Algae Flashcards
1
Q
What is the loose definition of plants?
A
Organisms that perform oxygenic photosynthesis.
2
Q
What is the strict definition of plants?
A
Organisms belonging to the Kingdom Plantae
3
Q
What did Thomas Malthus contribute to the theory of evolution?
A
Population growth is geometric, which means the arithmetic growth of resources cannot sustain all individuals.
4
Q
What is macroevolution?
A
Investigation of large-scale trends and major events in the history of life.
ex. endosymbiosis
5
Q
What is microevolution?
A
Investigation of selective pressures within a particular species over a short period of time, resulting in speciation.
ex. natural selection, mutation, gene flow, genetic drift, non-random mating
6
Q
What is allopatric speciation?
A
Takes place when a physical barrier subdivides a population of a small part of a population is separated from the main population.
ie. geographical isolation
7
Q
What is sympatric speciation?
A
Occurs within one continuously distributed population when reproductive isolation evolves between distinct subgroups.
ie. reproductive isolation (can be caused by polyploidy)
8
Q
What is parapatric speciation?
A
Occurs when different environmental conditions or ecological niches cause speciation within a geographically continuous population.
ie. ecological isolation
9
Q
What causes polyploidy?
A
Plants can combine their own gametes after nondisjunction during self-fertilization.
ie. instant speciation
10
Q
What are the benefits of polyploidy?
A
- Hybrid vigour/heterosis and seedlessness due to additional growth expression and sterility.
- Resistant to recessive mutations.
- Trend towards heterozygosity over time.
- Quicker adaptation potential due to increased opportunities for mutation.
11
Q
What are the drawbacks of polyploidy?
A
- Issues with mitosis or meiosis due to misalignment.
- Takes up space, requiring larger structures (ex. stomates).
12
Q
What is systematics?
A
Study of the diversification of organisms and the relationships among living organisms through time.
13
Q
What is Linnaeus’ binomial nomenclature system based on?
A
Shared traits.
14
Q
What are phylogenies?
A
Branching diagrams that show the relationships between species according to the recency of their common ancestors.
ie. NOT hierarchical
15
Q
What is a taxon?
A
Any taxonomic group at any level of interest/investigation. Terminal taxa are at the ends of branches on phylogenies.
16
Q
What is a clade?
A
All descendants of a common ancestor, ie. every branch evolved from a single node, monophyletic group.
17
Q
What is a polyphyletic group?
A
Group that doesn’t include one common ancestor for all lineages.
ie. NOT a clade
18
Q
What is a paraphyletic group?
A
Group that includes a common ancestor and only some lineages descended from it.
ie. NOT a clade
19
Q
What is a cladogram?
A
Graphical representation of splitting events.
20
Q
What types of shared characters are used in phylogenies?
A
- Morphological (ex. seed shapes).
- Chromosomal (ex. ploidy).
- Molecular (ex. chloroplast DNA sequences).
21
Q
What is the principle of parsimony?
A
Phylogenies requiring the fewest evolutionary changes is the best estimate of history, due to the evolution of new traits being rare (ie. most mutations are deleterious). Therefore, if ancestor and modern species both possess a character, assume that all intermediates also possessed this character.
ie. Occam’s razor
22
Q
What role did cyanobacteria play in geologic history?
A
Thrived during the anoxic Archaean period, then experienced a precipitous decline during the Great Oxidation Event.
23
Q
What species of Bacteria are capable of photosynthesis?
A
Synechococcus and Gloebacter are cyanobacteria.
Acidobacteria, Rhodocyclus, Chlorobium, Heliobacterium, and Chloroflexus gained photosynthetic capacity through transformation.
24
Q
What is transformation?
A
Method of horizontal gene transfer wherein pieces of bacterial DNA are taken up by other bacteria, leading to increasing complexity and diversity over time.
25
What are the different body types found in cyanobacteria?
1. Unicellular (binary fission, no sexual stage).
2. Colonies (undifferentiated vegetative cells surrounded by mucilaginous sheath).
3. Filaments/trichomes (microplasmodesmata, hormogonium, asexual).
4. Chains (heterocytes, akinetes).
5. Branched filaments (programmed cell death, heterocytes).
26
What is a mucilagenous sheath?
Outer coating of long, unbranched polysaccharides (glycoaminoglycans).
