Flashcards in Midterm - Definitions Deck (149):
1
Phycology / Algology
study of algae, derived from Greek phycos for seaweed (Latin fucus=seaweed)
2
Species vs Taxa
Species: ability or inability to reproduce, but term doesn’t work for algae since clones of algae can reproduce causing no genetic recombination
Taxa: a group of distinct organisms, different things, used instead of species
3
Heterogeneous
a very diverse group
4
Monophyletic
descended from a common evolutionary ancestor and are all related, algae are NOT monophyletic, phenetic classification instead
5
Phenetic classifcation
use of physical appearances or morphological characteristics to classify into different groups
6
Binomial systems
genus+specific epithet, a naming system used for algae
7
Cryptogamic
-the sexual organs (no true flowers or seeds) are not seen or don’t have them, algae and bryophytes fall into this category
-hidden wife
8
Numerical aperture
ability to see two discrete objects with a good microscope, with a poor one you will only see one object
9
Transmission Electron Microscopy (TEM)
uses the passing of electrons to pass through an object, varying degrees of transmission will create an image to see the interior (subcellular organization) of things like cells (cross-sections)
10
Scanning Electron Microscopy (SEM)
take an object and coat it with a thin layer of gold and bombard it with electrons, depending on height or depth, you will get a 3D appearance of the exterior of an object
11
Electrophoresis
-Used to separate nucleic acids (DNA and RNA) through viscous gel where electric field causes negatively charged nucleic acids to migrate to positive anode
-used in Population genetics to look at variations and similarities between organisms
12
Chromatography
-Separation of mixtures of pigment based on relative rates of travel (uses mobility) in a medium based on differential partitioning between mobile and stationary phases ( polarity of molecules)
-Useful for examining biochemistry (composition of pigments, fatty acids, amino acids, nucleic acids)
13
Radioisotope
-14C is unstable (12 C is common form, 13C is stable)
-give algae 14C then the organism becomes radioactive and if an organism eats the algae it will also become radioactive
14
Thallus
-algae (if multicellular) have undifferentiated vegetative tissue (no specialization, body cells that are all the same) = thallus
-Rarely is there evidence of coordinated activity
15
“Phyta” vs “Phycos”
Phyta-plant
Phycos-algae
16
Autotroph vs heterotroph
Autotroph: feed themselves, raw materials, sunlight
Heterotroph: can’t feed themselves so rely on other organisms for organic material
17
Photolithotrophy
sunlight, inorganic raw materials like rock or material
18
Obligative vs Facultative
Facultative: you can switch from autotrophs to heterotroph depending on environment
Obligative: no choice on which method of acquiring nutrition
19
Colonial
-Clusters or aggregation
-number of flagellates linked
20
Coenobium
four cells together, usually multiples 2,4,16 by reproduction, number of cells is fixed, specific type of colony
21
Trichome vs filament
Trichome: linear chain of cells, hair or scale-like
Filament: a linear chain of cells surrounded by a mucilage coat that can be branched or unbranched
*trichome+mucilage sheath=filament
22
Pseudoparenchymatous:
-chain of cells but can’t distinguish them individually
-a tissue that resembles the parenchyma (connective and supporting tissue) of plants, but isn’t its pseudo=false
23
Binary fission
cleaving of the two cells, simple reproduction
24
Haplodiplontic
haploid (haplontic) stages and diploid (diplomatic) stages of reproduction
25
Thylakoids
flattened membrane bound sack where pigments occur for photosynthesis
26
Phycoplast vs Phragmoplast
Phycoplast: simpler algae’s microtubule structure during cell division
Phragmoplast: in vascular plants, more advanced, involves microtubules during cell division
27
Cyanelle
-a photosynthetic organelle of Glaucophyta or Glaucophytes (endosymbiotic Cyanobacteria) that is not pigmented
-NOT a chloroplast
-Like cyanobacteria, cyanelles have unstacked thylakoids and contain chlorophyll A, phycobilins, own DNA (5-10% of free-living cyanobacteria, probably due to gene transfer), but they cannot live independently and have no respiratory electron transport
-was once a free-living organism
28
Chloroplast
-Basic structure is 2-4 layered membrane-bound vesicle enclosing thylakoids in matrix (stroma)
-Number of membranes is a clue of their evolution, so more membranes=more advanced organism (not primitive)
-involved in photosynthesis
29
Grana
stacks of thylakoids to make this complex mechanism for photosynthesis
