Test Exam I.5 Diatoms
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Why it has its color?
may be unicellular (majority) or colonial, or loosely aggregated into irregulat filaments
all adults non-motile; some sperm motile (1 flagellum)
Predominance of carotenoids, especially fucoxanthin giving the cells a golden-brown color
diploid so they have a haplobiontic diploid type of life cycle
on the basis of symmetry, cells have two basic shapes (or variations of these shapes): pennate (bilateral symmetry) and centric (radial symmetry; circular, triangular, square)
Cell wall composed of __, like a __, made of __. Walls have extensive delicate mrkings, such as __(3)__ that are used to identify species. 2 valves= __
- two overlapping halves (valves)
- silica (glas)
- one frustule
- usually by cell division (mitosis)
- each daughter cell receives one valve from the parent cell and has to make a second valve; parent valve always forms the top valve
Alot are __ or __.
__: dots= holes in the cell wall.
How may different shapes?
Used to test?
in fresh/marine water and at the base of the food chains
- many different shapes
Advantage of having a cells that make cell wall out of silica?
Things will get stuck to silica like what?
- hard to break down
- energy inexpensive-->not as much energy
- required--> more energy for reproduction
nutrients; giving cells advantage in absorbing nutrients
gametes have flagella (reproductive)
a few look like pennate
What kind of chlorophylls do diatoms have?
chlorophylls a and c
Pennate diatoms fit together like __.
The cell wall is made of __.
a petri dish
Mitosis is triggered by __. The parent cell does what?
a need for reproduction
separates and becomes the top part for each daughter cell
Only __ have flagella. Population of cells that aren't __.
Throughout reproduction, what happens regardign size?
The most common way they reproduce is by __.
haploid cells (gametes); motile
the average size keeps getting smaller, eventually triggering a need for reproduction (sexual)
The result of asex reproduction by cell division in the diatoms, by which what?
one of the two daughter cells is ordinarily slightly smaller than the parent cell
Diatoms are source of some __. Up to __ of a diatoms mass is __. If diatoms are eaten by ish, what happens?
Diatoms also contribute to __.
- fish liver oils
- forty percent
- their oils may be storedin the livers of the fish (ex: cod liver oil)
It is possible that vast deposits of diatoms in the past produced some of the __ we're using now.
A few species cause __.
- Occurrence: First reported outbreak was in __, __, __ from eating locally cultured blue mussels; 4 dead adn 153 reported symptoms.
- amnesic shellfish poisoning
- Prince Edward Island, Canada
What are shellfish? What happens when they eat the diatoms?
it gets stuck in the gills; possible wound forms infection
Amnesic shelfish poisoning has occurred from Alaska to southern California and in New England. May and June, 1998: death fo > __ from eating anchoivies that had fed on __.
__ are responsible: Species of the genera __ and __.
- 400 sea lions
Toxin: A heat-stable neurotoxin called __; there is __.
domoic acid; antidote
Source for humans that may cause amnesic shellfish poisoning
seafood, like mussels, clams, crabs and anchovies that feed on diatoms; the toxin does not harm them
Within 24 hours: nausea, vomiting, diarrhe, abdominal cramps
Neorological symptoms that appear over 48 hours: headache, dizziness, confusion, difficulty breathing, loss of short-term memory, seizures, disorientation, dementia, coma
What can result?
__ has caused problems in the __ of salmon and cod on the west coast. The cells have long hollow spines that break off and penetrate fish gills, doing what?
Damage may lead to __.
- disrupting gas exchange and causing bleeding
- secondary bacterial infections
What does diatomaceous earth consists of?
diatoms shels (glass cell walls) remaining after the protoplasm dies; deposits have built up over millions of years
Deposits of marine origin (shallow seas): where?
Lompac, CA--largest deposit in the world; bed > 650' feet
Santa Maria oil fields
Deposits of freshwater origins
Smaller in size than marine deposits; United Kingdom, Maryland, Nevada, Washington, Oregon
Uses of diatomaceous earth relate to four of its characteristics:
1) exceptionally high melting point (1750 degree Celsius)
2) insolubility in most acids and other liquids (i.e. inert)
3) high porosity (spaces between cells/ materials)
4) shells very small and hard
Main types of uses
- mineral filler
- mild abrasive
Filtration (small inert parciles, high porosity).
This is the __.
Types of filters
- swimming pools
- sugar refining (thick syrup filterred)
- vegetable oils: removal of pigments
- water and bottled drinks
- liquid soaps
- liquor, beer, etc
- municipal water supplies
- lightweight concrete
- embalming fluid
Diatom shells create a __; gives paint a __
- flattening effect
- a flat or semigloss appearance
Mild abrasive (small, hard inert particles_
- metal polishes
- some shoe polishes
- some cleaners
Insulation (high MP, high porosity to trap air)
- environmentally okay
- doesnt' affect larger animals
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