Botany Exam 2 Flashcards
(313 cards)
1
Q
What are algae?
A
Photosynthetic Protists
2
Q
How do algae differ from Kingdom Fungi and the fungal-like protists?
A
They are photoautotrophs.
3
Q
How do algae differ from Kingdom Plantae?
A
Their reproductive structures have no protective layer or sterile cells.
4
Q
What is A?
A
Oxygen (O2)
5
Q
What is C?
A
Water (H2O)
6
Q
What is B?
A
Carbon Dioxide (CO2)
7
Q
What is D and what is it producing?
A
Sugars
Starch, Oils, and Cellulose
8
Q
What are the 3 major groups of protists?
A
Algae, Protozoa, and Fungal-like protists
9
Q
What are cyanobacteria?
A
Blue-green “algae”
Not true algae
Have no true nucleus
10
Q
Are all true algae photosynthetic?
A
No. Some are non-photosynthetic.
11
Q
What are protozoa?
A
Heterotrophs
12
Q
What is a heterotroph?
A
An organism that consumes autotrophs for nutrients.
(I.e. Protozoa)
13
Q
What are fungal-like protists?
A
Organisms that resemble fungi in body-form and are heterotrophic via absorptive nutrition.
14
Q
What are phytoplankton?
A
Photosynthetic plankton.
Often found in oceans, lakes, wetlands and rivers.
Occur primarily as single cells, colonies, or short filaments.
15
Q
What does the term “Phyto” mean in Latin?
A
“Plant”
16
Q
What is a plankton?
A
Any minute drifting organism inhabiting the pelagic in marine or freshwater.
17
Q
What does “pelagic” mean?
A
Any region in a body of water that is not close to the bottom or near to the shore.
18
Q
What form is this phytoplankton in and what is the genus?
A
Single cell
Chlamydomonas with flagella
19
Q
What form is this phytoplankton in? What is the genus? What is the structure that is circled?
A
Colonial.
Pediastrum
The structure circled is one cell.
These are mainly found in healthy lakes.
20
Q
What form is this phytoplankton in? What genus is it?
A
Filamentous protist.
Desmidium
21
Q
What does the term “benthic” mean?
A
Bottom
22
Q
What are included in the benthic algae?
A
Cyanobacteria, Unicellular Algae, Macroalgae (freshwater), and Macroalgae (marine).
The marine Macroalgae are seaweeds primarily found on the Pacific coasts because of the cool, nutrient-rich waters.
23
Q
What kind of algae is this and what is the structure (including genus epithet) on it?
A
Benthic unicellular algea.
It is a diatom (Rhoicosphenia curvata).
24
Q
What kind of algae is this? What is the genus epithet?
A
Benthic cyanobacteria
Lyngbya majuscula (marine)
25
What kind of motility are algae classified by?
They swim using eukaryotic flagella:
- Flagellates
- Some flagellated reproductive cells
26
What is the species epithet of this organism? Do all biologists consider this algae?
*Euglena sp.*
No, zoologists consider this an animal.
27
What is this organism?
What is the structure labeled A?
*Euglena sp.*
Flagellum.
28
What is the structure labeled C?
Chloroplast
29
What is the structure labeled D?
Nucleus
30
What is the structure labeled B?
Contractile Vacuole
31
What is the structure labeled F?
Eyespot
32
What are the structures labeled G?
Food reserves (paramylon granules)
33
What is structure A?
Tinsel flagellum
34
What is structure B?
Smooth flagellum
35
What species epithet is this?
How many flagella does it have?
*Ochromonas sp.*
Two visible flagellum
36
What kind of endosymbiosis is this?
Primary endosymbiosis
37
What kind of endosymbiosis is this?
Secondary endosymbiosis
38
What kind of endosymbiosis is this?
Tertiary endosymbiosis
39
What architecture does the chloroplast of Green Algae have?
Thylakoids in stacks of three or more.
40
What achitecture does the chloroplast of Dinoflagellates (in part) and Euglenophytes have?
Thylakoids in stacks of three.
41
What architecture does the chloroplast of Stramenopiles have?
Thylakoids in stacks of three.
42
What architecture does the chloroplast of Red Algae have?
One thylakoids perband with phycobilisomes.
43
Why are algae important?
* Important part of the O2 and carbon cycle
* Food source for many organisms
* They could possibly become a clean fuel source
44
What are in the Phylum Cyanobacteria?
Blue-green "algae" - cyanobacteria
* not as diverse as fungi
* ~ 2,000 species
* mostly freshwater
* named for blue-green or cyan color
45
What are the cell walls of cyanobacteria primarily composed of?
Peptidoglycans
46
Are cyanobacteria motile?
They can be, but they **never** have flagella.
47
What kind of food reserve do cyanobacteria have?
Cyanophyte starch
48
Are cyanobacteria photosynthetic? If so, what pigments do they contain?
Yes, they are.
They have Chlorophyll a, phycobilins, phycocyanin, phycoerythrin (reddish color), and allophycocyanin.
The majority of pigments are **phycocyanin** and **allophycocyanin**.
49
Know what the structure of a cyanobacteria's chloroplast looks like.
50
What genus is this?
Is it unicellular or multicellular?
What form does it grow in?
*Oscillatoria sp.*
Unicellular.
Grows in colonies.
51
What genus is this?
Is this single celled or in a colony?
*Chroococcus spp.*
Single cells.
52
What genus is this?
Is this single celled or in a colony?
*Merismopedia spp.*
Colony.
53
What genus is this?
Single celled or colonized?
*Oscillatoria spp.*
Colony.
54
Genus?
Single celled or colonized?
*Stigonema spp.*
Colony.
55
What genus?
Single celled or colonized?
*Oscillatoria spp.*
Colony.
56
What cyanobacteria is known to grown on asphalt roofs?
*Gloeocapsa magma*
A colonial cyanobacteria
Largely terrestrial
Some symbiotic with fungi, forming lichens
57
What terrestrial cyanobacteria has a species that is edible and often consumed in Asian culture, known as "fat choy" or "black moss"?
*Nostoc flagelliforme*
There are other species of Nostoc that are terrestrial, such as *Nostoc pruniforme* and *Nostoc commune*
58
What cyanobacteria genus is this?
*Nostoc sp.*
59
What cyanobacteria causes Swimmer's Itch?
*Merismopedia sp.*
Can also cause gastrointestinal distress. This is due to the lipopolysaccharides it (like many cyanobacteria) produces.
60
How many planes does *Merismopedia spp. *grow in?
Divides into two planes.
61
What kind of benefits do cyanobacteria bring ecologically?
Form symbiotic relationships with plants and fungi.
Convert atmospheric nitrogen into a rich metabolite that the plant can use.
Some examples of symbiotic relationships with cyanobacteria include:
* Aquatic fern *Azolla*
* Bryophyte - hornwort
* Seed plant - Cycad plant
62
What kind of cyanobacteria are important primary producers and in what setting?
In alkaline waters (not very nutrient-rich), some cyanobacteria such as *Rivularia, Spirulina, *and *Oscillatoria *are primary producers and part of the natural flora.
63
When can cyanobacteria become harmful/a nuisance? In what environment? Give example.
In lakes and ponds a large quantity of certain species (i.e. *Anabaena spp.*) can create toxins and generate a pea soup appearance in the water.
Large blooms can be harmful to people, fish, mollusks, and other animals.
It can cause skin irritation and even liver damage.
There have been instance of cattle dying.
People normally survive but will have flu-like symptoms for 24 hours.
The only way to purify it is to distill it.
64
What happens when there is a large bloom of cyanobacteria containing more **phycoerythrin**?
The water can turn red.
The image below is a satellite image of a lake in Tanzania turned red due to this.
65
How do cyanobacteria resemble other bacteria?
Internally, there is no nucleus, no nuclear membrane, no nucleoli, and no obvious chromosomes.
66
Since there are no flagella, how do cyanobacteria move?
It is believed that, like other **gram negative bacteria**, the outer membrane is important in the process.
