Exam 1
gametic meiosis (pg. 254)
Meiosis resulting in the formation of haploid gametes from a diploid individual; the gametes fuse to form a diploid zygote that divides to form another diploid individual.
3. Discuss the advantages and disadvantages of multicellularity.
better predator, lower fitness
Discuss the endosymbiotic hypothesis regarding the origin of eukaryotic organelles; What role do cyanobacteria have in this hypothesis?
every choloplast that plants and algae have were originally cyanobacteria. through phagocytosis: organism wraps a membrane around in order to bring a particle to digest it. Archeaplatida(orgin/ancient-chloroplasts): were ingested by a eukaryotic cell(glaucophytes:15 species, not well studied, primary endosymbiosis) and became chloroplasts.
gametic life cycle
gametes are the only haploid cell, and they can either syngamy or die
Green algae traditionally are referred to the taxonomic group "Chlorophyta". Why specifically does your textbook avoid giving this group a formal taxonomic name?
not monophyletic
Contribution of photosynthesis
o2 production, co2 removal
8. Discuss the three-fold value of understanding the life cycle of an organism.
1) differences in reproductive structures are important clues for identification 2) life cycles aid in understanding "weak points" for biological control 3)life cycles affect genetic variation important for conservation decisions as well as adaptation by organisms to changing environments.
blade,
(1) A leaflike structure of a algae that provides most of the surface area for photosynthesis.
What are the Archaeplastida and what is the significance of this name
(Archae=ancient plastida=chloroplats) -clade of glaucophytes(15 species), red algae (monophyletic), green algae(not monophyletic, common ancestor of green algae is the common ancestor of plants) & plants. -have chloroplasts because of primary endosymbiossis -macroscopic red and green algae
coccoliths
(Caco2) Calcium carbonate scales that surround coccolithophores for protection
Haptophyta
(Haptophytes; hapto = to fasten) These primarily marine algae received their chloroplasts via secondary endosymbiosis of a red algal cell, and, like red algae and cryptomonads, some species thrive in water more than 200 meters deep. Many species possess a thread-like cell extension called a haptonema that can hold prey or food particles. - Many haptophytes produce external body scales of calcium carbonate called coccoliths; sedimented coccoliths are the major contributor (25%) of ocean floor limestone deposits and thus haptophytes are extremely ecologically important in the carbon cycle. Other species produce large quantities of sulfur containing molecules that are important in cloud formation, acid rain, and climatic cooling. -Mixotroph: photosynthesize and eat things thru phagocytosis -Haptonema -300 species -have a different morphology with cocoliths(no one knows how these form) -have chlorophyll a & c
haptonema
(To fasten- hapto, thread=nema) Unique structure arising from the cell surface between the 2 flagella, captures food, whips it arougn and then the membrane covers it.
Phycocyanin
(algae-blue) clorophyll main pigment
Phaeophyceae
(brown algae; phaeo = brown) Brown algae are stramenopiles and share a common ancestor with diatoms. Some brown algae are small filaments, but most are larger with leaf-like blades, stem-like stipes, and root-like holdfasts. None are unicellular, so this group does not contain any phytoplankton. Some are over 180 ft long, and even have specialized cells for transporting food from the blades to the holdfasts. Most have tiny plasmodesmata or channels that connect the protoplasm from adjacent cells. Brown algae include the kelps and most common seaweeds of cold, temperate waters. Algin, derived from the cell walls, is used similarly to agar and carrageenan (from red algae, see below) in food and industry. Some brown algae have sporic meiosis with an isomorphic alternation of generations. Others have heteromorphic generations with microscopic gametophytes. Yet others have gametic meiosis and do not alternate between generations (pg. 254;338-339). -fucoxanthin: pigment, give it the brown color -1500 species, -marine only -pigments: CHL A&C, fucoxanthin -walls made of cellulose, which is surrounded/embeded in an algal matrix -no unicellular brown algae
Bacillariophyceae
(diatoms; bacillium = rod) Diatoms have the greatest biomass and species diversity of all phytoplankton in marine and fresh waters. They account for up to 25% of the total primary productivity on earth, and are the single most important component of aquatic food chains. Diatom cell walls consist of two frustules made of silica, one that overlaps the other. -Reproduction is both asexual and sexual (gametic meiosis), with pennate diatoms having isogamous gametes and centric diatoms with oogamous gametes. Large deposits of diatomaceous earth (diatomite) are industrially important and provide evidence of the vast numbers of these microscopic cells. Because diatoms divide rapidly and are immersed in their surroundings, they are good indicators of ecological conditions; pollution or nutrients released today will impact numbers observed tomorrow. Diatoms are 'Stramenopiles' and share a common ancestor with brown algae and some other groups.
