Midterm Flashcards
Compare these 2 diatom types (centrics and pennates) based on the following characteristic:
- marine or freshwater? phytoplankton or benthos?
- Centrics: Primarily marine phytoplankton.
- Pennates: Freshwater (primarily) and marine, phytoplankton and benthos
Describe this algal storage product: Glucose.
- How is it produced? Is it used immediately or stored, and how?
- Produced by dark fixation of CO2 and energy products of light reactions (photosynthesis)
- May be used immediately to meet energy requirements of the cell
- Organism may store into glucose polymers (High molecular weight compounds or Low molecular weight compounds)
Xenic
presence of foreign organism in a culture
- good exam question *
Compare these flagella types: isokontous, heterokontous, haptonema.
- Isokontous: Flagella (more than 1) that are similar in length and type.
- Heterokontous: Dissimilar flagella (more than 1), of unequal length, and/or one smooth and one hairy (“tinsellated”).
- Haptonema: Superficially resembles flagellum but different internal anatomy (no 9+2 microtubular structure).
- function uncertain but may be used for defence, food capture, or attachment.
- exclusive to Division Haptophyta.
Algae are distributed in virtually every environment on earth. In terms of aerial/terrestrial environments, define this possible habitat:
- Epixylon
On wood surface (ie. wet tree)
Describe what Beta-methylamino-L-alanine (BMAA) is, which is produced by cyanophyta.
- Effects?
- Where is it produced/how?
- What is a population of interest in studying this, and why?
- An amino acid that can be incorporated into the body.
- Research says BMAA may be connected to degenerative nerve diseases like ALS, Alzeimer’s, and Parkinson’s.
- BMAA is produced by cyanobacterial endosymbionts of cycad roots in Guam.
- Connection with neurodegenerative diseases and BMAA studied in Guam where incidence is 50-100x higher, BMAA biomagnifies and is eaten by the Chamorro people in Southeast Asia.
- Cyanobacteria produces toxin, calculates in the cycad/cyano symbiosis, eaten by flying foxes (huge concentration), and then by the people.
Intercalary or terminal heterocyst
may be intercalary in filament or terminal
if intercalary, heterocysts are spaced at regular intervals
Monophyletic.
Descended from a common evolutionary ancestor (a single line of evolution) and are all related.
Diffuse growth in brown algae
- thallus growth
- new cells produced throughout the thallus (anywhere in body)
Describe this general feature of algae:
- Unicellular reproductive structures.
- In the rare cases where the structures are multicellular (they reproduce sexually), there is no distinction (or specialization) between fertile and sterile plants.
- exam
Define: Tinsel flagellum
Tinsel flagellum: Hairy flagella (like tinsel on xmas tree).
from other flashcards:
covered in tubular hairs (mastigonemes), used for motility and for capturing food
In algal morphology, a species can be palmelloid (also colonial); define this.
- Cells are all in one plane (flat plane) in a colony or coenobial, almost 2D.
Compare these 2 diatom types (centrics and pennates) based on the following characteristic:
- raphe present? motility?
- Centrics: No raphe (nonmotile when vegetative). Motile spermatozoids with single flagellum (not heterokont).
- Pennates: Raphe may be present (gliding motility by mucilage). No flagellated spermatozoids
Describe this type of projectile in the division chrysophyta (classes synurophyceae and chrysophyceae): Muciferous bodies
Contain granular mucilage bounded by single membrane
When discharged, contents form fibrous network outside the cell
If a chloroplast membrane has ___ membranes, what kind of endosymbiosis did it go through (primary or secondary)?
- 2 membranes:
- 2 or 4 membranes:
- 2 membranes: primary
- 2 or 4 membranes: secondary
In algal morphology, a species can be filamentous, more specifically, uniseriate; define this.
Has a single chain of cells.
Polyploid
multiple copies of each individual gene
Describe asexual reproduction in diatoms. Not mechanism, just the result and why this mechanism must be used.
- Size of vegetative cell is constrained by frustule (silica, can’t grow or stretch); cell can only grow by adding cingular plates and elongate in the girdle axis.
- Product of asexual reproduction are two dissimilar daughters where one is same size as parental epivalve and other is same size as parental hypovalve.