30
Achlorophyllous
Some algae don’t have chloroplasts or chlorophyll
31
Shapes:
A) discoid
B) stellate
C) reticulate
A) disc shaped like a coin
B) star shaped
C) net shaped
32
Vacuole
Storage space
33
Gas vacuole and the Cyanobacterial cell
-Self-erecting cylindrical vesicles containing atmospheric gases
-exception of an organelle, some prokaryotes have them
-All Cyanophyceae except Chamaesiphonales have gas vacuoles
-makes them buoyant depending on amount of gas (Cyanobacteria are positively buoyant, humans are negatively buoyant which means that density is higher than water) so they collect at the surface of the water
*only algal group that is buoyant
-Accumulation of photosynthate (glucose made during photosynthesis) increases cell turgor pressure, causing collapse of gas vacuoles
***KNOW THIS
Cyanobacterial cell has lots of light, can do lots of photosynthesis, which increases glucose, increases turgor pressure, which bursts the gas vacuoles and it begins to sink. When it gets deeper, It can do less photosynthesis, decreases glucose production, decreases turgor pressure, increases gas vacuoles and floats back up to the surface
34
Pigments
-Molecules that absorb light
-biochemical
-complex
-big
-not created by chance
35
Chlorophyll
-used to produce ATP and NADPH during photosynthesis
-Can only absorb blue and red light, so appear green
-all algal groups have two at most, always Chlorophyll a, then either b,c,d
36
Photosystem I vs II
Photosystem I is most primitive and evolved first, does not produce oxygen (anoxygenic)
Photosystem II evolved after, produces oxygen (oxygenic) by splitting water (how algae produced our oxygenic atmosphere)
*Only organisms with both photosystem I and II can produce oxygen, except in specialized cells like heterocysts that have PSI only
37
Heterocysts and how they differ from vegetative cells
-specialized cell in Cyanobacterium (blue green algae) or filamentous Cyanophyta
-NOT a prerequisite for nitrogen fixation (Microcystis has no heterocysts but can fix nitrogen)
• Differ in appearance from vegetative cells:
-Larger and thicker cell wall
-Refractive polar nodules at connections with vegetative cells
-Cell contents homogenous and yellow in colour
-May be intercalary in filament where they are spaced at regular intervals or terminal
-Thought to function in nitrogen fixation, N2 to NH3 or ammonia
-The further away from the heterocyst, the lower the nitrogen concentration; distance between heterocysts indicates the concentration of nitrogen in the environment; ammonia diffuses to neighbouring cells, change in concentration in neighbouring cells of the heterocysts gives proof of hypothesis
-produced in low nitrogen environment
-number of heterocysts is a clue to how nitrogen limited they are (Number of heterocysts typically correlated inversely with N concentration of environment)
-Only has photosystem I (doesn’t produce oxygen=anoxygenic), an anaerobic process
38
Anoxygenic vs Anaerobic
Anoxygenic: carrying out photosynthesis where no oxygen is produce as a byproduct
Anaerobic: requires the absence of oxygen (can’t live in oxygen)
39
Accessory pigments
-Maximize energy intake, principally in PSII during photosynthesis
-Chlorophyll, Carotenoids, Phycobilin
40
Carotenoids
-brown, yellow, orange, red
-increase useful range of absorbed light, and protect photo centres from excessive light
-ex) Beta-Carotene, Fucoxanthin, Peridinin, Siphonoxanthin
41
Phycobilins
-red or blue-green
-pigments found exclusively in Cyanophyta, Cryptophyta, and Rhodophyta
-Phycoerythrin (red)
-Phycocyanin (blue-green)
42
Glucose
-Produced by dark fixation of CO2 and energy products of light reactions
-May be used immediately to meet energy requirements of the cell
-Product of photosynthesis
-Organism may store into glucose polymers (High molecular weight compounds or Low molecular weight compounds)
43
Coccoid
Spherical or elliptical, non-motile (*difference with unicellular) cells surrounded by walls, sometimes in colonies
44
Rhizopoidal/amoeboid
-not a standard form
-like an amoeboid that changes shape
-Naked cells with pseudopodia (no cell walls)
45
Palmelloid
-cells are all in one plane (flat plate) in a colony or coenobial
-Non-flagellated cells, usually naked, embedded in common envelope of mucilage on a flat plate
46
Uniseriate vs Multiseriate filaments/trichomes
Uniseriate: one cell wide filament
Multiseriate: more than one cell wide filament, more complex
47
True branching vs false branching
True branching: during division the two cells still remained attached and created a radiating pattern of branching, in a second plane