Euglenoids
(eu = true, gleno = eye) Many species of euglenoids are strictly heterotrophic. One-third have green chloroplasts derived from secondary endosymbiosis of a green algal cell(has 3 membranes around cholophlasts, and no nucleomorpht). Euglenoids thrive in nutrient rich water, such as those associated with decaying organic matter, and are often used as environmental indicators of such conditions (primarily fresh water, but some marine). Reproduction is by cell division (mitosis). -Have contractile vacuole: fresh water to control salinity of the cell, it gets water out of the cell. -stigma(mark or spot): has a molecule in it called a -cryptochrome: molecule that senses light, used in humans for sight, this organism uses it to put itself in the best sspot in the water column (ie. if its too high, it'll move down and vis versa if its too low) -2/3 don't have chloroplasts, means they have to use phagocytosis for nutrients. -800-1100 species -have chlorophyll a+b -asexual reproduction: mitotic division -no rigid cell wall -mostly freshwater
Chlorophytes
(green algae; chloro = green). The green algae are diverse in size, shape, and reproductive life cycles, with important phytoplankton representatives and important macroscopic species. Green algae are commonly encountered in both marine and freshwaters; a few are primarily terrestrial and some form important symbiotic relationships with lichens. Many green algae have zygotic lifecycles, though some have evolved sporic lifecycles. Some green algae are used as food, and others have contributed significantly to some petroleum deposits. Most significantly, evidence indicates green algae are the group from which the plant kingdom evolved, and these two groups share many features (pg. 367). -common ancestor also gave rise to plants=paraphyletic group -17,000 species -unicellular, colony forming, multicellular, and macrocellular groups -some don't have to be in water all the time, some work with fungi, they are also in freshwater and marine water -most have zygotic lifecycles, some with sporic -pigments. CHL A&B, like eugliods and plants -store starch in chloroplasts, like plants -Cue: decreasing nutrients
Phytoplankton
(phyto = plant, plankton = wanderer). Phytoplankton encompass the unicellular and unicellular colonial organisms that form the base of aquatic food chains; most groups of algae have at least some species that would be classified as phytoplankton. Cyanobacteria are an important phytoplankton component, but here the focus is only on the eukaryotic groups. Listed below are algal groups composed entirely or primarily of unicellular or unicellular colonial members. Note that in many cases, these groups are not closely related. Some groups have formal taxonomic names (in parentheses, Table 15-1) implying monophyly of those groups, while monophyly of others is uncertain at present.
. Rhodophyta
(red algae ; rhodo = red) Red algae share common ancestry with Green algae (see below)—unicellular species are ancestral in both groups, so multicellularity evolved independently. The red algae are mostly multicellular and predominantly marine. They are unique among algae in lacking flagella at any stage of the life cycle, and in possessing chlorophyll A as its only chlorophyll molecule. While accessory pigments help some algae protect themselves from too much sun, the phycobolins of red algae absorb the higher energy blue and green wavelengths that penetrate deep water. This enables some red algal species to inhabit water up to 800 ft. deep (deeper than any other algae) where light intensity is only 0.0005% that of surface light. "Coralline algae" accumulate calcium compounds on their walls; some of these are important contributors to reef building. Bio 230: Algae (etc) Study Guide 5 Reproduction can be both asexual or sexual, with some sexual cycles including three generations (1 haploid, 1 diploid attached to the haploid gametophyte, and 1 free living diploid sporophyte). Some red algae are eaten directly in eastern countries, and the cell wall components agar and carrageenan are used in food and industry worldwide -4000-6000 species -few fresh water, mostly tropical marine -mostly multicellular -unique in they have no flagella in any stage of life -Unique in they only have chlorophyl A and phycoblins(give red algae their colors, good at absorbing high engergy wave legnths (ie. blue and yellow)) and carotenoids -storage molecule is floridean starch -walls- cellulose with agar (slime it secretes, used in electrophloresis gel) and carrageenan(also slime, used in food to make it smooth, like BYU's chocolate milk)
Diatoms can reproduce sexually and asexually, but asexual reproduction is most common. What cues are used to stimulate sexual reproduction in diatoms? Which cue is specific to diatoms and which is more general to other unicellular, sexual algae?