- Implication is that with successive generations, an increasing proportion of population is smaller than the original parent
pneumatocyst
- Also called air bladder or floats
- Like a beach ball, filled with air, holds the plant at the surface of the water
- An expanded area of thallus containing gases for buoyancy in phaeophyceae (brown algae)
Describe this feature of diatom frustule ornamentation: Striae.
- basic, the other words are on their own cards.
- Lines on surface of valve
- Little distinct rows of dots (at low magnification it looks like a line)
- Contains shallow depressions called areolae in which are smaller pores/slits called punctae.
- More heavily silicified ribs between rows of striae are costae
Describe this method of non-flagellar movement: Euglenoid movement.
What division has this?
- Exclusive to Euglenophyta
- Due to contraction and expansion of pellicular bands
- Cause unknown, may be associated with cytoplasmic streaming
alginate (which group?)
- sugar that retains or absorbs water and forms a viscous material
- thickeness varies between species
- outer, slimy, amorphous
- part of the cell wall in brown algae/ phaeophyceae; protects against desiccation, pounding waves, temperature changes, and salinity
- absorb 300X their weight in water (hygroscopic polysaccharide), used as a thickening agent in shampoo, cosmetics, food
Neurotoxins vs Hepatotoxins
Neurotoxins: affects muscles, functioning of the brain, effects on memory, communication, walking, outcome usually death
Hepatotoxins: affects the liver
List 4 new technologies that were developed post 1950’s that advanced our knowledge of algae.
- Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM).
- Electrophoresis.
- Chromatography.
- Radioisotopes.
Describe this ultrastructure (type of cell) in terms of DNA, nucleus, and organelles.
- Eukaryotes
Chromsomes (+ histones)
Nucleus and organelles present
Define (basic) this diatom frustule ornamentation in terms of:
- Araphidinate:
- Monoraphidinate:
- Araphidinate: no raphe on either valve
- Monoraphidinate: raphe on one valve
What is the usual range for algal life in terms of temperature and pH?
<0C to >40C, but up to 70C. Are alive below 0! Not just frozen.
pH <2 to >10.
Diatoms can be phytoplankton or benthic.
There are 2 subgroups of benthic diatoms, describe:
Epipelon.
- epipelon/epipelic: associated with mud/sediment.
- diurnal: changing over the course of the day
- algae migrate to the surface of the mud and water to be exposed to sunlight (increased photosynthesis)
- Move back into the mud at night to escape from predators by burrowing down into the mud (triggered by sunlight), more nutrients deeper in the ground as well.
Describe the cell covering of division chrysophyta (synurophyceae and chrysophyceae) in terms of:
- 2 types of scales (materials)
- What kind of symmetry would be found in each group.
- Chrysophyceae – radially arranged without clear pattern
- Synurophyceae – bilateral with multiple parts (dome, shield, bristles/spines), precisely arranged in pattern
Cyanobacteria can be halophiles, what does that mean?
salt loving
How do cyanobacteria store polysaccharides?
Store polysaccharides as cyanophycin granules or myxophycean starch (α-1,4 linked glucans do not react to iodine to give blue-black colour)
Parenchymatous
Mass of cells produced by division in three planes, forming solid axes, blades or complex thalli with specialized regions
Pigment
Molecule that absorbs light.
Estuary
where salt water and fresh water flow in together
Encystment vs Excystment
Encystment: to create a cyst or go into a cyst state
Excystment: coming out of a cyst
There are 4 major historical stages of phycology. Describe 4 of 4:
- Early 1950’s to present.
- Why did most of our algae knowledge come in the last ~70 years?
Much better microscopes and techniques used to study algae.
Terra-forming
to create a habitable environment (create life form on another planet)
Chromophyta can be thalloid, in the context of this division, what would that mean?
Thalloid – cells united in pseudoparenchymatous plate-like thallus
- exam
Describe each word in the pair as they pertain to the subject matter of this course, and explain the difference between them.
Sporophyte / Gametophyte
Both are part of the haplodiplontic lifecycle of algae.
A sporophyte is the diploid stage that produces spores from which the gametophyte arises.
The gametophyte is haploid and gamete producing.
*From notes exactly: Haplodiplontic (diplohaplontic): alternation of generations between gametophyte (gamete-producing generation) and sporophyte (spore-producing generation) stages.