False branching: mucilage coat, where a second filament which is not actually connected but remain together due to the coating, Cyanobacteria do this (filamentous with a coat); outgrowth adjacent to dead or specialized cells
48
Groove/sulcus/singulum
A concave ring around the cell where a flagellate is tucked in
49
Isthmus
-distinctive narrowing in the centre of the cell in desmids
- during asexual division, the cell divides across the isthmus, but starts to expand outwards to form another semi-cell
50
Pellicle
-Exclusive to Euglenophyta (euglenids)
-a cell coating, cell membrane’s specialized structure
-corrugated membrane with strips of protein in each depression followed by microtubules; in the grooves are muciferous bodies; at bottom of grooves is mucilage that acts as a lubricant to help the cell twist and untwist to help with friction and create propulsion= Euglenoid motion
51
Stigma/Eye spot
-involved in motility by sensing light to direct the euglena towards or away from light=phototactic responses
-Many flagellated cells have swelling close to base of one flagellum, usually aligned with flagella
-Referred to as paraflagellar body (rod shaped) or photoreceptor
-Packet of coloured pigments other than green (red, orange) that stands out
-Two part “eye” is not like ours: one a packet of pigments and the other is a photoreceptor (Pigments used to shade the photoreceptor)
52
Scales
-inorganic silica pieces or plates which covers the cell, as well as organic material like carbohydrates
-Mostly in Chrysophyta
-Scales formed in vesicles at Golgi apparatus, migrate to plasma membrane and are “budded” to exterior where they aggregate in patterns (Are on the outside of the plasma membrane but is produced inside the cell)
-May be plain or ornately patterned, species-specific (useful as diagnostic in paleolimnology)
-Function in protection and, by increasing surface area, aid in buoyancy
-Composition variable: inorganic (calciate, silica) or organic (carbohydrates) or both
-If silica scales fused together, it could resemble a lot like the frustule
53
Spines and horns
-defence, dissuade herbivores from eating them
-increase surface area
-increases drag to slow down its sinking
-helps to float
-helps link cells into long chains
-problem for fish where the diatoms get stuck in the gills and causes asphyxiation
54
Lorica
-looks like a wine glass or trumpet shaped cell with an opening at the end or conical sheath
-cell wall that does not go all the way around the cell=incomplete cellulose-based cell wall that forms a sheath that contains a naked cell
-each lorica has one naked cell
-Flagella come out of the open end of the lorica to provide for locomotion and provision of food
55
Cysts
-form of reproductive structure to help survive adverse environmental conditions
-cysts are red, the organism is green in its vegetative state
-formed from zygote (sexual) or vegetative (asexual) cell
-Another means of restoring population size in marine centric diatoms after becoming too small from cell division (asexual reproduction)
-Looks like a zygote or auxospore
-ASEXUAL process
○ Means of surviving adversity or return original size
56
Akinete
-asexual reproductive structure
-modified vegetative cell or resting spores unique to Cyanophyta when exposed to stressful conditions
-can generate a new filament if broken off
-stores the products of photosynthesis, abundant polysaccharide reserves for long periods of dormancy
-more granular in appearance, less pigmentation
57
Whorls of branches
branches coming off one point and radiating into all directions
58
Nucule vs Globule
-reproductive structures are wrapped around by sterile cells
-Nucule=female
-Globule=male, are motile
59
Periplast
-modified plasma membrane
-Exclusive to Cryptophyta (cryptomonads)-“crypt”=hidden or unknown
-outside plasma membrane are granular fibrils while inside are hexagonal or rectangular plates of protein interrupted by ejectosomes
60
Ejectosomes
-vesicles like a party blower that unrolls when you blow in it
-can be used for motility or to scare away predators
-Exclusive to Cryptophyta
-Discharged from cell body when irritated, propelling cell in opposite direction
61
Thecal plates
-Exclusive to Dinophyta (dinoflagellates)
-Vesicles below membrane contain unknown fibrillar compound (non-cellulosic) below which are microtubules
-Like paroplast
-Vary in size from nonexistent to thin to thick
-Exist under cell membrane (not armour)
62
Frustule
-Exclusive to Bacillariophyceae (diatoms, from Greek “diatomos”=cut in two)
-Made primarily of polymerized silica (95% + composition)with some organic (sugars, lipids, amino acids)
-Exterior to plasma membrane