-Unique: asexual production going to minimal size will stimulate meiosis (frustule and diatome is too small to sustain life, so the small diatomes begin meiosis) -General: lack of nutrients will make them go into meisosis where they can wait as cysts until they sense that there is sufficient nutrients to complete reproduction
Explain how rain followed by extended periods of hot, sunny weather and calm seas can lead to red tide and the effects of a red tide on other aquatic organisms and humans.
-after a rainstorm(nutrients runoff from the land) -post rain, really sunny day (warm water) with no wind (no mixing=decreased salinity lasts longer, results in dead fish starved of O2) -increased nutriends and lessened salinity=toxic tides
How do reproductive rates, intimacy with their environment, and nutrient needs contribute to the usefulness of phytoplankton as water quality biomonitors?
-unicellular -sensitive to nutrients (Nitrogen, Phosphorous, Potassium) -surface to voume ratio is really large (becasue it is a single celled organism) small organisms have large surface-volume ratio because they use the membrane to get nutrients(this means they are easily affected by nutrients, so they will be affected highly in a rise of nutrients or a drop) -close contact wi/ surroundings -use phytoplankton to meeasure the wealth of aquatic systems are in . -wood is a result of photosyntheis -oil is a result of decomposed plant/photosynthetic life.
glaucophytes:
15 species, not well studied, primary endosymbiosis, became red algae.
CYANOBACTERIA
A (cyano = blue) Cyanobacteria are among the most ancient autotrophs. Through photosynthesis, they undoubtedly influenced the early evolution of many forms of life. Ecology: -bodies of water, anywhere unless it is too acidic -pioneer organisms:add organic material to soil to mke it more fertile -cryptobiotic crists - contributions to the atmosphere
holdfast,
A rootlike structure that anchors a seaweed.
stipe,
A stemlike structure of a seaweed.
is a generic term for autotrophic eukaryotic organisms that produce oxygen as a byproduct of photosynthesis, but lack the defining features of true plants (that is, algae are not part of kingdom Plantae). "Algae" is a functional definition and not a term that describes a monophyletic group of organisms. Cyanobacteria have been called "blue-green algae", but because they are prokaryotes, they are classified in Domain Bacteria apart from all other photosynthetic organisms. Eukaryotic algae belong to Domain Eukarya with various relationships to other organisms in an informal group called protists. Protists are sometimes classified in a formal kingdom Protista, but since this kingdom is clearly not monophyletic, your textbook does not use that formal name, and we will not either. Most importantly, while all algae are protists, not all protists are algae; in fact, most aren't. Within every planktonic group considered below, heterotrophic, non-photosynthetic species also exist that are not algae by definition. Some of the photosynthetic plankton may also obtain nutrients through phagocytosis or osmosis, giving rise to a condition called mixotrophy.
Algae
ALGAE
Algae are eukaryotic protists, primarily aquatic, and likely to be found wherever liquid water and light co-occur. Characteristics used to differentiate between algal groups (Table 15.1) include pigments (chlorophyll & accessory pigments; pgs. 126-129), cell wall composition, number and insertion of flagella, food storage molecules, morphology (shape, structure), and to some extent, habitat. Though neglected in daily thought, algae are extremely important ecologically and economically. Algae are a major component of the base of all aquatic food chains. They have contributed much to the formation of an oxygen rich atmosphere both by O2 synthesis and by removing CO2 that is not immediately available for decomposition (via sedimentation, etc., pgs. 140-141). They have contributed to fossil fuel deposits, limestone, diatomaceous earth deposits, reef building, and toxic tides. Some also are valued for direct human consumption or for byproducts used in food and industrial manufacturing.