Swarmers
haploid vegetative cells, motile that can form a new lorica and become a new radiating colony
Describe in general, the chloroplasts of diatoms in terms of:
- How many chloroplasts (and what structure) are present in centrics vs pennates?
- Centrics: large number of discoid chloroplasts
- Pennates: 1, 2 or 4 plate-like parietal chloroplasts
Describe in general, the chloroplasts of diatoms in terms of:
- How many membranes? What does this say about the endosymbiosis it underwent?
- Continuous or discontinuous ER?
- Surrounded by four membranes (secondary endosymbiosis)
- Chloroplast ER is continuous with outer membrane of nuclear envelope
Peripheral chloroplast
A chloroplast that goes around the cell
When did the first heterotrophic or chemosynthetic autotroph appear?
When did the first prokaryotic algae appear (cyanobacteria)?
When did the first eukaryotic algae appear?
- 3.5 billion ya.
- 2.7 billion ya.
- 1.5 billion ya.
Describe this modified plasma membrane (algal cell covering):
- Thecal plates.
- What division has it?
- Interior or exterior?
- Exclusive to Dinophyta (dinoflagellates)
- Vesicles below membrane contain unknown fibrillar compound (non-cellulosic) below which are microtubules
- Vary in size from nonexistent to thin to thick
- Internal, under cell membrane
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
Chromophyta can be unicellular, in the context of this division, what would that mean?
Unicellular – free-living with flagella
Gonidia is another name for ____.
Akinetes.
haplontic lifecycle
Predominantly haploid lifecycle (1 copy per gene) but has a short-lived diploid zygote stage.
Chloroplasts of Euglenophyta and Dinophyta have ____ membranes.
Chloroplasts of Euglenophyta and Dinophyta have three membranes.
Describe this modified plasma membrane (algal cell covering):
- Periplast.
- Interior or exterior?
- outside plasma membrane are granular fibrils, while inside are hexagonal or rectangular plates of protein interrupted by ejectosomes.
- Interior.
Define (basic) this diatom frustule ornamentation in terms of: Raphe
Can all diatoms have this?
- 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
There are 2 theories of how eukaryotes formed.
Describe: The autogenous theory.
- Evidence?
Autogenous theory:
- “self-creating” (from pre-existing materials)
- Eukaryotes evolved through step-by-step changes in photosynthetic, respiratory and genetic units (slow and gradual)
- Gradual compartmentalizations and specialization of function
- Probably explains occurrence of nucleus, mitotic apparatus, and flagella
Phycology/Algology:
- What is the word derived from?
Derived from Greek phycos for seaweed (Latin fucus=seaweed).
Describe flagella in algae.
- Vegetative cells, composed of 9+2 microtubules (9 pairs of microtubules around a central core).
- Vary in number from 1 to >100 per cell.
- Most common in unicellular eukaryotes freely suspended in water have them, but may be present in some algal lifecycle stages only (zoospores).
What does NADS stand for?
North American Diatom Symposium
Chlorophyll (used to produce what, what colour of light it absorbs and reflects, do all algal groups have it?)
- 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, or f
Intercalary vs terminal heterocyst
may be intercalary in filament or terminal
if intercalary, heterocysts are spaced at regular intervals
Compare these 2 diatom types (centrics and pennates) based on the following characteristic:
- differences from normal type of reproduction (asexual and sexual), and are they oogamous or isogamous?
- Centrics: Form resting cells (or cysts). Oogamous sexual reproduction (large, nonmotile egg and smaller, motile sperm).
- Pennates: No flagellated spermatozoids. Sexual reproduction by isogamy (conjugation, 2 similar gametes)
Compare these 2 classes (synurophyceae and chrysophyceae) in division chromophyta in terms of….
- Chlorophyll C2 present (yes or no)
- Synurophyceae: no
- Chrysophyceae: yes
Describe differences occurring in mitosis in mesokaryotes.
- No interphase (continuous DNA synthesis)
- Nuclear membrane persists during mitosis
- No microtubules laid down during nuclear division)
Algae can store glucose as a high molecular weight compound. There are 3 types of a-1,4 linked glucans, describe: True starch.
- What does it contain
- How it would stain with iodine
- Where it would be found (algal type and location)
- Contains amylose and amylopectin.
- Stains purple with iodine.
- Found in Chlorophyta (only algal group where starch stored inside chloroplast rather than cytoplasm).