-Composed of two interlocking valves (epitheca, hypotheca) connected by one or more cingular bands (girdle)
-Epitheca is the bigger of the two and covers the hypotheca
-Frustular morphology is basis for diatom classification
-Like a Petri dish on the outside of the cell membrane (exterior)
-Resistant to decay so accumulate in the sediments as fossils, a record of past ecological conditions, creates a timeline
63
Amorphous
An irregular morphology
64
Cell wall
-Generally comprises two parts: fibrillar part (skeleton) and amorphous part (matrix in which fibres embedded)
-Most abundant ingredient: cellulose but may be replaced by mannan or xylan in some Chlorophyta
-May be calcified, Charophyta has calcium carbonate on the exterior
-Usually complete but may be incomplete, such as lorica in some Chrysophyta and Euglenophyta
65
Mucilage
-a mixture of sugars, proteins and water that creates a clear slime
-Protection from desiccation (create a buffer against drying out), protection from grazing, buoyancy (slows down sinking)
-Allow for distance away from the plant, rock or animal by having a stalk (very long compared to the frustule, like a lollipop), gives advantage to get to water with more nutrients, more light
-Cyanophyta cell wall can be embedded in mucilage sheath, Diatoms in mucilage tubes or sheets
-Creates a filament, glues things together
-Diatoms use to escape from salt water, make slime trails ; Centric (do not produce slime) and Pennate (produce slime)
-Mucilage may be secreted from frustular pores
-used in our cosmetics to add texture by alginate
-bind soil, reducing erosion
66
Aplanospore
A non-motile method of reproduction
67
Flagella
-Vegetative cells, some stages in algal lifecycle (zoospores), most common in unicellular eukaryotes freely suspended in water have them
- Vary in number from 1 to >100 per cell
-Cross section of 9+2 microtubules anatomy
-Used for motility or food gathering instrument (Carnivorous Dinoflagellate uses it as a grappling hook)
-End with the eye spot is where mostly the flagella are located
68
Isokontous vs Heterokontous vs Haptonema Flagella
Isokontous: Flagella similar in length and type
Heterokontous: Dissimilar flagella, of unequal length, and/or one smooth and one hairy (“tinsellated”), different degrees of motility
Haptonema: Superficially resembles flagellum but different internal anatomy; function uncertain but may be used for defence, food capture, or attachment; exclusive to Division Haptophyta; curled
69
Name of various smooth and hairy flagella
Hairy (little threads on the Christmas tree): tinsellated=pantonematic=mastigonemes
Smooth: acronematic
70
Hemodynamic vs Heterodynamic
Hemodynamic: move in same direction
Heterodynamic: flagella point in different direction
71
Gliding
-Non-flagellar movement
-Slow, gliding motion
-No visible organ responsible
-May be due to regularly arranged fibrillar extensions of the protoplasm
-Found in Cyanophyta
72
Euglenoid movement
-Non-flagellar movement
-Exclusive to Euglenophyta
-Due to contraction and expansion of pellicular bands
-Use of the pellicle to allow twist of the membrane with lubricant (lengthening and shortening)
-Cause unknown, may be associated with cytoplasmic streaming
73
Polyploid
multiple copies of each individual gene
74
Sporangium vs Gametangium
Sporangium: Spore producing cell, diploid
Gametangium: Carries the gamete, haploid
75
Encystment vs Excystment
Encystment: to create a cyst or go into a cyst state
Excystment: coming out of a cyst
76
Sexual reproduction
-No record in many algal groups
**Function of sex in algae does not occur for genetic diversity BUT for surviving adverse conditions or environment
*sex is not a precursor for success
-After each cell division, the cells get relatively smaller, but sexual reproduction is used to restore vegetative size
77
Isogamous vs Anisogamous vs Oogamous (sexual reproduction)
Isogamous: morphologically similar gametes, + and -, most primitive form
Anisogamous: Two gametes look the same but one of the cells migrates to the other, so has a distinguishing characteristic (male cell was motile and moved to the female cell)
Oogamous: us, two dissimilar gametes, one small motile male gamete (sperm) and one non-motile gamete (egg) = zygote, most advanced form
78
Haplontic vs Haplodiplontic vs Diplontic (algal lifecycles)
Haplontic: predominantly haploid stage
Haplodiplontic (diplohaplontic): alternation of generations between gametophyte (gamete-producing generation) and sporophyte (spore-producing generation) stages
Diplomatic: predominantly diploid stage ***only the zygote
79
Auxospore
A means to escape adversity of the environment
80