What are Algae? To what higher taxonomic group do they belong?
Algae is a generic term for autotrophic eukaryotic organisms that produce oxygen as a byproduct of photosynthesis, but lack the defining features of true plants (that is, algae are not part of kingdom Plantae). "Algae" is a functional definition and not a term that describes a monophyletic group of organisms. -Domain Eukarya
What is a Stramenopile & where does this term come from? What algal groups are Stramenopiles? (note: Heterokonts is an alternative name also used for this group).
Although this group is diverse, they all share a common ancestral trait. Namely, the presence of hair-like projections on their flagella; "stramen" means flagellum in Latin, and "pilos" means hair; hence, stramenopilans. - hetero- hetero- Greek kontos punting pole, goad ( in reference to the pair of flagella ); see kent- in Indo-European roots. -Chrysophyceae -brown algae -diatoms
diploid organism,
An organism that has two copies of its genome it each cell. The paired genomes are said to be homologous. 2n
meiosis
Cell division that produces reproductive cells in sexually reproducing organisms (gametes for gametic or zygotic, or spores in sporic)
When light is absorbed by a photosynthetic pigment, one of thee things can occur— what are these?
Chlorophyll pigments when energized can: -fluorece (release energy) -pass the energy to a neighbor -If they are in the reaction center (A) they can pass it up the electron transport chain which begins the process of phtosynthesis.
Volvox,
Colonial green algae held together in a secretion of gelatinous material, resembling hollow ball
toxic blooms (pg. 323)
Commonly Dinoflagellates (AKA red tides) cant Toxic tides are favored: -after a rainstorm(nutrients runoff from the land) -post rain, really sunny day (warm water) with no wind (no mixing=decreased salinity lasts longer, results in dead fish starved of O2) -increased nutriends and lessened salinity=toxic tides
important food source for zooplankton
Cryptophyta
heterocyst
Cyanobacteria. a large, transparent, thick-walled cell found in the filaments of certain blue-green algae and in certain fungi. They fix nitrogen. cant do it in the presence of oxygen so they have thick walls. They are iin colonies, because they have specialized to produce nitrogen so they need energy from neighboring photosynthetic cyanobacterial.
Chrysophyceae
DON'T WORRY TOO MUCH ABOUT THIS ON THE TEST (golden algae; chryso = gold) Chrysophytes are stramenopiles closely related to Bacillariophyceae and Phaeophyceae, and share a similar golden brown color of chloroplasts. Many are mixotrophic, capable of ingesting food 2-3 times their own size and increasing their volume 30 times their normal size to hold the food they have ingested.
zooxanthellae
Dinoflagellates that live within the tissues of reef corals and other marine animals. -when they are in other animals they lose their theca and live as a cell inside the animal's cells.
Discuss the economic and ecological role of red algae.
Ecological: contribuest to the coral reefs and how deep they grow. The most plant like organsim that is not a plant> Economic: agar gel and careegeenan controls texture in foods.
Define and give an example of secondary and tertiary endosymbiosis with details and evidence supporting these hypotheses.
Euglenoids: One-third have green chloroplasts derived from secondary endosymbiosis of a green algal cell(has 3 membranes around cholophlasts, and no nucleomorpht). Dinoflagilattes: tertiary endosymbiosis, 4 membranes
gas vesicle
Gas vesicles occur primarily in aquatic organism as they are used to modulate the cell's buoyancy and modify the cell's position in the water column so it can be optimally located for photosynthesis or move to locations with more or less oxygen.
agar,
Gelatin-type material derived from seaweed
Macro algae
Included here are three groups that are not necessarily closely related, but that have at least some large, multicellular species.