Algae can store glucose as a high molecular weight compound. There are 3 types of B-1,3 linked glucans, describe: Laminarin.
- What form is it, and where is it stored?
- What 2 algal groups would have it?
Oil-like liquid stored in vesicle around pyrenoid.
Found in phaeophyta and chromophyta.
What is phenetic classification?
Use of physical appearances, morphological, biochemical, and physiological features to classify into different groups .
Define: Symbiont
two organisms in close association with each other
Chromophyta can be colonial, in the context of this division, what would that mean? (how are they linked)?
Colonial – number of flagellates linked
Uniseriate vs Multiseriate
Filamentous (thread-like) usually composed of single rows of cells (uniseriate) and sometimes several rows (multiseriate)
Define (basic) this diatom frustule ornamentation in terms of:
- Biraphidinate:
- Pseudoraphidinate:
- Biraphidinate: raphe on both valves
- Pseudoraphidinate: clear area in centre of valve without fissure
Define: Heterocyst in terms of…
- Their function.
- When more would be produced.
- Do they use oxygen?
- Thought to function in nitrogen fixation; the further away from the heterocyst, the lower the nitrogen concentration; distance between heterocysts indicates the concentration of nitrogen in the environment; product diffuses to neighbouring cells, with less going to cells farther away.
- Produced in low nitrogen environments (number indicates how low nitrogen the environment is).
- They are anoxegenic (since nitrogen fixation is negatively affected by oxygen, it creates an anaerobic zone).
Are heterocysts a prerequisite for nitrogen fixation?
Heterocysts are NOT a prerequisite for nitrogen fixation
First photosynthetic organisms with two photosystems producing oxygen as product (first oxygenic autotroph) = ______.
Cyanophyta
List 5 socio-economic effects or uses for diatoms.
1. Toxins 2, Symbioses 3. Environmental indicators 4. Industrial applications 5. Forensic investigation
phagotrophy (super basic)
ingestion of solid particles
Beta-methylamino-L-alanine (BMAA) is produced by what algal phyla?
cyanophyta
Algae are distributed in virtually every environment on earth. In terms of aerial/terrestrial environments, define this possible habitat:
- Symbioses.
Live with something else, like lichens = fungi + algae
Algae are distributed in virtually every environment on earth. In terms of aquatic environments, define this possible habitat:
- metaphyton.
metaphyton = between plant —> formally attached
Starts living on a plant (epiphytic) but becomes so numerous that it detaches and falls off, then called metaphytic.
“elephant snot”
Chromophyta can be coccoid, in the context of this division, what would that mean?
Coccoid – spherical or elliptical, non-motile cells surrounded by walls, sometimes in colonies
Lamellae
Thylakoids grouped in three, in chloroplasts.
- Diatoms have this
Compare these 2 classes (synurophyceae and chrysophyceae) in division chromophyta in terms of….
- Symmetry/patterning of scales
- Synurophyceae: Bilateral symmetry with pattern
- Chrysophyceae: Radial symmetry with no pattern
What is mucilage made of?
A gelatinous material produced by algae and composed of water, polysaccharides, and protein.
Are diatoms motile yes or no?
no, no flagella
Describe cysts as diatom reproduction.
- Formed within vegetative cells (usually marine centrics)
- Thick-walled, maybe spherical, dissimilar to vegetative cell
- Under appropriate environmental conditions, cyst enlarges and develops two valves larger in size than parental ones
- Another means of restoring population size
Prokaryotes have ___ thylakoids in cytoplasm.
free
Algae are distributed in virtually every environment on earth. In terms of aerial/terrestrial environments, define this possible habitat:
- Epilithon.
On rock surfaces.
Define: Zoospore (planospore).
A motile stage of asexual reproduction.
Pigmentation in chromophyta (diatoms): 3/4 main.
Chlorophylls A, C, Carotenoids (very abundant, particularly fucoxanthin, which masks green colour of chlorophylls)
Algae are distributed in virtually every environment on earth. In terms of aquatic environments, define this possible habitat:
- periphyton.
attached to any surface (animal, rock, plant)
Define: Biomagnification (and an algal toxin that biomagnifies).
As it goes up a food chain, the higher the concentration of the toxins gets in each stage.
Define:
- Punctae (Punctum=singular)
- Areolae (areolum=singular)
- Diatom frustule components, specifically, part of striae.