67
How can cyanobacteria be motile via **buoyancy**?
**Gas Vesicles:**
* Adjust buoyancy
* Move up or down in water column
* Hollow cylinders; water-tight walls made of protein
* Do not actually contain gas concentrations different from the rest of the cell; the density is lower than the surrounding cytoplasm
68
The photosynthetic apparatus found in cyanobacteria is similar to...
...that found in _some eukaryotic algae_ and is very similar to that of _red algae_.
69
How does cyanobacteria photosynthesis differ from that of other photosynthetic bacteria (i.e. purple sulfur bacteria?
Cyanobacteria produce oxygen, not sulfur or sulfur compounds.
70
What are thylakoids?
Ingrowths of plasma membrane in cyanobacteria (and a membrane-bound compartment inside chloroplasts of eukaryotes) and **is the site of the light-dependent reactions of photosynthesis**.
In some species of cyanobacteria (i.e. Oscillatoria) it makes up to 20% of the dry weight.
71
What are **phycobilisomes**?
Organelles attached to the outer layers of the thylakoids that are concentrated with water soluble pigments [i.e. **Phycobilins**, **Phycocyanin** (blue pigments), **Phycoerythrin** (red pigments), and **Allophycocyanin** (blue pigments)]
Known as the _antenna_ _complex_.
\*Only exception to prokaryotes having no organelles.
72
What important responsibility did cyanobacteria have on Earth for about 2 billion years?
As the only photosynthetic organisms at the time, they raised the level of oxygen in the atmosphere from 1% to 20%.
You can find fozzilized deposits of this in **stromatolites** on Shark Bay, in Australia.
73
What are **stromatolites**?
Domed or layered deposits of calcium carbonate.
Found on Shark Bay, Australia for hundreds of km and can be many meters thick.
They can also be found in Balsan Springs, New York.
74
At what temperature can cyanobacteria continue to grow up to compared to eukaryotes?
They can grow at temperatures as high as _75 degrees Celsius_. Eukaryotes can only function up to about 60 degrees Celsius.
75
What kind of reproduction do cyanobacteria have?
Only **asexual ****reproduction by fragmentation of filaments of cells and simple prokaryotic binary fission **is known. Sexual reproduction is _unkown_ as are mitosis and meiosis.
76
Describe the process of asexual reproduction in cyanobacteria:
1. Fission - prokaryotic DNA replicates
2. Each daughter strand of the chromosome separates
3. DNA becomes isolated in opposite poles of the cell
4. The cell finishes division by pinching off the central part of the cell, forming new transverse walls
77
Although sexual reproduction is unknown, what else can happen besides asexual reproduction?
_Genetic recombination by transformation_ (acquiring pieces of DNA from donor cells) and possibly by _conjugation_ (formation of a narrow tube between two cells through which DNA is passed).
78
What are **hormogonia**?
Multicellular fragments from broken cyanobacteria filaments
79
What are **heterocysts**?
The source of nitrogen fixation in cyanobacteria.
They are also the most important source of fixed nitrogen in rice paddies.
80
What are **akinetes**?
Large, rounded, thick-walled, spore-like cells containing food reserves (_cyanophyte starch)_ in cyanobacteria.
They *develop* when the cyanobacteria is under stress *to survive harsh conditions*.
They can germinate into metabolically active cells under favorable conditions.
81
What is a **mucilaginous sheath**?
It is a "protective layer" that acts as a buffer to the external environment.
82
What is a **trichome**?
A chain of vegetative cells in cyanobacteria often surrounded by a _mucilaginous sheath_.
Also can be considered single cells aggregated together in a colony.
83
What is structure **A**?
What is structure **B**?
**A**: mucilaginous sheath
**B**: hormogonium
84
What is structure **C**?
What is structure **D**?
**C**: heterocyst
**D**: akinete
85
What is structure **E**?
What is structure **F**?
**E**: mucilaginous sheath
**F**: heterocyst
86
What is structure **G**?
What is structure **H**?
**G**: akinete
**H**: heterocyst
87
What are in Supergroup Excavata?
Eukaryotes
88
Where did the Supergroup Excavata get its name?
For the **suspension-feeding groove of excavated type** that is presumed to be secondarily lost in many taxa within this group.
Food particles are taken into cells by phagotrophy of feeding groove region.
89
Do all of the members of Supergroup Excavata feed by phagotrophy in the excavated groove?
No. Phagotrophy was secondarily lost in the _photosynthetic Euglenoids_ and _some of the non-photosynthetic Euglenoids_ (the groups that secondarily lost a plastid).
90
What is the feeding-groove in Supergroup Excavata composed of?
Rods of microtubules and non-microtubules fibers.
91
What is primary endosymbiosis?
The process in which a eukaryote engulfs another living prokaryote.
If a eukaryotic cell engulfs a photosynthetic alga cell, the larger organism can then use the products of the alga and become an autotrophic organism.
92
What is secondary endosymbiosis?
When a eukaryote cell engulfs another eukaryote cell that has undergone primary endosymbiosis.
The main difference between *primary* and *secondary* endosymbiosis that after the cell is engulfed it becomes dependent on the larger cell. It cannot leave and return to its original state.
93
What Supergroup does Phylum Euglenophyta belong to?
Supergroup Excavata
94
How many species are in Phylum Euglenophyta?
About 900.
~ _Two-thirds_ of the genera are *heterotrophic*.
The remaining _1/3_ of the genera in this group *contain chloroplasts*.
95
What is the food reserve for members of Phylum Euglenophyta?
**Paramylon**.
It is stored in little "tic-tac" or "Pez candy" shaped structures.
96
What pigments are in members of Phylum Euglenophyta?
Chlorophyll a, Chlorophyll b, and carotenoids.
Evidence suggests that chloroplasts were drived from secondary endosymbiosis of a green algae.
97
Do members of Phylum Euglenophyta have flagella?
Yes. They have apical flagella (two variable in form).
98
Do members of Phylum Euglenophyta have a cell wall?
No. They have a proteinaceous **pellicle** - a pellicle with helical protein strips.
99
What is a pellicle?
Found in _Euglenophyta_; a series of strip-like plates underneath the cell membrane arranged in a spiral; pellicle may be rigid or plates may be able to slide as the cell expands and contracts during movement.
100
Are Euglenophyta uni- or multi- cellular?
Unicellular.
101
What kind of environment do you find members of Euglenophyta in?
Freshwater.
They are important primary producers in the world's "freshwater" systems.
102
How do members of Euglenophyta feed?
In some groups they engulf food by phagocytosis (such as bacteria do).
Some are osmotrophic - the uptake of dissolved organic compounds by osmosis for nutrition.
Some are photosynthetic.
Some photosynthetic species function as heterotrophs in the dark (i.e. they are **mixotrophic**).
103
What does the term "mixotrophic" mean?
An organism that goes back and forth between feeding by photosynthesis and osmosis.
104
How can some groups in Euglenophyta sense light?
They have a complex called an **eyespot**.
The eyespot is composed of a paraflagellar body (Fla) and the eyespot (Sti). These two work together to sense light.
105
How do phagotrophic euglenoids phagocytise [feed on] bacteria?
They contain a series of rods and veins that are used to phagocytise the bacteria.
Ex: *Petalomonas minuta*
Ex: *Entosiphon ovatus*
106
What kinds of apical flagella are found on Euglenophyta?
In one group, both flagella are emergent (as seen in *Eutreptia viridis* and *Entosiphon ovatus*).
In most groups, one flagellum is emergent and one is non-emergent (as seen in *Euglena gracillis* and *Pentalomonas minuta*).
107
What type of cristae do Euglenozoa have?
**Disk-shaped mitochondrial cristae.**
108
How do **Euglenoids** move?
**Euglenoids** have unique interlocking protein strips beneath the plasma membrane.
This allows them to crawl through mud - it is called _euglenoid movement_ OR also, _metaboly_.
109
How are members of Euglenophyta classified?