Karenia (Gymnodinium)
Karenia brevis is a microscopic, single-celled, photosynthetic organism that is part of the Karenia (dinoflagellate) genus, a marine dinoflagellate commonly found in the waters of the Gulf of Mexico. ... Each cell has two flagella that allow it to move through the water in a spinning motion. Gymnodinium is a genus of dinoflagellates, a type of marine plankton. It is one of the few naked dinoflagellates, or species lacking armor (cellulosic plates).
Are Algae monophyletic? Protists? Explain.
NO. Eukaryotic algae belong to Domain Eukarya with various relationships to other organisms in an informal group called protists. Protists are sometimes classified in a formal kingdom Protista, but since this kingdom is clearly not monophyletic, your textbook does not use that formal name, and we will not either. Most importantly, while all algae are protists, not all protists are algae; in fact, most aren't.
Recognize distinguishing features in form and reproduction of Clamydomonas,
NOT ON EXAM
, Ulva
Not on Exam
Spirogyra
Not on Exam
mixotrophic
Organism that can use autotrophic and heterotrophic means of gaining nutrients. Ie. photosynthesis and phagocytosis
Distinguish between primary and accessory photosynthetic pigments—how do each of these function?
Primary pigment: -Chlorphyll A- in all photo synthetic organisms. passes energy up the electron chain. Look at diagram. Secondary pigments: -chlorophyll B (Evolved in green algae) in green algae, euglenoids, all plants (kingdom plantae) have B. -Chlorophyll C in brown algae, cryptomonads, straminophiles, various phytoplankton -phycoblins -carotinoids(wear mult. hats)
What reliable features may be trusted to distinguish the various algal groups?
Size(2 groups: macro algae or phytoplankton) -photosynthetic pigments: -Structural features: cell wall or not, what it is made of etc. flagella, etc. anything distinguishable in structure. -food storage -reproduction
6. What is meant by alternation of generations?
Sporic lifecycle
algin.
Substance found in brown algae used to thicken foods, forms alginate
Why aren't Cyanobacteria colonies equivalent to a multicellular organism?
The difference between a multicellular organism and a colonial organism is that individual one-celled organisms from a colony can, if separated, survive on their own, while cells from a multicellular life-form
syngamy
The fusion of two gametes in fertilization.
tertiary endosymbiosis
The mechanism by which some eukaryotes acquired the capacity for photosynthesis; for example, a dinoflagellate that apparently lost its chloroplast became photosynthetic by engulfing another protist that had acquired a chloroplast through secondary endosymbiosis.
5. Why are cyanobacteria appropriately classified as bacteria rather than with photosynthetic protists?
The primary difference between them is their cellular organization. Bacteria are single-celled microbes and are prokaryotes, which means they're single-celled organisms lacking specialized organelles. ... In contrast, protists are mostly single-celled eukaryotic organisms that are not plants, fungi, or animals. -only reproduce by fission -prokaryotes don't have flagella
Cryptophyta
a (cryptomonads; crypto = hidden, monad = one cell) Cryptomonads derive their name from their extremely small size and they are most abundant in both marine and freshwaters that are cold or deep. Despite their small size, they are a very important food source for zooplankton. -Autotrophic cryptomonads apparently received their chloroplasts via secondary endosymbiosis of a red algal cell; some of the best evidence for secondary endosymbiosis is found here.(4 membranes found around the chloroplast) -200 species -Pigments Chlorophyll A & C -nucleomorph: red algal cell that has been degenerized -Phycoblins: found in cyano bacteria and red algae, another pigment -high in polyunsaturated fats: people who make oysters feed them cryptophyta
, gametes (egg, sperm),
a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
carrageenan.
a sticky polysaccharide that coats the cell walls of certain species of red algae and that is used in the food industry to control the texture of many food products
Oedogonium,
algae egg container. Is different than plants because it is a single cell.