- The striae contains shallow depressions called areolae in which are smaller pores/slits called punctae.
Define: Heterocyst in terms of…
- Where might one be found?
- How does it differ in appearance from vegetative cells (what about if they’re intercalary)?
- Found only in some filamentous Cyanophyta
- 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; if intercalary, heterocysts are spaced at regular interval.
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
List 5 ways that cyanophyta reproduce asexually. Can they reproduce sexually?
- Binary fission.
- Trichome fragmentation.
- Germination from akinetes.
- Germination from hormogonia.
- Endospores and exospore.
- no evidence of sexual reproduction.
Define: Thylakoids.
Flattened membrane bound sack where pigments occur for photosynthesis.
where most brown algae live
Vast majority are marine
and other substrata in inter freshwater species (4 genera)
and live attached to rocks and other substrate in the tidal zone; which is shallow/near shore so they can get enough light. Not so much in the open ocean, but can be in kelp forests which are a bit farther from shore.
What kind of lifecycle do diatoms have?
Diplontic, but gametes are haploid
Able to switch between auto and heterotrophy
mixotrophy
Algae are distributed in virtually every environment on earth. In terms of aquatic environments, define this possible habitat:
- neuston.
live on the air-water interface (like right on surface crust of water)
Mixotrophy
- can switch accordingly back and forth between autotrophy and heterotrophy.
- lots of light = photosynthetic
- no sun = heterotrophic.
- Grow faster when they’re autotrophic.
Some suggest phylogenetic affinities based on photosynthetic pigments.
Describe the phycobilin series in terms of:
- What 2 similarities are present between the members of the group (Cyanophyta, Rhodophyta, Cryptophyta)?
- Red algal chloroplasts resemblemble cyanobacteria with pigments associated with a single membrane.
- No motile stages in lifecycles
what’s Prochloron (Prochlorophyta) and what is the significance?
- discovered 1975 by Ralph Lewin (*loves him but maybe not critical)
- Thought by many to be an intermediate form between prokaryotes and eukaryotes:
- Prokaryotic
- No phycobilins
- Chlorophyll B in addition to chlorophyll A
- Thylakoids stacked in pairs, not monolayers
most common morphology and flagella in: chrysophyceae
Unicellular or colonial
Two unequal flagella
If the classification name of an algae ends with _____, which hierarchical level is it?
- phyta
Division.
Describe this method of asexual reproduction in algae.
- cell division or binary fission.
- Simple cell division (most primitive.
To summarize Lee’s classification, there are 4 main algal groups.
- Eukaryotes with 2 chloroplast membrane:
- 3 divisions.
Divisions Glaucophyta, Rhodophyta, Chlorophyta.
Brown Tides + which group causes them
*skipped slide so not priority
-Aureococcus (chrysophyta) causes “brown tides” in coastal waters where causes decline in sea grass (due to shading) and scallops (interference with filter-feeding)
What is numerical aperture?
The ability to see two discrete objects (with poor N.A. you will only see one object).
List 4 new technologies that were developed post 1950’s that advanced our knowledge of algae.
- Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM).
- Electrophoresis.
- Chromatography.
- Radioisotopes and stable isotopes.
in the sexual reproductive cycle of dinobryon (chrysophyte), are they monoecious or dioecious? iso, aniso, or oogamous?
- Dioecious (Male and female)
- Anisogamous
4 types of meristems (phaeophyceae)
- Apical=at ends/tips of branches
- Intercalary=within branches; may be transitional between fronds and stipe
- Trichothallic=at base of terminal hair (filament)
- Meristodermal=region located on thallus surface (increases girth)
In algal morphology, a species can be filamentous, and may be “true or false”; define this.
True branching is when the alga grows in a new plane (second plane).
False branching is when serrate algal may get stuck together and appear branched but aren’t (ie. caught together by a common coat of muscilage).
Describe this accessory pigment: Phycobilins
- Colours (name of them)
- The 3 phyla they’re exclusively found in
- Red or blue-green.
- Phycoerythrin (red).
- Phycocyanin (blue-green).
- Pigments found exclusively in Cyanophyta, Cryptophyta, and Rhodophyta
List the 4 general features of algae.
- No differentiation of parts.
- Vegetative reproduction is common.
- Unicellular reproductive structures.
- Zygote germination (if sexual).