Classification is traditionally based on:
* Flagella morphology
* Presence of light sensing complex (eyespot)
* Mechanism of feeding
* Autotrophic OR
* Heterotrophic OR
* Osmotrophy
* Phagotrophy
* Mixotrophic
110
What group of algae are most pollution tolerant?
Some species of *Euglena*.
In a copper mine outside of Butte, Montana there is a pit that has over time filled with water with a pH of 2.0 and contains heavy metals.
*Euglena mutabilis* can be found inhabiting this extreme environment. Theoretically, it could exist in out stomachs, since it can survive at that pH level.
111
What is a commercial use for *Euglena*?
It can be used in the _commercial production of Vitamin B12_, which is used in the manufacture of red blood cells, cell growth, and cell maintenance.
Vitamin B12 cannot be made by any plants or animals. A select species of bacteria contain the enzymes necessary to generate it.
112
How do *Euglena* gain motility?
It results from a large flagellum which extends from the **Reservoir** (*aka the gullet/ampulla*) which contains a second, short flagellum. All are located at the _anterior region_ of the cell.
Euglenids lack a firm cell wall. Instead, they are bounded by a flexible **Pellicle** with a thin _mucilaginous coating_.
113
What is the **Reservoir** of *Euglena*?
The Reservoir is a narrow-necked, flask-shaped cavity at the anterior end of a Euglena cell, which has one of two apical flagella extending from it.
114
Identify the structures.
**A**: Emergent flagellum
**B**: Paramylon body
**C**: Posterior region
**D**: Anterior region
**E**: Eyespot
**F**: Contractile Vacuole
**G**: Nucleus
115
What is **euglenoid movement**?
Because the cell is sprially twisted, the *Euglena* rotate through the environment. Deformation followed by spiral movement of the pellicle causes the cells to radically alter shape - that is **euglenoid movement**.
116
How do *Euglena* reproduce?
Asexual reproduction by **closed mitosis** - nuclear division with the nuclear membrane remaining intact.
The nucleolus is persistent.
The nucleus elongates becoming dumbbell shaped and is then pinched off in the middle.
Prior to cell division a second set of flagella develop and the cell cleaves longitudinally beginning at the apical end.
_There has never been sexual reproduction seen in this group._
117
What characteristics are representative of Supergroup Chromalveolata?
* The plastid was derived by secondary endosymbiosis of an archaeplastid ancestor.
* The plastid was secondarily lost or reduced in some with tertiary reacquisition of a chloroplast in specific groups.
* All photosynthetic members possess chlorophyll c.
118
What is an archaeplastid?
The group we refer to as plants.
119
What other name do we have for Phylum Dinophyta?
Phylum Pyrrophyta
Common name is Dinoflagellates.
120
What supergroup is Dinophyta included in?
Supergroup Chromalveolata
121
How many species are included in P. Dinophyta?
Between 2,000 and 4,000.
122
About half of the genera in Dinophyta are what?
Heterotrophs
123
What are some of the phototrophic species in Dinophyta considered?
Mixotrophs
124
What pigments are found in phototrophic species of Dinophyta?
Chlorophyll a & c; carotenoids mainly peridin and several xanthophylls.
125
What is the food reserve in species of Dinophyta?
Starch
126
Do all Dinoflagellates have a cell wall?
Some species have a *theca *present, which is composed of cullulose and pectin.
Some, however, lack a cell wall - making them bioluminescent (=athecate?).
127
In what environment are Dinoflagellates found in?
They are primarily marine.
128
Do species in Dinophyta have flagella?
Most groups are flagellated (specifically 2 tinsel flagella).
* One flagellum is in the cinculum.
* Another flagellum is in the sulcus.
129
What is a cingulum?
What is a sulcus?
A **cingulum **is the groove that laterally wraps around the body of a Dinoflagellate where one of the two tinsel flagella are located and is used to rotate the body.
A **sulcus** is a groove that is longitudinal down the body of a Dinoflagellate and has a flagellum within it that is used to propel the body.
130
Are Dinoflagellates uni- or multicellular?
*Mostly unicelluar *with a few genera growing as filaments.
131
In what form are the chromosomes in Dinophyta?
They remain permanently condensed and tightly wound around organelles.
132
How did the chloroplast in species of Dinophyta originate?
Via secondary and tertiary endosymbiosis (3 membranes).
The engulfment of an algae whose lineage acquired its plastid primarily (e.g. red algae) or through secondary emdosymbiosis (e.g. Diatom).
133
Are members of Dinophyta free living or symbionts?
Most are free living (e.g. phytoplankton).
* Phytoplankton are photosynthetic algae living on top of water - they are one of the most important primary producers (next to diatoms).
Some are endosymbionts in coral, sea anemones, etc. (zooxanthellae).
* In corals they can provide up to 90$% of a coral's energy requirements.
134
What are some examples of bioluminescent species in Dinophyta?
*Xenia* in soft coral **(1)**
Zooxanthellae in *Xenia* **(2)**
135
# Fill in the blanks.
The dinoflagellates are grouped within the **(1)** algae [the algae of **(2)**] based in part on molecular data and that most photosynthetic members have chlorophylls a, c and xanthophylls.
1 = **chromophyte**
2 = **chromalveolata**
136
# Fill in the blanks.
The chromophyte algae encompass the **(1)**[**(2)**] lineage. Some of these **(3)** groups include:
* golden algae (Chrysophyceae)
* yellow-green algae (Xanthophyceae=Tribophyceae)
* brown algae (Phaeophyceae)
* Diatoms (Bacillariophyceae)
The **(4)** or **(5)** possess secondary plastids and have two dissimilar flagella (whiplash and tinsel).
1 = **stramenopiles**
2 = **heterokonts**
3 = **stramenopile algae**
4 = **stramenopiles**
5 = **heterokonts**
137
# Fill in the blanks.
Based in part on molecular, ultra-structural data, and the acquisition of their chloroplast (via endosymbiosis) we know that the **(1)** form a separate lineage from the **(2)**, and belong within the **(3)**.
1 = **Dinophyta**
2 = **stramenopiles**
3 = **Alveolates**
138
# Fill in the blanks.
Some species have a cell wall referred to as a **(1)**. **(2)** are usually divided into two armored lobes separated by a central, equatorial slightly spural groove called the **(3) **{=**(4)**}. The vertical groove is called the **(5)**.
1 = **theca**
2 = **Thecal plates**
3 = **Cingulum**
4 = **Girdle**
5 = **Sulcus**
* The flagellum associated with the cingulum encircles the cell (rotates cell).
* The flagellum that which is associated with the sulcus trails behind (propels the cell).
139
Identify the structures:
A = epitheca
B = cingulum
C = sulcus
D = plates
E = flagella
F = sutures
G = hypotheca
140
Define the term **athecate**.
When some species lack a theca (cell wall), they are considered **athecate**. Some of these species are bioluminescent. This is not fully understood in dinoflagelates as it involves the substrate luciferin and the enzyme luciferase.
141
What is bioluminescence?
The production of light by a chemical reaction in organisms. It occurs in about 90% of the organisms that live in the ocean.
142
What are some of the features and hypotheses of bioluminescent dinoflagellates?
There is a hypothesis that dinoflagellate bioluminescence is protection against predators. It is believed to disrupt the feeding predators by startling them.
Three stimuli have been observed to cause bioluminescence in dinoflagellates: *mechanical, chemical, and temperature stimulation*.
143
Why is bioluminescence blue?
_Transmission:_
Blue-green light (wavelength ca. 470 nm) transmits father in water than most other wavelengths of "perceivable" light.
_Most marine organisms can see blue light:_
Some organisms lack the ability to perceive longer wavelengths (yellow and red) while others cannot perceive shorter wavelengths (violet and ultraviolet).
144
How do dinoflagellates reproduce?
Sexual reproduction rarely occurs. The zygote forms a cyst (resting stage) which undergoes meiosis to yield more typical cells.
