transport (makes NADPH) as well as cyclic electron transport (makes ATP).
Cyclic Electron Transport: Does not split water, does not form O2, does not form NADPH |
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3 stages of the Calvin Cycle (C3 pathway):
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1. CO2 uptake
2. Carbon reduction 3. RuBP regeneration |
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Stage 1 of 3 stages of Calvin Cycle (C3 pathway):
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-RUBISCO fixes CO2 to RuBP forming 6 carbon molecule
-molecule splits forming two 3 carbon molecules (PGA) -Stage known as CO2 uptake -Cycle known as C3 pathway due to the 3 carbon molecules |
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Stage 2 of 3 stages of Calvin Cycle (C3 pathway):
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-Carbon Reduction
-2 molecules of PGA are converted to G3P using NADPH & ATP from light reactions -Every 6 turns of Calvin cycle produce 2 molecules G3P that are used in carbohydrate synthesis -They are paired to produce glucose or fructose |
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Stage 3 of 3 stage Calvin Cycle (C3 pathway):
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-Regeneration of RuBP
-10 G3P molecules remain & are converted to six 5 carbon RP (ribulose phosphate) -ATP's add a phosphate to each resulting in 6 RuBP |
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What is photorespiration & when does it occur?
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-reduces efficiency of C3 pathway
-occurs when plants are water stressed (lose more water than can bring in thru roots) -to conserve water plants close stomata -decreased CO2 uptake (remaining is used up) -O2 builds up (cannot be released) -RUBisCO binds to O2, degrading RuBP to release CO2 -DOES NOT produce biologically useful energy -Reduces growth |
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What plants have evolved to avoid photorespiration?
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Graminoids/grasses
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What is the most significant method for avoiding photorespiration?
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C4 pathway
NOTE: NOT deserts, it is tropical, where plants cannot take up enough water to replaced that lost |
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What makes C4 Pathway different from C3 pathway?
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The first molecule formed during carbon fixation in C4 is a four carbon compound (oxaloacetate) not three carbon (PGA) as in C3 plants.
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What does C4 pathway accomplish?
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It is used to efficiently fix CO2 when CO2 concentrations are low. Adaptation in tropical plants (graminoids)
Fixed into 4 carbon oxaloacetate CO2 initally fixed in the mesophyl cells and then transported to the bundle sheath cells where the CO2 is removed and enters the C3 pathway. |
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What is the result of the C4 pathway?
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The concentration of CO2 is high in the bundle sheath cells, higher than would occur as a result of atmospheric diffusion.
Photorespiration rarely occurs. Rubisco always has high concentration of CO2 available for calvin cycle. |
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What is the structural differences between C3 and C4 plants?
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Both have mesophyl cells and bundle sheath cells.
Mesophyl cells in C4 plants line up along bundle sheath cells, C3 plants only have them beneath the upper epidermis. C4 bundle sheath cells contain plasmids, C3 do not. |
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What is another alternative pathway to C3 other than C4?
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CAM
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Explain CAM pathway:
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Stomata open at night (temporal separation), this means no gas exchange during day. Normal photosynthesis is impossible.
CO2 taken in at night is fixed same way as C4 pathway (to malic acid) which is stored in the vacuole. During day, stomata are closed, but malic acid is converted to CO2 for use in C3 pathway. |
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What plants use CAM and why?
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Occurs in desert plants/nearly continuously dry. #1 priority is not losing water.
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What types of plants use the calvin cycle?
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ALL plants, it is used to make sugar from CO2.
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Aerobic Respiration
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Glycolysis, Citric Acid Cycle, Electron Transport
Occurs in Mitochondria Plants have to respire! Requires O2, release CO2 |
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Where does anaerobic respiration occur?
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In prokaryotes and eukaryotes that are in anoxic conditions.
Obtaining energy from glucose w/out O2 as final electron acceptor. Acceptor is an inorganic compound. |
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What is fermentation?
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Different anaerobic pathway. Inefficient and doesn't make as much ATP as aerobic.
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Where does lactate fermentation occur?
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Some prokaryotes, certain fungi, muscle cells; it produces lactate.
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What domain are Protista?
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EUKARYOTE!!!!!
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What characteristics do Protista?
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Unicellular or multicellular
Very diverse group. Autotrophic (absorb food/fungi-like) or heterotrophic (ingest food/animal like) or plant-like They have a nucleus and membrane bound organelles. Most aquatic/ terrestrial are in damp areas. Almost all have asexual stage, most have sexual |
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What is the sexual stage in protists?
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Syngamy (union of gametes)
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What types of asexual stages to protists exhibit?
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Fragmentation, fission, spores
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What types of motility do protists exhibit?
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Pseudopods, cilia, flagella, or combinations of these.
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Where did the ability to become photosynthetic come from?