27
What are the benefits of mucilagenous sheaths?
1. Prevents desiccation and retains water.
2. Buoyancy.
3. Cell adhesion (ie. colony formation).
4. Deters herbivores.
5. UV protection.
28
In what ways do cyanobacteria exhibit multicellularity?
1. Cell adhesion.
2. Division of labour (ie. specialized cells).
3. Clonal multiplication.
4. Communication and signalling (primitive plasmodesmata).
5. Genetic and developmental regulation.
29
What is a hormogonium?
Small fragment of a filament separated by a separation disc (from programmed cell death) used for asexual reproduction.
30
What are akinetes?
Asexual cells in cyanobacteria formed in response to unfavourable conditions, accumulating storage materials and suspending metabolism. Will break open and begin new individual when good conditions return.
31
What are heterocytes?
Thick-walled cells in filamentous cyanobacteria that reduce oxygen diffusion and participate in nitrogen fixation.
32
In what extreme environments have algae been found?
1. Thermophilic algae in hot springs (results in coloured layers under the water surface).
2. Algae that can tolerate very high salinity in salt deposits.
33
What are stromatolites?
Layered carbonate fossils formed from repeated algal biofilms. They are found globally because algae are so ubiquitous.
34
What is primary endosymbiosis?
Ingestion of cyanobacterial cells into eukaryotic host cells, where they became endosymbionts.
35
What evidence supports endosymbiosis?
1. Maintain own DNA.
2. Divide by binary fission.
3. Cell wall remnants.
4. Same size.
5. Phagocytosis observed in algae.
36
What is metaboly?
Biological process describing the ability of some cells to change their shape, typically to acquire prey.
ie. found in heterotrophic euglenoids
37
What is a pellicle?
Hinged "armour" under euglenoid membranes, made of proteins called articulins, used to control hydrostatic pressure for movement.
ie. less pellicle strips in heterotrophs allows more movement, more pellicle strips in phototrophs restrains movement
38
What is an eyespot?
Accumulation of pigments that allows some algae to orient themselves in the water column and protect from light damage.
ie. common euglenoid feature
39
What is a paramylon?
Storage carbon retained in the cytoplasm of euglenoids.
ie. glucan linkages in β1-3 configuration
40
What is a lorica?
Hard outer covering that absorbs minerals and protects from herbivory. Develops from the mucilagenous sheath and restrains movement and division.
ie. common feature in euglenoids
41
What are the characteristics of euglenoids?
Unicellular, aquatic, auto- or heterotrophic, divide by longitudinal binary fission.
42
What is the general morphology of dinoflagellates?
Heavily armoured (unless they are unarmoured), two flagella, epithica, and hypothica.
43
What is the difference between the two flagella in dinoflagellates?
Longitudinal extends from the sulcus and is used for speed and distance movement.
Transverse coils around the transverse groove and is used for rotation and fear.
44
How do dinoflagellates feed?
Can be phototrophic, heterotrophic, or mixotrophic. Heterotrophic dinoflagellates utilize phagocytosis, peduncles, and feeding veils.
45
What is a peduncle?
Flexible extension of cytoplasm used for capturing nutrients.
ie. heterotrophic dinoflagellate feeding mechanism
46
What is a pallium?
Feeding veil extended beyond the cell wall that captures organisms.
ie. heterotrophic dinoflagellate feeding mechanism
47
What is peridinin?
Common accessory pigment in photosynthetic dinoflagellates.
48
What are trichocysts?
Protein organelles located under the cell surface and ejected in response to stimuli for defense and propulsion.
ie. dinoflagellate and some ciliate defense mechanism
49
How does bioluminescence occur in dinoflagellates?
Thin structures called scintillons emit light according to a circadian rhythm that upregulates luciferase production at night in order to improve feeding ability and protect from herbivores.
50
What are red tides?
Discoloration of seawater caused by a bloom of toxic (ex. brevitoxin, saxitoxin) dinoflagellates taking up carbon. Cyclical, but made worse by eutrophication.
51
What types of symbiotic relationships do dinoflagellates form?
Coral
52
What are stramenophiles?
Diverse group of organisms with pili that arose from secondary symbiosis of red algae and are closely related to oomycetes. Contain pigments: chlorophyll a and c, fucoxanthin (for UV protection).
53
What groups are included in the stramenopiles?