*Reproduction is typically asexual* and a consequence of the cell splitting into two halves essentially along the cingulum and then regenerating the other half.
145
Explain sexual reproduction in dinoflagellates:
Two dinoflagellates will join together (called fusion). This stage is the planozygote stage. Then they change, stometimes quite dramatically, in shape and size. They get much bigger and they harden their shell. This stage is called hypnozygote. Then when the weather warms up, the cyst breaks out of its shell (excystment). This stage quickly becomes a normal dinoflagellate again.
146
Fill in the blanks for the life cycle of a dinoflagellate:
A = 2n
B = Vegetative Cell
C = Asexual Phase
D = Sexual Phase
E = Meiosis
F = 4
147
Fill in the blanks for the life cycle of a dinoflagellate:
A = 2n
B = gametes
C = ecdysal cyst [short-term]
D = (hynozygote) resting cyst [long-term]
E = planozigote
F = n
148
Explain the dinoflagellates' relevance as primary producers in the oceans.
They are second to the diatoms relative to their importance as primary producers in the oceans.
Under favorable conditions, they may divide several times a day. As such, they are widely recognized to produce 'blooms' or 'red tides' in which cells can reach concentrations of 1-20 million per liter (normally 1-20 thousand per liter).
In large blooms some dinoflagellates species can be toxic. Nearly 20% of all dinoflagellate species produce one or more toxic compounds.
* Example: *Gymnodinium* bloom in Florida
149
Explain how a toxic algal bloom occurs.
1. Resting cysts lay dormant on the ocean floor, buried in sediment. If undisturbed by physical or natural forces, they can stay in this state for years. If oxygen is present, germination may proceed if conditions are right.
2. The cysts can germinate only during certain times of the year with warer temperatures and increased sunlight stimulating germination. The cysts breaks open, and a swimming cell emerges. The cell reproduces by a simple division within a few days of "hatching".
3. If conditions remain optimal, cells will continue to divide, reproducing exponentially, 2 to 4 to 8. A single cell could produce several hundred cells within a couple of weeks. If other single cells reproduce similarly, then toxicity in shellfish may occur.
4. When nutrients are gone, growth stops and gametes are formed. Two gametes join to form one cell, which develops into a zygote and then into a cyst.
5. The cyst falls to the bottom of the ocean and is capable of germination the following year.
150
Give some examples of toxic algal blooms.
* LaJolla California red tide (1)
* *Noctiluca* bloom - California (2)
* North Carolina *Gymnodinium breve* bloom (3)
* The sea surface temperature; blue = 8 degrees Celsius; red = 32 degrees C
151
What are the main Harmful Algal Blooms (HABs) aka Red Tides?
Is there any way to eliminate the toxins caused by these algal blooms?
* **Saxitoxin** (*Alexandrium*) - Paralytic Shellfish Poisoning (_PSP_); severe disruption of neurological (neurotoxin) processes, among other symptoms
* **Brevetoxin** (*Gymnodinium*) - Neurotoxic Shellfish Poisoning (_NSP_); 'milder' disruption of neurological processes, gastroenteritis, and respiratory irritation
* **Ciguatoxin** (*Gambierdiscus*) - Ciguatera Fish Poisoning (_CFP_) (eating fish contaminated with ciguatoxin); gastrointestinal, cardiovascular, and neurological symptoms
* **Okadaic Acid** (*Dinophysis*) - Diarrhetic Shellfish Poisoning (_DSP_); diarrhea, not a neurotoxin, no fatalities
Cooking and freezing does _nothing_ to deactivate the respective toxins!
152
# Fill in blank.
Paralytic shellfish poisioning (PSP) as a consequence of the neurotoxin **(1)** (10,000 times more toxic than cocaine).
What else can be said of PSP?
1 = **saxitoxin**
Shellfish bioaccumulate the toxin and when these are eaten by humans respiratory and cardiovascular arrest occur in about 12 hours.
Toxicity in the bivalves (clams, mussels, oysters, snails, scallops) disappears within 2-3 (6) weeks (though can last for two years in butter clams) after the bloom, but may persist for months.
153
What is *Pfiesteria*?
A toxic predatory dinoflagellate that (in tides) is in some cases responsible for fish kills.
In other cases the fish kills are in response to changes in dissolved O2 and etc. due to the large blooms of dinoflagellates.
154
Identify the structures labeled A through D.
A = Nontoxic zoospore
B = Large Rough Cyst
C = Toxic Zoospore
D = Filliose "star" amoeba
155
What are Zooxanthellae?
A group of endosymbiontic dinoflagellates that form a mutualistic symbiosis with coral reefs, among other groups [such as protozoa, clams, flatworms, jellyfish, sea anemones, etc.], to help them thrive in waters that are nutrient poor (oligotrophic).
The coral polyps catch little food for themselves, most of their nutrition is derived from their endosymbiont, which releases up to 60% of its photosynthates to its host.
*Symbiodinium* is a common Zooxanthellae.
156
When were the Heterkonts derived and by whom?
What is another name used for Heterokontophyta?
What does the name "Heterokont" mean?
Derived by van den Hoek in 1978.
They are also known as the Stramenopiles.
"Hetero" = Differing ; "kont" = types of flagella
157
What are the classes in the phylum Heterokontophyta?
What is another class evolutionarily related to the Heterokontophyta that is also a stramenopile?
Class Bascillariophyceae = diatoms
Class Chrysophyceae = golden algae
Class Phaeophyceae = brown algae
* Brown algae are considered their own phylum in some places online.
Class Xanthophyceae = yellow-green algae
Class Oomycota is closely related to those in Heterokontophyta, but mostly lost its chloroplast somewhere in its evolutionary time period.
158
# Fill in the blanks.
In P. Heterokontophyta, the body of an organism has two flagella. One whiplash and one tinsel type.
* Tinsel (stiff hairs called **(1)** of which there are two rows. They are composed of **(2)** and synthesized in the cisternae of the endoplasmic reticulum).
1 = **tripartite mastiogonemes**
2 = **glycoprotein**
159
What is the general internal structure of a member of Heterokontophyta?
The chloroplast is enclosed by two membranes of the endoplasmic reticulum. In addition the chloroplast lies up against the nucleus.
Thylakoids in stalks of three usually run around the enture periphery of the chloroplast.
The food reserve polysaccharide chrysolaminarin ("starch") is formed in vacuoules outside the chloroplast.
An eyespot and flagellar swelling together form a photoreceptor apparatus.
Golgi bodies lie appressed to the nucleus.
160
What are the chloroplast pigments in Heterokontophyta?
Chlorophyll a, c1 and c2 (algae); _chlorophyll b is never present_.
Fucoxanthin is the primary accessory pigment (except in xanthophytes, which contain vaucheriaxanthin).
161
What are the Class Bascillariophyceae?
A class within P. Heterokontophyta, they are *diatoms*.
There are approximately 10,000 species, but the group is 10x more diverse than that.
There are both marine and freshwater groups.
They are the most abundant group of algae in marine phytoplankton, contributing to large oil deposits.
162
What is the cell wall composed of in diatoms?
What pigments do they contain?
How was their chloroplast obtained?
The cell wall is composed of silica and is termed a _frustule_.
Chlorophyll a & c and carotenoids (mainly fucoxanthin) are the pigments they contain.
The chloroplast was derived by secondary endosymbiosis by a red algal unicell.
**Ths group is highly divergent but they all look very similar.**
163
What is the food reserve in diatoms?
Are diatoms flagellated?
Are diatoms of any commercial use to us?
Do they produce any toxins?
The food reserve in diatoms is chrysolaminarin.
Only males gametes are flagellated in *centric forms* with one apical tinsel flagellum.
They do have some commercial applications (insect killer, filter powder).
Some species do produce toxins (*Pseudo-nitzschia*).
164
What are the orders in Bacillariophyceae?
**Order Pennales** - bilaterally symmetrical pennate diatoms; found in both fresh and marine waters.
**Order Centrales** - Radially symmetrical centric diatoms; found mainly in marine waters but some rare members can be found in freshwater.