Sporic life cycle
also known as "alternation of generations", produce two types of multicellular organisms: 1. a haploid gametophyte generation that produces gametes(sperm or eggs) through mitosis 2.a diploid sporophyte generation that produces spores by the process of meiosis
What determines the relative amount of time spent in the haploid or diploid generation during the course of evolution ?
amount of space, or else the haploid and diploid organisms will begin to have to compete.
phycobolin,
any of a group of red or blue photosynthetic pigments present in some algae
7. Use differences in unicellular vs multicellular stages to unambiguously distinguish between zygotic, sporic, and gametic lifecycles.
before
stromatolite
calcium carbonate deposits structures made by cyano bacteria found in fossils (2.7-2.8 billion years ago, some still forming) (calcium carbonate when fossilized is replaced by silica making it stronger)
theca
cellulose wall at top of dinoflagellates (when they divide, each daughter cell gets half a thecka and has to regrow the rest)
plasmodesmata,
channels between adjacent cells, cell to cell connections (also found in plants)
Understand the importance of calcium carbonate deposition by marine algae as a second means of sequestering CO2—why is CO2 removal from the atmosphere important?
cools down the earth.
fission
cyano bacteria divide by fission, one cell dividing into 2 cells. form muselage: gelatinous matirial to retain water.
zygote (auxospore)
diploid cell as the result of syngamy. can either turn into a diploid organism (sporic or gametic) or, through meiosis, forms haploid gametes.
symbiosis
dissimilar organism in close association
cysts
dormant syngamous cells surrounded by protective coverings, waiting for sufficient nutrients.
What evidence exists that suggests most algal lineages are primitively heterotrophic?
endosymbiosis, the membranes around the chloroplasts.
Describe the various forms of Cyanobacteria and identify by name and role any special cell forms.
form branching, filiments, in groups of 4, etc. -colony shape can be a species indicator, -
Where did green algae get their chloroplasts from? What other major algal group are they related to?
from: Archaeplastida, -clade of glaucophytes -red algae
a secondary endosymbiosis of a red algal cell
has nucleomorph: remnants of the red algal cell nucleus
Explain how, over time, a plant with a heteromorphic alternation of generations could evolve into a plant without a gametophytic generation at all.
have the zygote form into an organism instead of just going straight to meiosis? the gameteophytes gradually become gametes.
2. What advantages do colonies have over strictly unicellular organisms?
if you are bigger you can eat bigger organisms. Also if you're big enough some cells can begin to specialize
Draw a Euglena cell with the following parts labeled and their function described: stigma, contractile vacuole, flagella
image
What are the advantages and disadvantages of oogamy compared to isogamy? What features are associated with oogamy (i.e., describe what oogamy is and how it functions).
isogamy: disadvantages: just have to run into each other by chance, nothing propels it to combine. Oogamy: advantages: easier for sperm and egg to meet, because the egg is stationary and the sperm goes to the egg after the chemical signal is released.
Describe the influence/interactions of Cyanobacteria on/with other life-forms (symbiosis) & importance in ecological roles such as global carbon and nitrogen cycles.
lichens, cyanobacterial live in gunnera leaves and roots, cycads have cyano bacteria. nitrogen fixation: cyano bacteria can fix nitrogen, we cannot process elemental nitrogen for our protiens so cyano batceria can fix it in a way to make it usable for other organisms. N2+H=NH3 and ammonia can be taken by plants and used by us. cyano bacteria can fix nitrogen for fertilizer for plants.
What are primary products of the light-dependent and light-independent reactions of photosynthesis? How are these related?
light-dependent rxns(photosynthesis): light energy used to split H2O. e- used to produce ATP and NADPH (electron transport chain changes ADP to ATP). O2 is produced. This occurs in the thylakoid membrane light-independent reactions(darkreactions, calvin cycle): No light required. ATP &NADPH are what drive the conversion of CO2 into carbohydrates [(CH2O)n]. Occurs in the Stroma
Recognize patterns associated with phylogeny such as monophyly, sister groups, plesiomorphy, appomorphy, etc. See the terminology sections from this Wikipedia article for additional help if needed: https://en.wikipedia.org/wiki/Cladistics.
look at sheet
asexual reproduction
mitosis in cells
6CO2 + 6H2O [+ energy] <=> C6H12O6 + 6O2 describes an equilibrium interaction (the number of C, O, and H are equal on both sides of the equation). The left-to-right direction is photosynthesis, and the right-to-left direction is respiration. If the equation is balanced, how does surplus O2 accumulates in the atmosphere?
more o2 is produced than consumed by individuals who mainly use respiration.