Prokaryote vs Mesokaryote vs Eukaryote
-Prokaryotes: coiled DNA, no nucleus or other organelles
-Mesokaryotes: chromosomes but no interphase and no histones, organelles, intermediate nucleus (intermediate in evolution of prokaryotes and eukaryotes)
Eukaryotes: chromosomes, nucleus and other membrane-bound organelles
81
Algal Distribution: Aerial and Terrestrial Environments
a) Symbioses
b) Animals
c) Epilithon
d) Edaphic
e) Sympagic
f) Cryophyton
g) Epixylon
h) Epiphyton or epiphytic
a) Symbioses (lichens)
b) Animals (endozoic=living inside animals)
c) Epilithon (rock surfaces)
d) Edaphic (soil)
e) Sympagic (with ice)
f) Cryophyton (cold surface)
g) Epixylon (wood surface)
h) Epiphyton or epiphytic (algae living on plants)
82
Algal Distribution: Aquatic
a) Phytoplankton
b) Neuston
c) Metaphyton
d) Periphyton
a) Phytoplankton (free floating)
b) Neuston (air-water interface, Euglena sanguinea)
c) Metaphyton=elephant snot (formerly attached)
d) Periphyton (attached, any algae associated with a surface like plastic, a car, an artificial or human surface)
83
Microevolution vs Macroevolution
Microevolution: small microscopic changes
Macroevolution: large changes
84
Phycobilin series vs Fucoxanthin series vs Non-Masked series (pigments)
Phycobilin series:
-Cyanophyta, Rhodophyta, Cryptophyta
-No motile stages in lifecycles
-phycocyanin (blue-green) and phycoerythrin (red)
Fucoxanthin series:
-Phaeophyta, Chrysophyta, Bacillariophyta
-All contain yellow-brown-orange fucoxanthin pigment
-All produce laminarin and chrysolaminarin
-All produce motile stages somewhere in lifecycle
Non-masked series
-Chlorophyta, Euglenophyta, Xanthophyta
-Photosynthetic pigments not masked by accessory pigments
-Green produced by chloroplasts
85
*Ralph Lewin
-found an organism unidentifiable that didn’t fit into classification systems and spurred the revolution=Prochloron or Prochlorophyta (before Chlorophyta, green algae)
-translated Winnie the Pooh into Esperanto (create an international language, simplified language easier to learn, to make it easier to communicate with everyone around the world)
-first to write a book in the field of coprology (scientific study of fossilized feces), recycling of organic material
86
Prochloron (Prochlorophyta)
-discovered 1975 by Ralph Lewin
-thought by many to be an intermediate form between prokaryotes and eukaryotes
-No phycobilins (All Cyanobacteria have phycobilins)
-Chlorophyll B in addition to chlorophyll A
-Thylakoids stacked in pairs, not monolayers
87
Autogenous Theory vs Xenogenous Theory
Autogenous theory:
-“self-creating”
-Eukaryotes evolved through step-by-step changes in photosynthetic, respiratory and genetic units (slow and gradual)
-Gradual compartmentalizations and specialization of function
-Nucleus can form itself and destroy itself during mitosis (membrane)
-Flagella are consistent within all organisms that have them
Xenogenous theory:
-Prokaryotes obtained organelles via series of endosymbioses (cells eat other cells) with other prokaryotes
-Mitochondrion and chloroplast have their own extranuclear DNA, and divide autonomously from nucleus via binary fission (like Bactria)
-Glaucophyta contain endosymbiotic cyanobacteria (cyanelles) that perform chloroplast function
- Some dinoflagellates also contain endosymbiotic cyanobacteria (phaeosomes)
88
Lynn Margulis
-wrote paper “The origin of mitosing eukaryotic cells” built on work of 19th and 20th century scientists
-First to rely on direct microbiological observations
-stuck to endosymbiosis theory
-Science discoveries not taken seriously, maybe due to being a woman
89
Endocytosis vs Phagocytosis
Endocytosis: bring material into the cell
Phagocytosis: bring in large materials into the cell, through endocytosis, a solid particle is brought into the cell by an infolding of the cell membrane as a vesicle and digested by the cell
90
Primary Endosymbiosis vs Secondary Endosymbiosis
Primary endocytosis:
-Gram-negative Cyanobacterium (Glaucophytes) are taken up by a bigger cell and are not digested so live inside it(identified by crystal violet if does not turn purple); have two unique outer membranes, and in between is peptidogylcan (polymer of muric acid or murein)
-Phagosomal membrane was lost, so the chloroplast only has two membranes (should have had three)
Secondary Endosymbiosis:
-4 membranes in eukaryotic chloroplast
-Nucleomorph buried in central core is residual genetic material
*chloroplast membranes: 2=primary, 4=secondary
* But chloroplasts of Euglenophyta and Dinophyta have more than two membranes, perhaps because an entire eukaryote (with its two membrane chloroplasts) was ingested (tertiary endosymbiosis?)