165
# Fill in the blanks.
The tiny **(1)** (silicon dioxide) body within which the cell exists is called a **(2)**.
Each frustule consists of two **(3)** the upper and lower surface:
* The larger (upper) is the **(4)**
* The smaller (lower) is the **(5)**
The region in which the two valves overlap are referred to as the **(6)**.
1 = **Silica**
2 = **frustule**
3 = **valves**
4 = **epitheca**
5 = **hypotheca**
6 = **girdle**
166
# Fill in the blanks.
The frustule is finely sculptured with **(1)** (pores) that are aligned in **(2)** (linear arrangement).
Most pennate diatoms have a central, longitudinal groove in the wall of one valve called the **(3)** (secretes mucilage allowing the diatom to move across a substrate or to adhere to it).
1 = **Punctae**
2 = **Striae**
3 = **Raphe**
167
How do diatoms reproduce?
Usually asexually.
1. Mitosis followed by cytokinesis.
2. Each of the original valves become the outer half of the new frustule.
3. Each daughter cell must secrete one new valve, which is usually the smaller (inner) one.
4. Each successive generation produced from the hypotheca is progessively smaller (*shrinking diatom syndrome*).
5. The mechanism they use to escape the shrinking size is sexual reproduction!
168
Describe sexual reproduction in diatoms.
Diatoms are typically diploid.
1. Meiosis yields cells that function as gametes (isogamous in the pennate and oogamous in the centric).
2. Fusion of gametes and formation of the zygote results in the reconstitution of a normal-sized cell.
3. Only the small cells resulting from repeated mitotic divisions are capable of sexual reproduction.
4. Only one or two gametes are formed from each meiotic division.
169
Label the chart of sexual reproduction in centric diatoms.
A = **Sperm (n)**
B = **Egg nucleus (n)**
C = **Aurospore makes new frustules (2n)**
D = **Frustule halves**
170
What are some commercial applications for diatoms?
**Diatomaceous earth** in the past has been used as dynamite, a filtering agent, abrasive (metal polish, facial scrub), insecticide (functions to dehydrate specific insects by puncturing holes in the exoskeleton), and an insulant (e.g. bricks and fire proofing material).
**Live diatoms** today can be used as biodiesel. Oil and natural gas formed from marine plankton. In some oil deposits the oil was formed predominantly from the remains of diatoms.
171
Explain the diatom fossil record.
The diatom fossil record extends back to the Jurassic, 150 million years ago (MYA) with the centric morphotype.
The pennate did not appear until the Tertiary, approximately 65 MYA.
Thus, the pennate diatoms are presumed to have originated from the centric diatoms.
172
173
What phylum does the class Chrysophyceae belong to ?
Phylum Heterokontophyta
174
About how many species are in the class Chrysophyceae?
Approximately 1,000 species.
175
What is the common name for members of class Chrysophyceae?
Golden Algae
176
What is the food reserve in golden algae?
The food reserve is Chrysolaminarin.
177
What are the photosynthetic pigments in golden algae?
Chlorophyll a & c; carotenoids mainly fucoxanthin.
178
Are the golden algae fresh- or marine water?
Uni- or multicellular?
Predominantly fresh water but there are a few marine groups.
They are all unicellular.
179
Do the members of golden algae have a cell wall?
A cell wall is absent in some; Cell wall silica scales (kind of "covering" the cell).
Some groups also contain cellulose in scales.
180
Do members of the golden algae have flagella?
They have two flagella - one whiplash and one tinsel type (heterokont).
Golden algae are flagellated, unicellular and colonial algae.
181
How do the golden algae reproduce?
Sexual reproduction has been observed in *only a few genera* and is _typically isogamous_.
182
How did the chloroplast in golden algae evolve?
Secondary endosymbiosis.
183
Define the term **Synura**.
A motile, spherical colony that produces fishy smelling ketones and aldehydes that can add an unpleasant odor to drinking water - cells have silica scales, one or two large peripheral chloroplasts.
Aldehydes and ketones are organic compounds which incorporate a carbonyl
functional group, C=O.
184
# Fill in the blanks.
**(1)** is an extremely common loricate chrysophyte; each cell lives inside a cellulosic vase shaped chamber [**(2)**].
1 = **Dinobryon**
2 = **Lorica**
A dominant phytoplankton of small lakes that forms siliceous ornamented cysts to permit overwintering.
185
What are the Xanthophyceae?
A class within Phylum Heterokontophyta, also known as the "yellow-green algae" for their yellow-green coloring.
186
About how many species are in the yellow-green algae?
Approximately 600 species.
187
Are the yellow-green algae freshwater, marine water, or a mixture of both?
They are mostly freshwater.
188
What are the photosynthetic pigments in yellow-green algae?
Chlorophyll a & c (c in low quantities); carotenoids with **_no_** fucoxanthin (*has vaucheriaxanthin*).
189
What is the food reserve in yellow-green algae?
Chrysolaminarin
190
Do the yellow-green algae have cell walls?
Yes. The cell walls are made of cellulose (with silica sometimes present).
191
Do members of the yellow-green algae have flagella?
Yes, they have two. One whiplash and one tinsel type (heterokont).
192
What is the common name for members in Class Phaeophyceae?
The brown algae
193
What Phylum and Supergroup does the Class Phaeophyceae belong to?
Phylum Heterokontophyta; Supergroup Chomalveolata
194
Are the brown algae marine or freshwater?
Mostly marine with some fresh water groups.
195
Do members of the brown algae have a cell wall?
Yes, made primarily of cellulose, with pectin and alginic acid.
196
What are the photosynthetic pigments in the brown algae?
Chlorophyll a & c; carotenoids, mainly fucoxanthin (gives the brown algae its characteristic color)
197
How did the brown algae acquire its plastid?
The chloroplast was derived by secondary endosymbiosis.
198
Do members of the brown algae have flagella?
Yes, but only in gametes of most groups. They are heterokonts (one tinsel and one whiplash).
199
What is the food reserve in members of the brown algae?
Laminarin
200
What is the most notable group in the brown algae?
Order Laminariales (the kelps)
201
Why are the brown algae ecologically important?
They form communities for other organisms.
202
In members of Order Ectocarpales, how are the thalli structured?
The thalli are uniseriate filaments of two types:
1. Creeping with apical growth
2. Erect with intercalary growth
203
What life cycle do members of Order Ectocarpales have?
What are the specialized structures?
Life cycle is sporic meiosis (alternation of generations).
The specialized structures are:
* Plurilocular mitosporangia
* Plurilocular gametangia
* Unilocular meiosporangia
204
What are the gametes considered in the Order Ectocarpales?
The gametes are anisogamous (they look similar in this group but they behave differently).
205
What group is considered to be the most primitive group of the C. Phaeophyceae?
Order Ectocarpales
206
# Fill in the blanks.
In O. Ectocarpales, the diploid zygotes germinate and develop into adult **(1)**.
The adult sporothallus can reproduce **(2)** forming **(3)** (multichambered) mitosporangia.
The plurilocular sporangia produce **(4)** diploid zoospores which upon **(5)** produce a new diploid sporothallus.
1 = **sporophyte**
2 = **asexually**
3 = **Plurilocular**
4 = **bi-flagellated**
5 = **germination**
207
# Fill in the blanks.
In the Order Ectocarpales:
On a sporothallus a **(1)** sporangium (meiosporangium) is the structure in which meiosis will occur.
Haploid bi-flagellates **(2)** are produced. These haploid zoospores will develop into a haploid **(3)**.
The **(4)** will produce plurilocular gametangia similar to the plurilocular mitosporangia.
Biflagellate isogametes **(5)** to form the diploid zygote.
When the zygote germinates the life cycle starts anew.
1 = **Unilocular**
2 = **meiospores**
3 = **gametothallus**
4 = **gametophyte**
5 = **fuse**
208
Fill in the labeled structures.