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Long time ago a heterotrophic eukaryote engulfed a cyanobacteria that gave them the photosynthetic ability. Red and green algae split long ago in evolution.
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Characteristics of Euglena:
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Unicellular
Freshwater Pellicle (woven protein strands/coat) --> lack cell wall 2 flagella, 1 extrudes Long flagellum (locomotion) Eyespot (phototaxis)/orient toward light Chloroplasts (photosynthesis) nucleus asexual can form cysts when environment is harsh (dries up) |
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How do Euglena move?
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By use of 1 of their flagella, long whip-like structure located on anterior end, lasso water, pulls through water
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How are Euglena classified?
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Both Animal-like and Plant-like
Animal-like: they move, they can become heterotrophic if in the dark - absorb through their pellicle or use phagocytosis to feed/some are always heterotrophic Plant-like: Chlorophyl a & b, carotenoids, not close evolutionarily to plants |
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What allows Euglena to be phototaxic?
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Eyespot, primitive organelle, filters sunlight to structures at flagellum base. Adjusts position to enhance photosynthesis.
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Characteristics of Dinoflagelates:
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Most unicellular
Most biflagellated (one in transverse groove, one along longitudinal groove) - forward spiral motion Most have shells of interlocking cellulose plates (some contain silica 4 strength) Have fucoxanthin (carotenoid, yellow-brown pigment) Most are marine Respond quickly to increases in temp & nutrients |
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Dinoflagellate interactions with other species:
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Some are Endosymbionts: lack cellulose plates & flagella; photosynthesize & produce carbohydrates
Some are Parasitic: do not photosynthesize |
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What protist causes red tide?
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Dinoflagellates
Red tide is caused by a rapid proliferation of them. Exotoxins: produced from outer shell Endotoxins: produced inside (paralytic shellfish poisoning) |
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Why are dinoflagellates important?
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Primary producers of food in aquatic food webs.
Integral part of 1st link in aquatic food chain: photosynthesis (light to chemical energy) Major cause of Red Tide |
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Characteristics of Diatoms:
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Freshwater & marine (cool marine mostly)
Huge #'s Photosynthetic contain fucoxanthin (yellow-brown pigment) Silica shell/shoebox 2 main shapes: radially symetrical (wheel) & bilaterally symetrical (cigar shaped) Have cilia for movement (come thru holes in shell) |
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How do Diatoms reproduce?
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Mostly Asexual: division along 2 halves, smaller half becomes larger part of new box
Sexual stage triggered: zygote allows new diatom to become original size |
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What is Diatomaceous Earth & what is it used for?
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Sediment of dead diatoms.
Used for filtering materials, abrasive materials, insulating/sound proofing materials. |
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Characteristics of Foraminifera:
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Single celled w/ shells (tests), protoplasm covers shells, shells divided into chambers added during growth.
CaCO3 shells/tests. 1 or many nuclei Largest species have symbiotic relationship w/ algae which they farm Almost all marine in sediment. Have pseudopodia/rhizopods/reticulopodia |
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What types of reproduction do Foraminifera exhibit?
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Sexual: gametes released into water/sperm fertilize
Asexual |
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Characteristics of Radiolarians:
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Needle-like pseudopodia/rhizopods for buoyancy/capturing prey
Often contain symbiotic algae Exoskeletons are silica |
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Phyla of Algae:
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Chrysophyta - golden
Phaeophyta - brown Rhodophyta - red Chlorophyta - green |
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Characteristics of Chrysophyta:
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"golden algae"
Unicellular flagellated or flagellated colonies Have chloroplasts Carotenoids (fucoxanthin - yellow-brown) Mostly freshwater 2 flagella Release unique toxins that affect gill breathing Toxicity increases with pH |
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Characteristics of Phaeophyta:
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Brown Algae
Blade, stipe, holdfasts (parts of algae) Almost always marine (cooler) Air bladders for buoyancy Fucoxanthin cooler marine forests (kelp) Multicellular/Giants (kelp) Photosynthetic Variety of ways to reproduce |
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Importance of Phaeophyta to humans:
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Food source
Algin (thickening agent) Antiseptic (iodine) |
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Characteristics of Rhodophyta:
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Multicellular
Highly varied organization of plant body "red algae" Phycoerythrin (red accessory pigment) More similar to cyanobacteria (Chlorophyl a & carotenoids/ pigment composition) Cell walls: sticky agar & carageenan (polysaccharides) Warm marine waters Photosynthetic Some put CaCO3 in cell walls reproduction not thoroughly studied |
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Chlorophyta Characteristics:
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Mostly fresh water
Unicellular (motile or nonmotile, colony or not) |
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What characteristics tie Chlorophyta to the evolution of higher green plants?
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Have chlorophyl a & b, & carotenoids
Starch is main energy reserve Cell walls made of cellulose |