91
Nitrogenase
Enzymes produced by Cyanobacteria/Cyanophyta to fix nitrogen (N2 to NH3)
92
Axenic Culture
-does not contain foreign organisms, a pure culture
-Need to treat it with antibiotics to make it an agency culture, but it is very hard to get an axenic culture of Cyanobacteria due to antibiotics that destroys their capability of building cell walls with muramic acid
93
Simple dichotomous key
system of identification, two alternatives offered, follow the key to find out which organism it is based on yes or no questions, look at two alternatives and find which one corresponds to the organism
94
Alginate
-a chemical that comes from algae that is found in many of our products, food, cosmetics, anything that has texture
-made of mucilage
95
Tapered trichome
gets progressively wider as you go down the organism
96
Hormogonia (hormogonium=singular)
-filament fragment detaches and forms new filament forms
-motile filaments of cells formed during asexual reproduction of Cyanophyta
97
Endospores vs Exospores
-both produced during asexual reproduction
Endospores: produced inside of another cell
Exospores: produced externally where the bud buds off (yeast)
98
Crusts
-help to retain moisture in soil
-leathery material, looks like a brain
-very well adapted to dry environments (outer layer protects from this, underneath is moist)
99
Thermophiles
-love high temperatures (hot springs)
-Prokaryotes are better adapted for higher temperatures than eukaryotes
-Photosynthetic’s upper range is 60 degrees
100
Symbiont
-two organisms in close association with each other
-lichen is a fungus and alga association, lichen is not a species due to being two separate entities, fungus provides most of the biomaterial
-Phycobiont: provides food to the fungus
-Blue green spheres inside the diatoms, very first eukaryote fixing nitrogen but once looked closely the diatom had phycobiont (symbiotic cyanobacteria living inside the diatom) and was not actually a eukaryote that does nitrogen fixation
101
Bernal Diaz del Castillo
He observed that people living in the vicinity of Mexico City “sell some small cakes made from a sort of ooze which they get out of the Great Lake, which curdles and from this make bread having a flavour something like cheese”
102
Lake Blooms/Cyanobacterial blooms
-Common genera include Microcystis, Anabaena, Aphanizomenon (Mike, Annie and Fannie)
-Produce toxins as a by-product
-Have a high temperature tolerance and adaptable to light
-Nitrogen fixation gives them advantage when N is low
-Occur when nutrient enrichment, especially N and P, favours excessive growth; N and P are increased in lakes due to sewage
-Oxygen depletion (summer=blooms or winter=thick ice)
-Aesthetic impairment (taste and odour)
-Act of decomposition consumes oxygen (huge plummet in oxygen levels in water that fish require to live)
103
E3 Live (Aphanizomenon flows-aquae)
-Food supplement
-Wild-harvested is worrisome due to not being grown in a controlled environment
104
Toxins vs Toxicants
Toxins: something that is of biological origin (snake venom)
Toxicant: something that is toxic not of biological order (pesticides), very inclusive or anything harmful to organisms, includes toxins, includes human made things
105
Neurotoxins vs Hepatotoxins
Neurotoxins: affects muscles, functioning of the brain, effects on memory, communication, walking, outcome usually death
Hepatotoxins: affects the liver
106
Beta-methylation-L-alanine (BMAA)
-Modified amino acid
-Research from Sweden, Scotland, and USA that BMAA may be connected to degenerative nerve diseases like ALS (Amytrophic Lateral Sclerosis “Lou Gehrig’s Disease”), Alzeimer’s, and Parkinson’s (memory loss) = Neurotoxins
-BMAA is produced by cyanobacterial endosymbionts of cycad roots in Guam
-biomagnification=Flying foxes are eaten whole by Chamorro people of Southeast Asia, which may explain high incidence of neuro-degenerative diseases in this region
107
Biomagnification
As it goes up a food chain, the higher the concentration of the toxins gets in each stage.