Diatoms (Bacillariophyceae), brown algae (Phaeophyceans), and golden algae.
54
What is the morphology of diatoms?
Epitheca and hypotheca. Centric, pennate, etc.
55
What type of sexual life cycle do diatoms have?
Gametic. Involves auxospores.
56
What are the components of brown algae cell walls?
1. Cellulose.
2. Alginic acid (prevents desiccation).
3. Fucans (strengthens cell walls).
57
What pigments are found in brown algae?
1. Chlorophyll a and c.
2. Fucoxanthin.
3. β-carotene.
58
How does evolution affect alternation of generations?
Higher complexity typically shows a more dominant diploid stage.
ex. spruce trees mostly diploid, mosses mostly haploid
59
What are spores?
Haploid cells capable of mitotic division. Produce gametophytes.
60
What are gametes?
Haploid cells capable of development only by fusion with another gamete. Produce sporophytes.
61
What are sporophytes?
Multicellular diploid bodies. Produce spores by meiosis.
62
What are gametophytes?
Multicellular haploid bodies. Produce gametes by mitosis.
63
What is chrysolaminarian?
Photosynthetic reserve material found in brown algae.
64
What is the sexual life cycle of brown algae?
Sporic most commonly (can be isomorphic or heteromorphic) but sometimes gametic (Ex. Fucus).
65
What is the difference between isomorphic and heteromorphic sexual life cycles?
Isomorphic means the haploid and diploid stages are morphologically similar.
Heteromorphic means the gametophyte and sporophyte are morphologically different.
66
What are common morphological structures in brown algae?
Holdfasts, pneumatocysts.
67
What do the terms monoecious and dioecious refer to?
Refer to distribution of reproductive structures on gametic brown algae. Monoecious means conceptacles are on the same individual thallus. Dioecious means there are male and female bodies.
68
What are coralline algae?
Deposit calcium carbonate in their cell walls to help obtain carbon dioxide. Grow in deep seabeds with very little light.
69
What pigments are present in red algae and why are they necessary?
1. Chlorophyll a.
2. Phycocyanin.
3. Phycoerythrin.
4. Carotenoids.
In order to absorb as much light as possible because 98% of red algae live in deep marine habitats.
70
What is the importance of red algae?
Crustose coralline algae stabilize coral reefs. Derivatives found to inhibit tumour growth and have antiviral activity. Source of carageenan.
71
What are pit plugs?
Specialized structures in the pores between adjacent cells used for transport, maintaining cellular integrity.
ie. defining feature of red algae
72
How do multinucleate red algae relate to siphonous red algae?
Siphonous red algae are typically multinucleate and have a specific long structure.
73
What type of phylogeny are green algae?
Paraphyletic (Chlorophyta).
74
What does the UTC clade represent?
Core Chlorophyta, most close algal lineage to Streptophyta.
75
What are the cell wall components of green algae?
1. Cellulose.
2. Hemicellulose.
3. Pectin.
76
What component makes up diatom cell walls and why?
Silica for strength, rigidity, buoyancy, and light penetration.
77
What types of plastids are commonly found in green algae?
Cup, napkin, plate, asteroidal, reticulate.
78
What are the characteristic features of green algae?
Stacked thylakoid membranes, 2 membranes around chloroplasts, pyrenoid, storage of starch in stroma of chloroplasts.
79
What pigments are found in green algae?
1. Chlorophyll a.
2. Chlorophyll b (unique to green algae and plants).
3. Carotenoids.
80
What is the purpose of the pyrenoid?
Increases carbon dioxide concentration, increases ability of cell to fix carbon.
81
What are the main lineages of the UTC clade?
1. Ulvophyceae (sporic, isomorphic).
2. Trebuouxiophyceae (lichen symbionts, unicells or colonies).
3. Chlorophyceae (most diverse, includes Volvox, Chlamydemonas).
82
What differentiates Coleochaetophyceae and Charophyceae?
Coleochaetes form flat discs and Charales form branching, plant-like bodies.
83
What are the main similarities between streptophytes and land plants?
1. Oogamous.
2. Mitosis involving phragmoplast.
3. Cell connectivity by plasmodesmata.
4. Apical growth (in some).
84
How does apical growth occur in Charales?
Cell division is concentrated in the top apex to increase control and lower risk of mutations.