Define: Chromatic adaption.
Algae modify pigment content for environment.
Define: Extremophile
Organisms that love extreme conditions
Chromophyta can be amoeboid, in the context of this division, what would that mean?
Amoeboid – naked cells with pseudopodia
Dianoflagellates have long spines, what is the most likely use for them?
- To increase surface area and to allow them to float better/sink less - spines are rarely for protection.
When did the first eukaryotic algae appear?
- 1.5 billion ya.
Of the 5 eukaryotic supergroups, 3 of them contain algae. List the names of these supergroups.
- Excavates
- Chromalveolates
- Plantae
Describe the diatom frustule structure in terms of:
- Cingulum/cingular bands/girdle
- separates the epivalve and hypovalve of the frustule in Diatoms
____ is a specialized cell produced by some cyanobacteria that is thought to be the site of nitrogen fixation.
heterocyst
Describe this algal flagella type:
- Isokontous.
Isokontous: Flagella (more than 1) that are similar in length and type.
Tinsel vs Whiplash Flagellum (ex. in chrysophytes)
- 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
Chlorophyl absorbs light in the range of __nm (___) to ___ nm (___).
* number and colour
400 (blue) to 700 (red).
Statospores (sometimes called Cysts) in chrysophytes.
- formation is included but not necessary for this card, just to review it.
- 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
Compare these 2 classes (synurophyceae and chrysophyceae) in division chromophyta in terms of….
- Eyespot present (yes or no)
- Synurophyceae: no
- Chrysophyceae: yes
Despite morphological and biochemical differences, it is thought eukaryotic algae are descended from _____ ______.
Despite morphological and biochemical differences, it is thought eukaryotic algae are descended from autotrophic prokaryotes.
“Phyta” vs “Phycos”.
Phyta - plant.
Phycos - algae.
To summarize Lee’s classification, there are 4 main algal groups.
- Prokaryotes:
- 1 division (includes ____).
Division Cyanophyta (includes Prochlorophyta).
Cyanobacteria are highly adaptable and can live in soil. What are some of their roles in soils (including any things they contribute to soil (2), how their mucilage affects it, and crusts).
- N-fixers are potential source of soil nitrogen
- Provide initial organic matter in primitive soils, may be first to colonize after something happens
- Mucilages bind soil, reducing erosion
- Crusts help to retain moisture (looks like a brain, they’re adapted for drier environments)
In algal morphology, a unicellular species can be coccoid, what does this mean?
A spherical cell, the same shape all around.
If you see these features, how can you know which class of division chrysophyta it is?
- Contractile vacuole (water pump) on same side of cell as flagella
- Flagella are perpendicular (heterodynamic)
- Heterokont (2 dissimilar flagella) = whiplash and tinsel
- Granules at base of flagella
- Eye spot
- Contractile vacuole (water pump) on same side of cell as flagella = chrysophyte (NOT synurid)
- Flagella are perpendicular (heterodynamic)
- Heterokont (2 dissimilar flagella) = whiplash and tinsel
- Granules at base of flagella
- Eye spot in chyrsophyta (not in synurid)
Scale symmetry of Chrysophyceae
- Chrysophyceae – radially arranged without clear pattern
Describe this modified plasma membrane (algal cell covering):
- Cell wall.
- Can they be incomplete? What is this called?
-Usually complete but may be incomplete, such as lorica in some Chrysophyta and Euglenophyta
Seven Pillars of the BMAA-ALS Hypothesis
- Cyanobacteria produce BMAA
- BMAA exposure is ubiquitous
- BMAA can be inserted into proteins
- BMAA can be biomagnified within ecosystem
- BMAA is neurotoxic to motor neurons
- Individuals vary in vulnerability to BMAA
- BMAA occurs in brain tissue of ALS and Alzheimer’s disease patients but not health controls
Physodes (+which group)
- Vesicles in cytoplasm of phaeophyta associated with chloroplast
- Contain colourless, highly refractive polyphenolic compounds such as tannins
- Are colourless, highly absorptive of the UV light to protect the cell, the algae live in shallow water where ultra-violet light is more abundant at the surface compared to going deeper in the water
What kind of xenogenous development did euglenophyta have?
incorporated chlorophyl from eukaryotic green algae (ingested it as food)
Which 3 algal groups have chlorophyll B, in addition to A?