A = Sporophyte
B = Unilocular sporangium
C = syngamy
D = Plurilocular sporangium
209
Fill in the labeled structures:
A = **Unilocular sporangium**
B = **Plurilocular gametangium or sporangium**
210
What is the shape of the thallus in members of O. Dictyotales?
The thalli are strap or fan-shaped.
211
What is the growth form in O. Dictyotales?
Apical growth
212
What does _parenchymatous_ mean?
What groups are labeled as such?
_Parenchymatous_ means that it is a macroscopic algae with tissue of undifferentiated cells and growth from a meristem with cell division in 3 dimensions.
O. Dictyotales, O. Laminariales, O. Fucales (I.e. **all of Phylum Phaeophyceae** ***except* O. Ectocarpales**)
213
Are there any calcified members in O. Dictyotales?
What does it mean to be calcified?
There is one calcified genus in Dictyotales: *Padina*
Calcified algae are a unique subset of marine seaweeds that incorporate calcium carbonate—essentially, limestone— into their thalli.
214
Describe the life cycle of O. Dictyotales.
The life cycle is sporic meiosis (alternation of generations).
The gametes are oogamous.
The male gamete has a single anterior tinsel flagellum (whiplash flagellum probably secondarily lost).
The gametes form in groups (**sori**) on the thallus.
215
What is the main characteristic of members in O. Laminariales?
They are large algal blades usually found in cold, nutrient rich waters.
The gametophyte fail to produce gametes in waters warmer than 10-15 degrees Celsius, thus ensuring their distribution solely in cold waters.
216
Are members of O. Laminariales parenchymatous?
Yes
They are macroscopic algae with tissues of undifferentiated cells and growth from a meristem with cell division in 3 dimensions.
217
What is the growth form in members of O. Laminariales?
Growth is from an intercalary meristem between the stipe and blade.
218
Describe the life cycle of Laminariales.
The life cycle is sporic meiosis (heteromorphic alternation of generations).
Has macrothallus (sporophyte; dominant) & microthallus (gametophyte; ephemeral [=lasting for a very short time]).
The gametes are oogamous.
219
# Fill in the blanks.
The sporothallus is fastened to the substrate of the subtidal zone by a **(1)**.
The sporothallus is generally divided into one of more **(2)** [=**(3)**] which are primarily photosynthetic organs. These are connected to the **(1)** by a **(4)**.
1 = holdfast
2 = lamina
3 = blades
4 = stipe
220
What is the region surrounded by the blue box?
What is its purpose?
Is there another region on the algae that is similar to this?
It is a primary meristematic zone.
This meristem allows for the replacement of old winter-damaged blades during the spring months and add to the length of the stipe as well.
A superficial meristematic layer also occurs on the lamina.
221
What are the lobe-like projections on the stipe of this *Alaria* species (circled in black)?
What is their function?
The lobe-like projects are sporophylls.
Sporophyll are a specialized "leaf" bearing one or more sporangia.
222
What is unique about this *Agarum fimbriatum* (Sea Colander)?
There are perforations on the blade.
223
What is the genus and species of this algae? Common name?
*Postelsia palmaeformis*
Sea Palm
224
What are the (physically) largest algal genera?
Where do they occur?
How large can they be?
The giant kelps *Macrocystis* and *Nereocystis* are, physically, the largest.
They occur on the west coast of North America.
They form extensive forests with some sporothalli reaching 50-70 meters long.
225
Why is Order Laminariales an economically important group?
**Alginic acid** is harvested from these algae and used in various ways. Alginate generally acts as emulsifier (ingredient used to bind together normally non-combinative) in paints, varnish, toothpaste, and shaving cream.
* Ammonium alginate: fireproofing
* Calcium alginate: plastics and laundry starches
* Sodium alginate: stabilizer of ice-cream
226
What are some examples of the use of O. Laminariales in food and beverages?
* Wakame (*Alaria* sp.)
* Kombu (*Laminaria japonica*)
* Seaweed ale
227
What is the growth form in O. Fucales?
Apical growth
228
Are the members of O. Fucales parenchymatous?
Yes
229
Descrive the life cycle of O. Fucales.
The life cycle is gametic meiosis.
The gametes are oogamous.
The gametes are born in conceptacles.
230
What are the structures circled in black on this member of Fucales?
What is the scientific name of this?
Branches can contain inflated tips called _receptacles_. These aid in buoyancy.
Frequently conceptacles are limited to this region.
*Ascophyllum nodosum*
231
Where are the gametes formed in *Fucus*?
How many eggs and sperm per each gametangium?
The gametes are formed in chambers called _conceptacles_ on swollen, terminal portions of the thallus called _receptacles_.
Only **8 eggs** per female gametangium and **64 sperm** in male gametangium.
The conceptacles also contain paraphyses (sterile cells). \*Remember, these were also found in members of Ascomycota.\*
232
What is special about the genus *Sargassum* in O. Fucales?
Members of this genus can live as free floating thalli, which accumulate in the mid Atlantic Ocean in such large number that the area if known as the Sargasso Sea. On the west coast there are a lot of *Sargassum* that are _benthic_.
This is unlike the rest of the brown algae which dominate in the harsh environment of the intertidal zone.
In pelagic (free-floating) species of *Sargassum* there has been a loss of sexual reproduction. Unlike the benthic species, pelagic species only reproduce vegetatively (only asexual). This means _there are no conceptacles_ on the pelagic members of this genus.
233
What is something interesting about *Sargassum* and its relation to marine animals?
Marine animals mimic the appearance of the algae as camouflage.
234
What does the Supergroup Archaeplastida include?
Red algae, Green algae, and everything else we will learn this semester.
235
What are the characteristics of Archaeplastida?
* A photosynthetic plastid with chlorophyll a from an ancestral primary endosymbiotic event with a cyanobacterium.
* Plastid secondarily lost or reduced in some.
* Usually with cellulose cell wall.
* Mitochondria with flat cristae.
* Starch as the photosynthetic storage product.
236
What are the photosynthetic pigments associated with members of P. Rhodophyta?
Chlorophyll a, (d in some groups - lower red algae), phycobilins: phycocyanin, **phycoerythrin **(majority of pigment - red color), & allophycocyanin [arranged in phycobilisomes (also in cyanobacteria)].
237
Do members of Rhodophyta have flagella?
No, flagellated stages are absent.
238
What is the cell wall composed of in members of Rhodophyta?
Cell wall is composed of cellulose, sulfated polysachharides & some of the calcified groups contain calcium carbonate.
239
What is sexual reproduction like in Rhodophyta?
Sexual reproduction is _oogamous_.
240
Are the thylakoids stacked in Rhodophyta?
No, they are non-aggregated.
241
Why is Rhodophyta an economically and ecologically important group?
In the medical and industrial field specific classes of sulfated polysaccharides in the cell wall are extracted for various uses. These extracted and refined compounds are known as _agar and carageenans_.
Nori and Dulse are eaten as food worldwide.
242
What are the **chlorophylls**?
What are **accessory pigments**?
What are they?
**Chlorophylls **- known as the green pigments as they reflect green light
**Accessory pigments** - Pigments that cannot directly transfer sunlight to the photosynthetic pathway, but _must pass their absorbed energy to chlorophyll_, as pasrt of the light dependent reactions.
* **Carotenoids** - known as the yellow to red pigments as they reflect yellow to red light
* These pigments are broken down into two classes:
* Xanthophylls (which contain oxygen)
* Carotens (which are purely hydrocarbons, and _contain no oxygen)_
* **Phycobilins **- water soluble pigments
* Phycocyanin blue pigments (teal)
* Phycoerythrin red pigments
243
WWhat are the main characteristics of Class Bangiophyceae?
* Considered the "lower red algae" - their rankless name is _Bangiophytes_
* The group is paraphyletic
* They are mostly unicellular
* Most are freshwater species; they make up about 1% of the diversity in the Rhodophyta
244
What are the main characteristics in the Class Floridiophyceae?