108
Seven Pillars of the BMAA-ALS Hypothesis
1. Cyanobacteria produce BMAA
2. BMAA exposure is ubiquitous
3. BMAA can be inserted into proteins
4. BMAA can be biomagnified within ecosystem
5. BMAA is neurotoxic to motor neurone
6. Individuals vary in vulnerability to BMAA
7. BMAA occurs in brain tissue of ALS and Alzheimer’s disease patients but not health controls
109
Symmetry: Centric vs Gonioid vs Pennate vs Trellisoid
Centric: radial or isodiametric
Gonioid: trilateral, triangular symmetry in marine diatoms, three poles of symmetry
Pennate: bilateral, human body, symmetry on one axis or two
Trellisoid: perspective drawing, radiates (NOT radial) symmetry
110
Epivalve and Hypovalve
-two valves of the frustule in Diatoms
Epivalve: larger valve, also called epitheca
Hypovalve: smaller valve, also called hypotheca
111
Cingulum/Girdle
-groove or band where the flagellum is tucked in
-separates the epivalve and hypovalve of the frustule in Diatoms
112
Raphe
-Longitudinal fissure in valve surface of pennates
-Slit that runs from one end of the frustule to the other
-May help diatoms in gliding motility
113
Araphidinate vs Monoraphidinate vs Biraphidinate vs Pseudoraphidinate
Araphidinate: no raphe on either valve
Monoraphidinate: raphe on one valve
Biraphidinate: raphe on both valves
Pseudoraphidinate: clear area in centre of valve without fissure
114
Striae
-Frustule component
-Lines on surface of valve
-Little distinct rows of dots (at low magnification it looks like a line)
115
Punctae (Punctum=singular) / Areolae (areolum=singular)
-Frustule component
-Depressions in the silicon
-Sometimes go all the way through
-Important diagnostic
-All the little dots that make up the striae
116
Costae
-Frustule component
-More heavily silicified ribs between rows of striae
117
Processes (rimoportulae)
-Frustule component
-Solid protrusions on inner or outer valve face
-Processes=knobs
-Hold cells together in chains (looks like a zipper)
-Reduce sinking rate by increasing surface area
-Discourage grazing
-Mucilage extrusion
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Lamellae
Thylakoids grouped in three in chloroplasts
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Pyrenoids
areas of chloroplasts where photosynthesis is taking place (turn blue black when iodine applied due to concentration of starch in pyrenoids)
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Auxotrophy
-require one or more organic nutrient (vitamins)
-Vitamins provide amines not produced by the human body but needed to survive
-Vitamin B12 is needed for algae, but can’t produce it themselves = auxotrophic
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Mixotrophic
-grow depending on favourable conditions and switch accordingly back and forth
-lots of light=photosynthetic, no sun=heterotrophy
-a cost of compromise, can’t grow as quickly as those who are obligate
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Macdonald-Pfitzer Rule
-Research on diatom reproduction
-When daughter about 1/3 of original parental size, they become incapable of further size reduction and must undergo size regeneration
-More generations you get, the smaller they get (1/2 size every single time the smallest diatom divides)
-At around 1/3 of parental size, then this initiates sexual reproduction (used to restore original size to the population or to survive adverse environment)
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Resting cell and compare to vegetative cell
-Common in freshwater, pennate diatoms
-Similar in appearance to vegetative cell with fewer mitochondria and larger lipid bodies
-Sink to bottom of water body, remain viable > 2 months
-Cell not doing anything
-Frustule is unchanged
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Epipelon-Diurnal Migration
-epipelon/epipelic: associated with mud of puddles
-diurnal: changing over the course of the day
-where algae migrate to the surface of the mud and water to be exposed to sunlight
-Move back into the mud at night to escape from predators by burrowing down into the mud (triggered by sunlight)
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Haptobenthic
-Associated with a firm surface (wood, rock), can’t burrow into the surface
-Benthic: surface
-Diatoms are glued onto the surface of the sand, to prevent separation from it, bumped around by other grains of sand during tides
***Exam: Dynamic place or quiet? Dynamic since they are firmly glued to the surface of the sand. If stalk not found on sand, probably in a stable place
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Estuary
where salt water and fresh water flow in together
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Terra-forming
to create a habitable environment (create life form on another planet)
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Nutrient Requirements to grow diatoms