Prochlorophyta, Chlorophyta, Euglenophyta
Meristematic and Meristem
new cells produced in specialized area called meristem (cells that are rapidly dividing)
Describe this ultrastructure (type of cell) in terms of DNA, nucleus, and organelles.
- Prokaryotes
Coiled DNA (no chromosomes)
No nucleus
No organelles
Describe this algal morphology: Unicellular.
Just a single cell.
Define: Vacuole (function, where it’s found).
- An organelle that functions in storage of waste and nutrients.
- Found in eukaryotic algae.
How do diatoms get their nutrition? 3 main types.
- Most are photolithotrophic and store photosynthate in the form of fats, oils, and
chrysolaminarin, BUT very hard to grow in lab, indicating that they’re most likely auxotrophic – require one or more organic nutrient (e.g., vitamins) that they can’t make themselves. - Some are mixotrophic (facultatively heterotrophic), can switch between autotrophy or heterotrophy.
- A few are obligately heterotrophic (colourless).
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
Pheromones
Gametes coming together is stimulated by pheromones (chemical that stimulates reproduction); erogen released by female to attract the male
What 3 algal divisions may have naked plasma membranes (no cell covering)? Are there situations where other ones may have this?
- Found in some members of Chromophyta, Chlorophyta, -
and Rhodophyta.
- Some reproductive stages may have naked membranes
Trichome vs filament.
Trichome: linear chain of cells, that are not surrounded by a mucilage coat.
Filament: a linear chain of cells surrounded by a mucilage.
*trichome + mucilage sheath = filament
In what ways are cyanobacteria similar to plants? 3 main reasons.
Chlorophyll A is primary photosynthetic pigment (no bacteriochlorophyll or chl B)
Have phycobilins (phycoerythrin and phycocyanin) like Cryptophyta and Rhodophyta
Oxygenic photosynthesis
Holdfast
- Parts of the plants that resemble roots but not true roots, can wrap around rocks ad other plants, anchors the plant
- Is the modified basal region for substratum attachment in phaeophyceae (brown algae)
Describe this method of non-flagellar movement: mucilage secretion.
What divisions have this?
- Slime trail
- Found in Bacillariophyceae (diatoms) and desmids
- Mucilage may be secreted from frustular pores (in diatoms)
Some suggest phylogenetic affinities based on photosynthetic pigments.
Describe the non-masked series in terms of:
- Which 3 groups are part of it?
-Chlorophyta, Euglenophyta, Xanthophyta
Algae are distributed in virtually every environment on earth. In terms of aerial/terrestrial environments, define this possible habitat:
- Sympagic.
Inside ice (not frozen, living and photosynthesizing). Word means “with ice”.
What are binomial systems for naming?
Genus + specific epithet, a naming system used for algae.
Is algae classification monophyletic? If not, how is it classified?
No, algae classification is phenetic.
Describe this of nutrition in chrysophyta (classes synurophyceae and chrysophyceae): Phagotrophy
- What they eat, mechanism, how much/how fast they can eat.
Ingestion of solid food particles such as bacteria, yeast, small eukaryotes into food vacuole of pigmented or non- pigmented chrysophytes and synurids
Some taxa obligately phagotrophic (e.g., Ochromonas spumella)
Mechanism:
- Particle seized by tinsel flagellum and taken in as a food vacuole.
- Ingestion complete within 2-3 seconds of contact and up to 3 bacterial cells ingested per 5 minutes
Describe this method of non-flagellar movement: Gliding.
What division has this?
- Slow, gliding motion
- No visible organ responsible
- May be due to regularly arranged fibrillar extensions of the protoplasm
- Found in Cyanophyta
Describe chloroplasts in division chrysophyta (classes synurophyceae and chrysophyceae) in terms of:
- how many thylakoids per stack (and what is this called)?
- are pyrenoids common or no?
Thylakoids stacked in threes (lamellae)
Pyrenoids common in chloroplast
What’s diatomite and what are some uses for it?
- Diatomaceous earth (diatomite), produced by diatoms.
- Mined from deep deposits of mostly marine origin
- Diverse commercial uses:
Abrasives (polishes, toothpaste)
Filtration
Absorbents (cat litter) Insecticides
Brewing alcohol
Whorls of branches
branches coming off one point and radiating into all directions