* They are known as the "higher red algae" - their rankless name is Floridiophytes
* This group is monophyletic
* Most are marine species; they make up for about 99% of the diversity in the Rhodophyta
* Has a single common ancestor with the Bangiophytes
245
How many chloroplast do members of the bangiophytes have?
One single stellate (star shaped) chloroplast per cell
246
What is the growth form in the bangiophytes?
Growth is intercalary
247
What are pit connections?
They are the result of incomplete cytokinesis.
Found in floridiophytes.
248
Are there any pit connections present in bangiophytes?
Generally, no
249
What is reproduction in bangiophytes?
Sexual reproduction, generally
250
How many nuclei are in cells of bangiophytes?
All cells are uninucleate.
251
Are bangiophytes unicelluar or multicellular?
There is a presence of *both* unicellular and multicellular species.
252
What is *Porphyra umbilicalis *commonly known as?
What is special about it?
It is commonly known as **Nori**.
The conchelis (diploid) stage of Nori on shells is grown in tanks in seeding centers where light and temperature are controlled to generate conchosporangium formation.
The result is eaten worldwide, specifically Japan and Wales (called **laver** there), as a common component in main dishes and as snacks.
The Japanese thought that the founder's, Dr. Kathleen Drew, discovery was so great that they constructed a stature in Japan to honor her achievement.
The Japanese alsp celebrate her achievement "The Drew Festival" every year on April 14.
253
How many nuclei do floridiophytes have?
The cells are usually multinucleate in vegetative cells, except for meristematic cells.
254
How many chloroplast do members of floridiophytes have?
They have many discoid chloroplasts.
255
What is the growth form in floridiophytes?
Apical growth.
256
Are pit connections (plugs) found in floridiophytes?
Pit plugs are common features shared between cells.
257
Are floridiophytes unicellular or multicellular?
Species are multicellular
258
What is reproduction in floridiophytes?
Sexual reproduction is widespread.
259
# Fill in the blanks descriving the reproductive structures in floridiophytes.
The male gametophyte produce gametangia called **(1)**, each of which forms a non-flagellated gamete, the **(2)**.
The **(2)** drift passively on currents until it encounters a female gamete in a single-celled gametangium, an oogonium. The oogonium is specifically called a **(3)** which has a long, thread-like projection called a **(4)**.
1 = **Spermatangium**
2 = **Spermatium** (pl. **Spermatia**)
3 = **Carpogonium**
4 = **Trichogyne**
260
# Fill in the blanks describing reproductive structures in floridiophytes.
The zygote develops into the first diploid phase, the **(1)** which is a simple, branching, filamentous diploid thallus attached to the female gametophyte. In some casses it is surrounded by a protective layer of gametophyte tissue called **(2)**. The **(1)** and **(2)** (or surrounding envelope of the gametophyte) are collectively called the **(3)**.
1 = **Carposporophyte**
2 = **Pericarp**
3 = **Cystocarp**
261
# Fill in the blanks describing the reproductive structures of floridiophytes.
The carposporophyte produces diploid mitospores called **(1)**. **(1)** germinate and through growth and differentiation form a free licing sporophyte called the **(2)**. Within the **(2)** meiosis will occur in a meiosporangium called a **(3)** which produces haploid **(4)**.
**(4)** will germinate into a new gametophyte.
1 = **Carpospores**
2 = **Tetrasporophyte**
3 = **Tetrasporangium**
4 = **Tetraspores**
262
What is an important group in the Class Floridiophyceae?
An important group is the **Order Corallinales**.
263
What are the characteristics of O. Corallinales?
* This group contains calcified red algae
* These algae are reef builders by generation of hard banks in sandy substratums
* These red algae are responsible for a calcium carbonate deposit almost 1500 m thick in the Marshall Islands
* They are capable of growing to a depth of over 200 m in clear water
264
What is the name for detached corraline algae?
What and where is it used?
**Maërl** is the name for detached corraline algae.
It is sold in the United Kingdom as a top dressing for soils. Over 500,000 tons of this material is collected from specific regions of Europe. Much of it is harvested from Brittany, France.
It is also used in:
* Waste water treatment plants
* Bedding materials for penned animals
265
What is/are the red algal order(s) whose species are utilized as sources for agar?
**Order Gelidales** & **Order Gracilariales**
266
What order has the species commonly known as Irish Moss?
What is the scientific name for Irish Moss?
What is Irish Moss used for and where is it found?
**Order Gigartinales**
*Chondrus crispus*
Irish Moss is common on the Atlantic coast and is harvested in bulk from the intertidal zone in eastern Canada and western Europe for the extraction of carrageenin, a _commercially used gelling agent_ - used to stabilize or thicken chocolate milk, cheese, ice cream, and jellied foods.
267
What order has the species commonly known as Dulse?
What is the scientific name?
What is the use?
**Order Palmariales**
*Palmaria palmata*
Dulse is harvested and eaten in the British Isles and globally. It is a good source of potassium, vitamins, iron, fluoride, iodine, and trace elements.
It is served as a cocktail snack. Inferior dulse, usually due to poor drying, is broken into flakes or ground into powder for use as a seasoning.
268
Is P. Chlorophyta a poly-, para-, or monophyletic group.
A paraphyletic group.
269
What are the pigments found in Chlorophyta?
Chlorophyll a & b, and carotenoids.
270
What is the food reserve in Chlorophyta?
Amylose starch (in many).
271
What is the cell wall composed of in Chlorophyta?
Cell wall is composed of cellulose, pectins; some of the calcified groups contain calcium carbonate.
272
What are the forms (i.e. unicellular, colonial, etc.) within Chlorophyta?
In habit there are unicellular, colonial, filamentous siphonous (large multinucleate cells), and parenchymatous forms.
273
What is unique about the phylum Chlorophyta in regards to land plants?
A lineage within this phylum gave rise to the land plants.
274
What are in the Class Micromonadophyceae?
Primitive green flagellates that are usually covered with acidic polysaccharide scales.
The cells can have 1-8 flagella.
This class does not contain well defined cytological and morphological features.
Many of the organisms in this group are referred to as the **Prasinophytes**.
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What are the main characteristics of Class Chlorophyceae?
* Most are freshwater species
* Cellulose terminal complex (snth. complx.) linear row
* Position of flagella in cells anterior; symmetrical root system
* Mitotic spindle breaks down during telophase
* Mitosis closed
* Cell division by furrowing and phycoplast
* In some groups with cell plate and plasmodemata
* Eyespots common
* Theca covering motile cells
* Meiosis ccues when zygote germinates (_zygotic meiosis_)
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What are in Order Volvocales?
Motile vegetative unicells or colonies.
Haploid cells reproduce asexually by mitosis and sexually by either isogamy, anisogamy, or oogamy, depending on the species.
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# Fill in the blanks regarding forms of Volvocales.
Colonial forms are **(1)** (an algal colony with a fixed number of cells arranged in a constant way).
1 = **Coenobium**
278
Describe the life cycle of *Volvox*.
The life cycle of *Volvox* includes asexual formation of daughter colonies inside the parent colony.
Sexual reproduction is oogamous.
The zygote is a resting phase that undergoes meiosis.
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What are in the Order Chlorococcales?
Non-flagellated vegetative unicells or colonies.
* *Chlorella* is unicelluar
* *Scenedesmus* is usually four cells in a row
* *Pediastrum* is cells in a round plate
* *Hydrodictyon* is a net of cells
A number of genera are common freshwater taxa.
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Do members of C. Ulvophyceae have eyespots?
Yes, eyespots are common.
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Is C. Ulvophyceae marine or freshwater?
Predominantly marine
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Is mitosis open or closed in C. Ulvophyceae?
It is closed mitosis.
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What is the life cycle in C. Ulvophyceae?
The life cycle is either sporic or zygotic meiosis.