85
What lineage do stoneworts belong to?
Charaphyceae.
86
What type of life cycle do Charales have and how is this related to land plants?
Zygotic, believed that the multicellular embryo in land plants was caused by a mutation delaying meiosis (undergoing mitosis instead) in an ancestor similar to Charales.
87
Why are plants referred to as embryophytes?
Exhibit retention of the zygote and nutritional dependence of the sporophyte. The embryo develops within female tissue which provides nutrition and desiccation prevention.
88
What are the four main tenets of evolution?
1. Variation occurs randomly.
2. Traits can be inherited.
3. Environments have limited resources.
4. Favourable traits survive.
89
What is the general definition of algae?
Photosynthetic, oxygen-producing aquatic bacteria or protists that lack the terrestrial adaptations found in land plants.
90
What are coenobia?
Colonies with a genetically defined number and pattern of cells.
91
What is the difference between periphyton and phytoplankton?
Branched filamentous algae attached to rocks or substrates are periphyton, free-floating algae in the water column are phytoplankton.
92
What are the body types of macroalgae?
1. Coenocytic (large multinucleate, no cell walls).
2. Parenchymatous (tissues with plasmodesmata).
3. Pseudoparenchymatous (look like tissue, fundamentally filamentous).
93
What is anisogamous reproduction?
Differentiated male and female motile gametes.
94
What is zygotic meiosis?
Only diploid cells are zygotes, while gametes and non-reproductive bodies are haploid. Meiosis segregates mating-type genes in order to produce two varieties of mating cells.
95
What is gametic meiosis?
Haploid gametes are produced from diploid vegetative cells. The fusion of gametes creates a diploid zygote that undergoes repeated mitotic divisions to form a multicellular diploid body.
96
What is sporic meiosis?
Haploid spores grow into multicellular haploid bodies called gametophytes, which produce haploid gametes, gametes fuse to form diploid zygotes that undergo mitotic divisions to form multicellular diploid bodies called sporophytes (which produce haploid spores).
97
What is the SAR supergroup?
Stramenopiles, Alveolata, Rhizaria.
98
What differentiates red algae from other eukaryotes?
Lack flagella, perform special alternation of generations cycle instead.
99
What is the T in the TSAR supergroup?
Plastid-less protists called telonemids.
100
What is transduction?
Incorporation of cyanobacterial genes into viruses for later transfer into other cyanobacteria.
101
What are three methods for gene transfer in eukaryotic algae?
1. Viral transduction.
2. Phagotrophy.
3. Endosymbiotic gene transfer.
102
What changes occur when akinetes are upregulated?
1. Decreased gas vesicles.
2. Increased size.
3. Thicker walls.
4. Storage deposition.
103
What characterizes thermophilic cyanobacteria?
Thick, colourful banded mats, encasement of amorphous silica.
104
What are the three general features of protists?
1. Not plants, fungi, or animals.
2. Often microscopic in size.
3. Occur mostly in moist or aquatic habitats.
105
Why are most microscopic protists aquatic?
High SA:V ratio that makes them susceptible to desiccation but able to obtain dissolved nutrients.
106
What is the major factor in the small size of protists?
Maintaining effective flagellar movement.
107
What are ciliates?
More powerful, slightly larger heterotrophic protists descended from a single ancestor.
108
What are Excavata?
Unicellular flagellated protists with divets for feeding.
ie. contains euglenoids, Discoba
109
What are Alveolata?
Unicellular alveoli-containing protists, ciliates, dinoflagellates, and apicomplexans.
110
What are the four methods of protist nutrient acquisition?
1. Phagotrophy (engulfing particulate matter).
2. Osmotrophy (uptake of minerals).
3. Autotrophy (photosynthesis).
4. Mixotrophy (photosynthesis and heterotrophy).
111
What are carpogonia?
Haploid female gametes retained on the female gametophyte.
112
What are spermatia?
Haploid male gametes dispersed from the male gametophyte.
113
What is a carposporophyte?
Diploid female body that develops from the zygote attached to the female gametophyte.
114
What are carpospores?
Diploid spores dispersed from the carposporophyte.
115
What is a tetrasporophyte?
Independent diploid bodies that release tetraspores.
116
What are tetraspores?
Haploid spores dispersed from tetrasporophytes that develop into gametophytes.