Ulothrix
multicellular haploid algae that is fibrous
Why does the formal taxonomic name of the red algae end in "-phyta" while the formal taxonomic name of the brown algae ends in "-phyceae"?
ophyta is for phylym of plant-like things phyceae is for class of algae
6. Discuss how the marine food base can be smaller in biomass than the consumer trophic levels that feed upon it.
phytoplankton(plant-wanderer) as piomonitors phytoplankton is so rapid and quick that they reproduce very quickly (8 divisions in a day so 2^8) which is why it can sustain so many organisms.
4. Explain how and why Cyanobacteria heterocysts affect rice production in Asia
provide rice paddies with nutrients in highly aquatic areas, by forming a symbiotic relationship with little dime-sized ferns (azola) that float in the water, which have a part of their leaf where the cyanobacteria lives. .
coralline algae,
red algae that deposit calcium carbonate within their cell walls, like coral but not coral. some go into 2 diploid and one haploid lifecycle
Dinoflagellates
s (dino = to whirl or rotate) Most dinoflagellates are characterized by 2 flagella that cause the cells to spin, and a conspicuous groove. Many species have cellulose plates called theca that are located inside the Bio 230: Algae (etc) Study Guide 3 cell membrane rather than on the outside like cell walls and plates of other algae. Chloroplasts in dinoflagellates have arisen multiple times by secondary or tertiary endosymbiosis; most autotrophic species have the pigments listed in Table 15.1, but a few obtained their chloroplasts from green algae or other phyla and thus have different pigments. As zooxanthellae, some dinoflagellates are important in coral reef formation. Although several phyla of phytoplankton can produce toxins, dinoflagellates are the most notorious in this ability and Karenia is responsible for the "red tides". Dinoflagellates occur in both marine and fresh waters, and are second only to diatoms as eukaryotic producers at the base of marine food chains. Reproduction can occur by cell division with each daughter cell getting half of the theca and regenerating the other half. Other life cycles are complex and can involve up to at least 24 different stages. -questionable monophyly (gets chloroplasts from different sources) -4000 species -50% without chloroplasts (phagocytes) -50% with chloroplasts have multiple tertiary endosymbiosis (most have Chlorophyll A&C, some have A&B) -
Anisogamy
sexual reproduction by the fusion of dissimilar gametes (egg+sperm)
isogamy,
sexual reproduction by the fusion of similar gametes
oogamy,
sexual reproduction in which one of the gametes (the egg) is large and nonmotile and the other gamete (the sperm) is smaller and motile
What evidence supports the view that green algae gave rise to the land plants?
similar lifecycles, similar pigments, similar startch storage.
frustule;
the silicified cell wall of a diatom, consisting of two valves or overlapping halves. Diatom cell walls consist of two frustules made of silica, one that overlaps the other.
new frustule
the silicified cell wall of a diatom, consisting of two valves or overlapping halves. Diatom cell walls consist of two frustules made of silica, one that overlaps the other. -half from parent, creates half that fits into the other until its the smallest it can be then it forms a gamete
zygotic life cycle
the zygote is the only diploid cell,
Ocean areas differ in their productivity of marine life. Discuss the reasons for the high productivity of continental shelves and areas of cold-water upwelling.
they are higher in nutrients. as it rains runoff bring nutrients to the continental shelves trade winds blow the phytoplankton out where they die(10-30% of nutrients from "raining" dead organisms accumulate on the seafloor) and cold water upwelling brings them back to the continental shelves, as well as under ground for fossil fuels. They also produce DMS(dimethylsulfide) which aids in cloud formation.
Why aren't Cyanobacteria algae?
they are not eukaryotic
akinete
type of Cyanobacteria. resting cells. when conditions get dry these form and when water coes back these will form the colony again.