284
Describe Class Ulvophyceae
* Predominantly marine
* Cellulose terminal complex (synth. complx.) linear row
* Position of flagella in cells anterior; symmetrical root system
* Spindle apparatus persistent during telophase
* Mitosis closed
* Cell division by cleavage furrow
* Absence of plasmodesmata and cell plate
* Scales covering motile cells
* Eyespots common
* Some groups calciified; some groups are siphonous
* Life cycle sporic or zygotic meiosis
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What is in the Order Ulvales?
This order includes species with laminar (sheet-like) thalli that are generally two cells thick except for species of *Ulvaria* that are only one cell layer thick.
286
Describe the life cycle of Ulvales.
The life cycle is isomorphic alternation of generations.
Gamete producing gametangia are produced on gametophytes.
Isogametes are released and fuse to form a diploid zygote which grows into a lettuce-leaf-like sporophyte.
Meiosporangia produce meiospores which develop into indistinguishable lettuce-leaf-like gametophytes.
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What is in Order Cladophorales?
Includes species with uniseriate, siphonous, unbranched or branched, multinucleate thalli. *Cladophora*, a common genus, grows in temperate and tropical marine and freshwater habitats. Some species are free floating masses in stagnant, eutrophic ponds, others are attached to stones or even animals.
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Descrive the life cycle of *Cladophora*.
*Cladophora* has alternation of isomorphic generations.
Quadriflagellate zoospores (meiospores) form in ordinary vegetative cells of the sporophyte. The haploid zoospores settle on the substrate and germinate into dioecious gametophytes. The gametophytes form biflagellate isogamous gametes. Gametes fuse externally forming quadriflagellate zygotes which settle and germinate into a new sporophyte.
The haploid zoospores break through the sides of the cells and enter the water there is no specific aperture.
The haploid gametes will burst from lateral apertures in branches of gametangia.
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What is in Order Dasycladales?
The Order includes mostly marine tropical siphonous algae - each mature thallus is a single, giant uninucleate cell with a huge central vacuole; the initial diploid nucleus (which undergoes meiosis) is located in the basal rhizoidal portion of the cell.
Fossil record goes back more than 400 million years.
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Describe *Acetabularia* and its life cycle.
Acetabularia - the distinctive umbrella-shaped cap is a whorl of many large gametangia which produce many cysts.
The cysts are dispersed into the open water and release many biflagellate isogametes, which fuse to form a zygote.
This develops into another vegetative cell.
Thus thallus is functionally a single giant cell.
The life cycle is zygotic meiosis.
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What is in O. Caulerpales?
The Order includes green algae with siphonous thalli (coenocytic) which are often large and complex. The group is predominantly tropical. Variability is common, even within genera!
The genus *Caulerpa* usually has a creeping rhizome-like (fleshy, elongate, non-erect stem, often but not always subterranean) portion with rhizoids anchoring the sporophyte (a single, giant, multinucleate cell) to the sandy substrate). The erect portion can look like feathers or ferns or bunches of grapes, or even the branchlets of a cypress tree.
292
Describe reproduction and the structures in C. Caulerpales: *Codium*
Anisogamous gametes are produces in distinctive clud-shaped gametangia called **Utricles** that are separated from the rest of the coenocytic thallus by septa.
The zygote is formed by anisogamy and either undergoes meiosis or develops into a small, siphonous sporophyte with a single large diploid nucleus which undergoes meiosis.
Mitosis and continued differentiation gives rise to the gametophyte.
Sexual reproduction in this group is only understood in a few cases.
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What genus species is known as the "killer algae"?
Why is it called this?
*Caulerpa taxifolia* is known as the killer algae.
It is an invasive species of green algae (protist) that out competes native marine flora. This species was introduced to a non-native habitat (the Mediterranean Sea), most likely, by the dumping of the contents of an aquarium into the sea.
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Do members of C. Charophyceae have eyespots?
No, eyespots are absent.
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It mitosis open or closed in C. Charophyceae?
Mitosis is open.
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Is C. Charophyceae freshwater, marine, or both?
It is predominantly freshwater.
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How does cell division occur in C. Charophyceae?
Cell division occurs by means of a furrowing and phragmoplast.
298
When does meiosis occur in Charophyceae?
What life cycle (meiosis) is it?
Meiosis occurs when the zygote germinates.
It is zygotic meiosis.
299
What are some characteristics of Charophyceae?
* Predominantly freshwater
* Cellulose terminal complex (synth. complx.) rossette
* Position of flagella in cells anterior; assymmetrical root system
* Spindle apparatus present during cytokinesis
* Mitosis is open
* Cell division occurs by means of a furrowing and phragmoplast
* Plasmodesmata and cell plate in some groups
* Eyespots absent
* Scales covering motile cells
* Meiosis occurs when zygote germinates (zygotic meiosis)
300
In the Charophyceae, what Order and Family has filamentous thalli?
**Order Zygnematales: Family Zygnemataceae**
A freshwater group
No flagellated cells
Reproduction by conjugation
301
Describe reproduction by conjugation in Zygnemataceae.
**Compatible cells align, form a connection, and undergo syngamy.**
Some species can move by a gliding motion
Filaments are hapoid and each cell uninucleate
Conjugation:
* Conjugation papillae
* Conjugation papillae dissolve common wall forming conjugation tube
* "Male" gamete moves by ameoboid movement toward the "female" gamete
The syngamy occurs and a thick-walled zygote forms which functions as a resting spore.
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What is fragmentation considered in algae?
Asexual reproduction
303
What is conjugation considered in algae?
Sexual reproduction
304
What is the difference between *Spirogyra* conjugation and *Zygnema* conjugation?
In *Spirogyra* the zygote is formed in one of the filaments but in *Zygnema* the zygote forms between the conjugating strands.
305
In Charophyceae, what Order and Family has unicellular thalli?
Order Zygnematales: Family Desmidaceae
306
What group of algae is commonly referred to as the Desmids?
**Order Zygnematales: Family Desmidaceae**
The conjugating cells in these algae form a large zygote.
307
Describe asexual reproduction in Desmids
After a cell divides each small half will grow and differentiate becoming just like that of the larger half.
308
What are some characteristics for Order Coleochaetales?
* Most cells bear setae (hairs)
* Protective cells surround zygote
* Possible ancestral group to land plants
309
# Fill in the blanks for important information on the genus *Coleochaete.*
The genus *Coleochaete* generates a phragmoplast, has plasmodesmata and the spore wall contain sporopollenin like that found in members of the **(1)**.
Also the zygote is permanently retained on the haploid thallus and is surrounded by **(2)** produced by the haploid thallus.
The zygote forms a resting spore and then undergoes **(3)** as in other algae, creating 16-32 meiospores.
Hypothetically, mutations resulting in mitotic divisions of the diploid phase and a delay in **(3)** would yield a sporophyte dependent on the **(4)**, as is the case in liverworts, hornworts, and mosses of the **(1)**.
1 = **land plants**
2 = **protective cells**
3 = **meiosis**
4 = **gametophyte**
310
What group of algae is known as the "Stoneworts"?
Order Charales
Protective cells surround zygote
Possible ancestral group to land plants
311
What are the most common genera in Order Charales?
*Chara* and *Nitella*
312
# Fill in the blanks explaining the structure of members in Charales, specifically being *Chara*.
The **(1)** thalli are haploid and composed of well defined nodal and internodal regions. Nodes bear whorls of lateral branches. Young cells are uninucleate but become multinucleate when older.
Thalli are erect and produce gametangia at the nodes. The **(2)** [**(3)**] is a small thin-walled sphere with many antheridial (speratogenous) filaments inside. Each cell of the filament produces one biflagellate, spiral sperm cell.
The **(4)** [**(5)**] a jacket which is always composed of five, long, spirally arranged cells an egg. Following fertilization the zygote forms a thick wall becoming an Oospore, then the oopsore is released and settles on the substratum.
Meiosis occurs just prior to **(6)** - Meiosis occurs, three-nucleate degenerate, the remaining uni-nucleate haploid cell gives rise to new haploid thallus.
1 = **filamentous**
2 = **globule**
3 = **male**
4 = **nucule**
5 = **female**
6 = **oospore germination**
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