C. Hopkins Café. Mighty good but not always clean. Comin’ cousin Moe? Si!
CHOPKNS CaFe Mg B NaCl CuMn CoZn Mo Si *macronutrients listed first and micronutrients
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Paralytic Shellfish Poisoning (PSP)
• Toxin domoic acid produced by marine diatom Pseudonitzschia pungens
• Toxin accumulates in flesh of filter-feeding animals such as mussels, clams
• Domoic acid is excitatory amino acid causing nerve cells to continuously transmit impulses until they die
• No antidote and no way to remove toxin from tainted food
• Many fewer toxins in diatoms compared to cyanobacteria
• Paralysis=Neuro toxin
• Consuming contaminated shellfish cause this condition
○ Are filter feeders, the algae they eat is the problem
○ They themselves are not affected but we are
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Precipitation deficit vs Precipitation surplus
Precipitation deficit: less water coming down than coming back up into the atmosphere
Precipitation surplus: more water coming down than going back up into the atmosphere
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Oligotrophic vs Eutrophic Conditions
Oligotrophic: poor nutrient conditions, nutrient poor and chemically-dilute water
Eutrophic: nutrient rich conditions
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Autocolonies
During mitotic reproduction, one cell will divide into four and become cells of a brand new colony (self-replication)
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Xenic
presence of foreign organism in a culture
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Hormesis
what could be beneficial in one quantity, whereas not beneficial in another quantity (too much of a good thing is a bad thing)
Ex) Auxin (normally occurring plant hormone that can help growth) and 2,4-D (similar to auxin but kills plants)
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Monod Model of Growth
-Jacques Monod proposed a model for growth related to the concentration of the growth-limiting nutrient (GLN)
-Threshold (T): minimum amount of the resource that gives growth
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Unicellular vs Coccoid Morphology
Unicellular: Free-living with flagella, motile
Coccoid : Spherical or elliptical, non-motile (*difference with unicellular) cells surrounded by walls, sometimes in colonies
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Thalloid (morphology)
-Cells united in pseudoparenchymatous plate-like thallus
- 3D filaments where they are not distinguishable individually
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Tinsel vs Whiplash Flagellum
Tinsel flagellum: covered in tubular hairs (mastigonemes), used for motility and for capturing food
Whiplash flagellum: very fine hairs or none at all, usually shorter and sometimes serves no role in motility but more for helping tinsel flagellum to bring food closer to the cell for phagocytosis, has swelling at base which contains photoreceptor (electron dense area), eyespot (near chloroplast) and flagellar swelling interact in response to light direction (phototaxis)
○ Both flagella with typical 9+2 microtubular anatomy
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Peripheral chloroplast
A chloroplast that goes around the cell
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Muciferous bodies
-A projectile
-Contain granular mucilage bounded by single membrane
-When discharged, contents form fibrous network outside the cell
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Discobolocysts
-A projectile
-Similar to muciferous bodies
-Located in outer layer of cytoplasm; single membrane-bound vesicle with hollow, ring-shaped disc in outward-facing part
-Not a reproductive structure, only refers to its spherical shape
-Has a chamber with a little string and disc at the end and discharged out of the membrane (disc at the end of a string)
-Means of motility or anti-predator weapon
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Statospores (sometimes called Cysts)
-Can be formed sexually or asexually
-Siliciceous-walled (silica) sphere into which cytoplasm contents flow, plugged with unsilicified material (polysaccharide)
-Usually formed inside vegetative cells, inside the plasma membrane (***frustule formed outside the cell)
-Germinate when conditions improve, plug dissolves, protoplast emerges and forms flagella as it moves out
-A resistant stage, shuts down until environment is more favourable
○ Formation:
§ At early stage it is a thin membrane
§ As it progresses, it gets thicker and thicker
§ A hole gets filled and forms a protein plug
§ The contents outside the statospore is discarded
§ New membrane is formed inside the statospore
-Don’t break down in lake sediments and, due to ornate pattern on external surface, are diagnostic features for species that produced them
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Dioecious
-Oikia or Oikos = home
-Dioecious = “oecious” comes from “oikia”
-Two places in the reproductive structure, two strains (male and female or male and female) or two houses
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Swarmers
haploid vegetative cells, motile that can form a new lorica and become a new radiating colony
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Pheromones
Gametes coming together is stimulated by pheromones (chemical that stimulates reproduction); erogen released by female to attract the male
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Epilimnion vs Hypolimnion vs Metalimnion
Epilimnion: live at the surface of the lake, well illuminated, those that are photosynthetic (autotrophs)
Hypolimnion: at the bottom of the lake
Metalimnion: intermediate layer, allows for both light and higher nutrient level, best of both worlds, facultative heterotroph found here due to capturing the dying algae that are sinking towards the bottom of the lake= Metalimnion Blooms
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Brown Tides
-Aureococcus (brown algae) causes “brown tides” in coastal waters where causes decline in sea grass (due to shading) and scallops (interference with filter-feeding)
-Abundance causes shade (prevents light from shining down into the water) to other plants and they die
-No toxicity, not like blooms
-Humans not affected by the brown tides
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Physodes
-Inside Phaeophyceae cells are physodes (vesicles)
-Are colourless and absorb UV light, but when exposed to air they turn from colourless to brown or black
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